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The splash-cup dispersal mechanism in plants
Abstract
The late Prof. A. H. R. Buller regarded certain cup-shaped reproductive bodies found among cryptogams as "splash-cups" which make use of the energy of raindrops for the dispersal of spores, sperms, and gemmae. Buller's concepts are presented and supplemented by investigations carried out since his death. Raindrops cause the peridioles of the Nidulariaceae or bird's-nest fungi to be thrown about four feet by splash action. In the genus Cyathus, as a peridiole is jerked out of its cup, the funiculus is torn and this makes possible the expansion of a mass of adhesive hyphae (the hapteron) which clings to any object in the line of flight. The momentum of the peridiole causes a long cord to be pulled out of a sheath attached to the peridiole. The peridiole is checked in flight and the jerk causes the funicular cord to become wound around stems or entangled among plant hairs. Thus the peridiole becomes attached to vegetation and may be eaten subsequently by herbivorous animals. Several morphological features of fruit bodies of the Nidulariaceae are regarded as related to the utilization of the energy of raindrops in rain dispersal and the significance of the splash-cup principle is emphasized. Other splash-cups, the operation of which is described, are: the gemma cups of Marchantia and Lunularia; the antheridial disk of Marchantia; the leaf rosette of the male Polytrichum plant; the sclerotium cups of Aleurodiscus Minnsiae; the cupulate fruits of Sagina decumbens and Oenothera rosea.
... Dispersing propagules away from the parent can reduce competition between offspring and the parent, reduce herbivory near the parent and help offspring populate both rare suitable microhabitats as well as newly available habitats [1]. Splash-cups (here, referring to plants, bryophytes and fungal species) exhibit a rain-activated ballistic dispersal mechanism known as hydroballochory, in which organisms disperse their propagules with help from falling raindrops [2][3][4][5]. Raindrops impact cup-shaped fruiting bodies, and the resulting splash can carry propagules more than a metre away from the parent [2,[5][6][7]. Dispersal distances are of the order of 10 × the parent height in the case of flowering plants, such as Chrysosplenium echinus, and more than 100 × the parent height of liverworts, such as Marchantia polymorpha [5,6]. ...
... In general, the fruiting body of the plant or fungus forms a receptacle in which the propagules develop. When a raindrop hits the fruiting body, it is focussed into a jet and ejected along with the propagules [3,4,8,9]. ...
... Cyathus and Crucibulum spp.) have peridioles with funicular cords, which have been shown to attach to nearby plants [4,8,14]. Here, we tested spherical seed mimics for simplicity, repeatability and availability. ...
Splash-cup plants disperse propagules via raindrops striking cup-shaped fruiting bodies. The seeds are ejected at velocities up to five times the impact speed of the raindrop and are dispersed up to 1 m from the parent plant. Here, we examine the effects of cup angles and the presence of seed mimics to understand the dynamics of this unique method of dispersal. Our findings demonstrate that: (i) cup angles that launched seeds the furthest ranged from approximately 30° to 50°, matching the range of angles seen in splash-cup plants. (ii) Seeds travel shorter distances than water droplets alone, and this distance depends on the number of seeds in the cup. (iii) Not all seeds are ejected from initially dry cups, leaving cups with some seeds and some water. (iv) Nearly all seeds are ejected from cups that contain both water and seeds, and those that are ejected travel significantly further than those from dry cups. These results confirm the possibility that the conical shape of splash cup plants may be adapted to maximize dispersal distance and benefit from multiple splash events. Our results also illustrate that future work on these plants should include seeds rather than water droplets alone.
... When water droplets fall into gemma cups, the gemmae deposited inside the cup are splashed out by a mechanism referred to as "splash-cup" (Brodie 1951). Gemmae have been observed to splash as far as 120 cm away from the parent plant (Equihua 1987). ...
... Thus, if the antheridia and archegonia are isolated without a water layer, sperm cells must be transported by other means. Examples are "splash-launch" by raindrops (Brodie 1951), planing on water using surface tension (Muggoch and Walton 1942), transportation by animals such as springtails and mites (Cronberg et al. 2006), and explosive dispersal of sperm cells into the air (Shimamura 2008). Although explosive sperm dispersal is not very common in bryophytes, it is relatively common in marchantialian liverworts (Thuret 1856, Cavers 1903, Benson-Evans 1950, Crum 2001 As for the means of transportation of sperm cells in fertilization of Marchantia, there is a commonly held view that raindrops strike the disk of the antheridiophore and that splashed water directly carries sperm cells up to the archegonium hanging from the disk of the archegoniophore. ...
... In fact, when raindrops fall onto the antheridial disk, water droplets containing sperm cells can be splashed 30 cm away or farther. Many researchers have confirmed this phenomenon experimentally (Burgeff 1943, Brodie 1951, Duckett and Pressel 2009). However, observation by Duckett and Pressel (2009) led to a question concerning the classical understanding of the fertilization of Marchantia. ...
One of the classical research plants in plant biology, Marchantia polymorpha, is drawing attention as a new model system. Its ease of genetic transformation and a genome sequencing project have attracted
attention to the species. Here I present a thorough assessment of the taxonomic status, anatomy, and developmental morphology
of each organ and tissue of the gametophyte and sporophyte on the basis of a thorough review of the literature and my own
observations. M. polymorpha has been a subject of intensive study for nearly 200 years, and the information summarized here offers an invaluable resource
for future studies on this model plant.
... Asexual propagules, known as gemmae, are assumed to be the main form of asexual dispersal and are the focus of this study. Gemmae are produced by both male and female plants in specialized structures known as gemma cups, which function as splash cups as described by Brodie (1951) . Gemmae of M. infl exa are about 0.2 mm in diameter and are dispersed by water. ...
... A total of 144 males and 144 females were placed singly in a well with a drop of water. Because gemmae are dispersed by rainfall ( Brodie, 1951 ;Equihua, 1987 ) and water, using water and moist soil mimics the immigration process. Gemmae were randomly assigned to one of fi ve drying treatments: (1) zero days dry; (2) one day dry; (3) two days dry; (4) three days dry; or (5) four days dry. ...
... Stieha, personal observation). Intrapopulation dispersal of gemmae from splash cups has been shown to be large, ranging from greater than half a meter ( Brodie, 1951 ) to 1.2 m ( Equihua, 1987 ). Propagules can be dispersed via abiotic factors ( Equihua, 1987 ;Johansson and Nilsson, 1993 ;Walser, 2004 ) or biotic factors ( Kimmerer and Young, 1995 ;Heinken, 1999 ;Parsons et al., 2007 ;Rudolphi, 2009 ). ...
The dispersal process involves emigration from a focal source, dispersal through the landscape, and immigration into a new population or habitat. Despite the fact that dispersal is vital for the long-term persistence of a species, key stages of the process are unknown or understudied for many species, including the importance and contribution of asexual reproduction. Focusing only on a single stage in the dispersal process may give an incomplete and potentially flawed picture of the effects of asexual reproduction on metapopulation dynamics in plant species.
Using a multifaceted approach that combines laboratory experiments, field studies, and mathematical models, we quantify the production, dispersal, and survival of immigrants of water-dispersed asexual offspring (gemmae) of the clonal liverwort Marchantia inflexa.
Compared to female plants, male plants of Marchantia inflexa produce gemmae more quickly and in higher numbers, but due to desiccation have lower gemmae survival rates. Gemmae move up to 20 cm per minute in light rain, suggesting they can leave the source population. Long distance dispersal of gemmae is supported by the mathematical analysis of unisexual metapopulations. Upon reaching the new habitat, gemmae survival is high if they stay moist.
By integrating multiple experiments to quantify the effects of gemmae on metapopulation dynamics, we found that different stages of dispersal can lead to different conclusions on which sex has an advantage. Gemmae are critical for the maintenance of both sexes, the persistence of single-sex metapopulations and species, and the invasibility of clonal organisms.
... Each peridium contains small egg-like packets called peridioles (Fig. 1), which are composed of hyphae, basidia and basidiospores. Bird's nest fungi peridioles are believed to disperse by rain or water splash and remain intact after dispersal (Brodie 1951). In a morphologically similar fungus, Sphaerobolus (Geastrales), a single peridiole is produced and actively discharged from the peridium (Geml et al., 2005). ...
... It has been estimated that 2e3 million basidiospores are packaged inside each peridiole (Hassett et al., 2015). Not much is known regarding what happens to the peridioles after their dispersal or how bird's nest fungi successfully disseminate over long distances (Brodie 1951;Malloure and James 2013). Brodie (1975) theorized that grazers accidently consume peridioles, which then break down inside the animal intestines and disperse via dung. ...
Fungi in the Nidulariaceae, otherwise known as ‘bird’s nest fungi’, are among the least studied groups of Agaricomycetes (Basidiomycota). Bird’s nest fungi are globally distributed and typically grow on woody debris or animal dung as saprotrophs. This group of fungi is morphologically diverse with ca. 200 described species. Phylogenetic relationships of bird’s nest fungi were investigated with four commonly used loci (ITS, LSU, tef, and rpb2). The family was resolved as a monophyletic group with Squamanitaceae as a potential sister taxon. Cyathus and Crucibulum formed well-supported clades independently. Nidula and Nidularia formed a clade together, but each genus is polyphyletic. Two Mycocalia species included in our analyses were on their own separate branches, indicating that this genus is also polyphyletic. Misidentifications were detected in most genera, suggesting that species concepts need to be revisited and refined throughout Nidulariaceae. Several bird’s nest fungi species have global geographical distributions whereas others may have more limited ranges. Basic morphological characters of bird’s nest fungi have likely been lost or gained multiple times. The phylogenetic placement of Crucibulum is unclear and the sister lineage of bird’s nest fungi is not conclusive. Further studies with data from rare species and additional informative genes are needed to fully resolve the topology of Nidulariaceae and identify its sister group with more certainty.
... Each peridium contains small egg-like packets called peridioles (Fig. 1), which are composed of hyphae, basidia and basidiospores. Bird's nest fungi peridioles are believed to disperse by rain or water splash and remain intact after dispersal (Brodie 1951). In a morphologically similar fungus, Sphaerobolus (Geastrales), a single peridiole is produced and actively discharged from the peridium (Geml et al., 2005). ...
... It has been estimated that 2e3 million basidiospores are packaged inside each peridiole (Hassett et al., 2015). Not much is known regarding what happens to the peridioles after their dispersal or how bird's nest fungi successfully disseminate over long distances (Brodie 1951;Malloure and James 2013). Brodie (1975) theorized that grazers accidently consume peridioles, which then break down inside the animal intestines and disperse via dung. ...
The “bird’s nest” fungi (Nidulariaceae) are charismatic mushrooms that look like small nests containing multiple tiny eggs. Because the ecological role of bird’s nest fungi is to decompose wood, they are extremely common in disturbed areas with plant debris and mulch, such as trails and backyard gardens. These fungi tend to grow in large clusters, so it is common to see ten to a hundred of these “nests” at once. Bird’s nest fungi are not considered dangerous to plants, animals, or humans. This new 3-page publication of the UF/IFAS Plant Pathology Department was written by Nattapol Kraisitudomsook and Matthew E. Smith.https://edis.ifas.ufl.edu/pp361
... A similar seed dispersal mechanism may be found on other herbaceous plants from moist environments that have triquetrous capsules, such as Monolena and Triolena. Another seed dispersal mechanism effected by rain is the 'splash-cup mechanism' (Brodie, 1951;Nakanishi, 2002). Although it has not been tested, it could occur in genera of Bertolonieae s.l. that have trumpet-like capsules, such as Salpinga and Macrocentrum. ...
... Although it has not been tested, it could occur in genera of Bertolonieae s.l. that have trumpet-like capsules, such as Salpinga and Macrocentrum. In this case, rain drops are caught by trumpet-or cup-shaped capsules and the seeds are expelled with the splashing water (Brodie, 1951;Pizo & Morellato, 2002). The limited range of seed dispersal resulting from these mechanisms may help explain the high level of endemism and habit specificity of most species in Bertolonieae s.l. ...
Bertolonieae (Melastomataceae) have traditionally comprised > 100 Neotropical species in Bertolonia, Boyania, Macrocentrum, Monolena, Salpinga and Triolena and another six species in the monospecific genera Diolena, Diplarpea, Maguireanthus, Opisthocentra, Tateanthus and Tryssophyton. The position of the tribe inside or outside Sonerileae has been discussed since the first classifications of Melastomataceae. These tribes were always considered closely related because of overall similar morphology, mainly herbaceous habit and angular fruits. Previous phylogenetic analyses have shown that Bertolonieae as traditionally circumscribed are not monophyletic and require re-evaluation. These previous results also led to questions on why such herbaceous plants from shaded, moist habitats and with angular fruits had evolved so many times in different and geographically/phylogenetically distant groups of Melastomataceae. We conducted molecular phylogenetic analyses in order to evaluate tribal and generic limits, reconstruct morphological patterns and identify clades in the tribe. To infer the monophyly of Bertolonieae and the genera that were traditionally included in the tribe we analysed three plastid (ndhF, rbcL and rpl16) and two ribosomal (nrETS and nrITS) DNA markers, using maximum likelihood and Bayesian inference in individual and variously combined data sets comprising up to 6646 characters and 445 terminals. Bertolonieae as traditionally recognized were recovered in four major lineages across the tree. Bertolonieae are recircumscribed here to include only Bertolonia. A new tribe, Trioleneae, with the genera Monolena and Triolena is described on the basis of molecular, geographical and morphological evidence. Our study also shows that the combination of herbaceous habit and angular capsules has evolved several times in Melastomataceae. Besides the taxonomic changes proposed here, the molecular corroboration that Bertolonieae s.l. are not monophyletic and the geographical and morphological congruence found in these lineages, the convergence of morphological characters historically used to identify Bertolonieae s.l. might be explained by the occupation of similar habitats in different places across the world, i.e. in mostly shaded and moist herbaceous layers under the rainforest canopy. The dependence on water for seed dispersal and the limited dispersability could also explain the restriction of the taxa to a limited area or vegetation type.
... The gemmae are thought to fall passively to the base of the parental shoot, and then to be possibly carried further away by rain-water (Reese, 1997) or dispersed by wind (Schuster, 1966). In some bryophytes the propagules are formed in specialized gemma-cups with "splash-cup" mechanisms similar to those thought to disperse sperm in many species of the Polytrichaceae and Mniaceae (Brodie, 1951). Such gemma-cups occur, for instance, in thalloid hepatics, e.g., in Marchantia polymorpha, and in the moss Tetraphis pellucida. ...
... Such gemma-cups occur, for instance, in thalloid hepatics, e.g., in Marchantia polymorpha, and in the moss Tetraphis pellucida. In gemma-cups the gemmae become loose when ripened, and splashes of falling rain drops push the gemmae over the edges of the cup, thus providing a chance to be carried further away with water currents (Brodie, 1951). The shape of the gemma-cup may also affect turbulence, thus facilitating the dispersal by air-currents. ...
Dispersal ability is of a great importance for bryophytes, which commonly occupy spatially limited habitat patches. Distance dispersal of bryophytes has been thought to take place primarily by spores. However, another potential mechanism is dispersal by diaspores which are not produced by meiosis following sexual reproduction, such as gemmae or leaf fragments, but there has been rather limited information on the distances and frequencies such propagules travel. In the present paper, we summarise what is known of the spatial and temporal dispersal of asexual bryophyte propagules. Based on previous studies and on our own investigations, it is evident that asexual propagules may have a significant role in the dynamic processes of bryophyte populations.
... We note that our optimal angle of 408 disagrees with Brodie's previous conjecture that the most efficient splash-cups have opening angles of 608-708 based upon his observations of the bird's nest fungus which has an opening angle of 60-708 [62]. Brodie's result is not inconsistent with our own. ...
... Brodie's result is not inconsistent with our own. Instead, the systems he studied are probably focused on vertical rather than horizontal dispersal: the splashes on bird's nest fungus serve to shoot tendrils at the maximum height in order to reach taller plants [62]. Plants that shoot for vertical dispersal will indeed have higher optimal angles. ...
The conical flowers of splash-cup plants Chrysosplenium and Mazus catch raindrops opportunistically, exploiting the subsequent splash to disperse their seeds. In this combined experimental and theoretical study, we elucidate their mechanism for maximizing dispersal distance. We fabricate conical plant mimics using three-dimensional printing, and use high-speed video to visualize splash profiles and seed travel distance. Drop impacts that strike the cup off-centre achieve the largest dispersal distances of up to 1 m. Such distances are achieved because splash speeds are three to five times faster than incoming drop speeds, and so faster than the traditionally studied splashes occurring upon horizontal surfaces. This anomalous splash speed is because of the superposition of two components of momentum, one associated with a component of the drop's motion parallel to the splash-cup surface, and the other associated with film spreading induced by impact with the splash-cup. Our model incorporating these effects predicts the observed dispersal distance within 6-18% error. According to our experiments, the optimal cone angle for the splash-cup is 40°, a value consistent with the average of five species of splash-cup plants. This optimal angle arises from the competing effects of velocity amplification and projectile launching angle.
... This result fits our field observations that large female patches bear sporophytes of their entire surface area and not just along the edges, which is rather the consequence of large male gamete dispersal and not male and female genets being intermingled (see 'Genetic structure and mode of reproduction' above). The relatively large dispersal capacity of the male gametes of P. formosum and probably other Polytrichum species is most likely due to the fact that sexually active male gametophytes of these species bear splash-cups (Brodie 1951). ...
... This may explain why in the situation shown in Fig. 3(b) the large, but more distant, male M2 fathered 1.77 times as many sporophytes as the nearer, but smaller, male M1. Spermatozoids of mosses differ from pollen by the fact that they bear flagella and can actively swim, but most dispersal of male gametes is thought to occur passively by being carried by water and, in the case of Polytrichum, through the splash cup mechanism (Brodie 1951). To explore this possibility, we assumed that in P. formosum the gamete dispersal curve follows the negative exponential function y x = ae – bx , as postulated for pollen deposition in wind pollinated plants (Giddings et al. 1997; Van Raamsdonk & Schouten 1997), in which a = number of gametes at source, b = fraction of gametes deposited per unit distance, x = distance to source, y x = number of gametes deposited at distance x. ...
Using highly polymorphic microsatellite markers, we assessed clonal structure and paternity in a population of the bryophyte species Polytrichum formosum. Identical multilocus genotypes of individual shoots were almost never observed in spatially separated cushions, but were found to be highly clustered within moss cushions. Therefore, asexual reproduction through dispersal of gametophyte fragments is not very important in P. formosum. However, asexual reproduction on a very localized scale through vegetative growth of genets (branching of gametophytes via clonal growth of rhizomes) is very extensive. The patchy spatial distribution of genets and the absence of intermingling among genets suggest that this species follows a 'phalanx' clonal growth strategy. Vegetative proliferation of genets will increase their size, and, consequently, will have considerable fitness consequences for individuals in terms of increased genet longevity and reproductive output. Although paternity analysis of sporophytes confirmed male genet size, i.e. gamete production, to be an important determinant of male reproductive fitness, it also showed that the spatial distance to female genets is the predominant factor that governs male reproductive success. Moreover, we showed that male gamete dispersal distances in P. formosum are much further than generally assumed, and are in the order of metres rather than centimetres. Combining the findings, we conclude that the high genotypic diversity observed for this facultatively clonal species is most likely explained by a preponderance of sexual reproduction over clonal reproduction.
... Genetic differentiation greatly depends on breeding systems, pollination and dispersal modes, demographic history, ecological attributes, and many other factors [55][56][57] . Given the short dispersal distances of seeds via splash rain seed dispersal mechanisms typically found in the genus and family [58][59][60] , the low level of population differentiation in P. latiovalifolius was unexpected and contrasted with P. takesimensis on Ulleung Island 26 . We hypothesize that the two geographically disjunct patterns among populations in P. latiovalifolius, corroborated by PCA and genetic structure analyses, could be formed by postglacial contraction (i.e., vicariance resulting from climate-related population fragmentation and local extinction during interglacial periods) rather than by long-distance dispersal. ...
Phedimus latiovalifolius (Y.N.Lee) D.C.Son & H.J.Kim is exclusively distributed in the high mountains in the Korean Peninsula, mainly along the Baekdudaegan mountain range. Despite its morphological and distributional distinction from other Phedimus Raf. species, its taxonomic identity and phylogenetic relationship with congeneric species remain unclear. This study employs genotyping-by-sequencing-derived genome-wide single nucleotide polymorphisms to establish the monophyly of P. latiovalifolius and its relationship with closely related species. Genetic diversity and population differentiation of P. latiovalifolius are also assessed to provide baseline genetic information for future conservation and management strategies. Our phylogenetic analyses robustly demonstrate the monophyletic nature of P. latiovalifolius, with P. aizoon (L.) ‘t Hart identified as its closest sister lineage. There is no genetic evidence supporting a hybrid origin of P. latiovalifolius from P. aizoon involving either P. ellacombeanus (Praeger) ‘t Hart or P. kamtschaticus (Fisch.) ‘t Hart. Population genetic analyses reveal two major groups within P. latiovalifolius. A higher genetic variation is observed in P. ellacombeanus than in the congeneric species. Notably, most of the genetic variation exists within P. latiovalifolius populations. Given its distribution and the potential role of Baekdudaegan as an East Asian Pleistocene refugia, P. latiovalifolius could be considered rare and endemic, persisting in the refugium across glacial/interglacial cycles.
... Splash-out and squirt-corner have been reported for species of Sonerileae and Bertolonieae (Cellinese, 1997;Pizo and Morellato, 2002). Such mechanisms are linked with specialized diaspore structures (Hartmann, 1988) that allow seed ejection with water drops (Brodie, 1951). However, in contrast to species in these tribes, the loculicidal fruits and seeds of Microlicia lack specialized structures that can facilitate any wind-or water-operated dispersal mechanism. ...
Understanding dispersal systems is a key step towards improving our ability to predict species migration upwards in face of climate change. However, the abiotic seed dispersal systems of tropical plants remain much overlooked, despite its key role in shaping species distribution in face of changing environmental conditions. We experimentally tested the seed dispersal mode, determined seed dispersal season, and estimated dispersal distance kernels for five mountaintop, edaphic specialist species from a tropical, megadiverse and nutrient-impoverished grassland. Contrary to previous studies, we found no evidence of water- or wind-operated seed dispersal mechanisms in the study species. We show that fruiting peaks coincided with optimum conditions for establishment, and that short seed dispersal distances are consistent with the idea of reduced dispersibility in edaphic specialists. Our data suggest that abiotic dispersal in the study species plays limited role in displacing seeds away from the parental plants, a pattern that markedly contrasts with that found in forests. Short distance dispersal represents reason for concern in face of global climate changes. The combination of edaphic endemism and limited dispersal in our mountaintops species poses a significant threat to their long-term survival.
... For instance, gemmae are asexual propagules of gametophytic tissue that are used as haploid dispersal agents by various seedless plants, such as in the splash cups of the liverworts Marchantia L. (Marchantiaceae) and Lunularia Adans. (Lunulariaceae) and the fern genus Vittaria Sm. (Pteridaceae) (Brodie, 1951;Emigh and Farrar, 1977;Equihua, 1987; Figure 1B). ...
Dispersal of gametophytes is critical for land plant survivorship and reproduction. It defines potential colonization and geographical distribution as well as genetic mixing and evolution. C. T. Ingold's classic works on Spore Discharge in Land Plants and Spore Liberation review mechanisms for spore release and dispersal based on real‐time observations, basic histology, and light microscopy. Many mechanisms underlying spore liberation are explosive and have evolved independently multiple times. These mechanisms involve physiological processes such as water gain and loss, coupled with structural features using different plant tissues. Here we review how high‐speed video and analyses of ultrastructure have defined new biomechanical mechanisms for the dispersal of gametophytes through the dissemination of haploid diaspores, including spores, pollen, and asexual reproductive propagules. This comparative review highlights the diversity and importance of rapid movements in plants for dispersing gametophytes and considerations for using combinations of high‐speed video methods and microscopic techniques to understand these dispersal movements. A deeper understanding of these mechanisms is crucial not only for understanding gametophyte ecology but also for applied engineering and biomimetic applications used in human technologies.
... Mature gemmae cups (3) act as splash cups with raindrops displacing the uppermost gemmae away from the parental plant (Brodie, 1951). For nearly the past two centuries the irreversible dorsiventrality induced in the initially "two-sided" lenticular gemmae (4) by light (primarily) and gravity has been investigated [see (Bowman, 2016) for review]. ...
The liverwort Marchantia polymorpha has been known to man for millennia due to its inclusion Greek herbals. Perhaps due to its familiarity and association with growth in, often, man-made disturbed habitats, it was readily used to address fundamental biological questions of the day, including elucidation of land plant life cycles in the late 18th century, the formulation of cell theory early in the 19th century and the discovery of the alternation of generations in land plants in the mid-19th century. Subsequently, Marchantia was used as model in botany classes. With the arrival of the molecular era, its organellar genomes, the chloroplast and mitochondrial, were some of the first to be sequenced from any plant. In the past two decades, molecular genetic tools have been applied such that genes may be manipulated seemingly at will. Here, are past, present, and some views to the future of Marchantia as a model.
... Thismia panamensis flowering and fruiting occur in the rainy season. The species has an inferior ovary that, when developed, forms a dehiscent fruit, with exposed seeds (Guilherme et al. 2016), similar to other species of Thismia (Brodie 1951;Mar & Saunders 2015). These characteristics of fruit and seed indicate that dispersal may occur by raindrop splash (Mar & Saunders 2015), although, to date, there are no records in the literature on this dispersal strategy for the genus. ...
• Species of the genus Thismia Griff. are small herbs considered mycoheterotrophic, due to an intimate relationship with fungi. They are achlorophyllous, with complex floral structure andlittle information on reproductive strategies.. This study evaluated structural and ecological aspects associated with the dispersal of seeds of Thismia panamensis (Standley) Jonk.
• The study was carried out in a forest fragment in the Brazilian Cerrado. During the reproductive period, 36 individuals were monitored for the spatial distribution of the population and their fruits were collected. Samples were subjected to light microscopy and microtomography techniques, in addition to an experiment to evaluate seed dispersal by water droplets.
• T. panamensis is up to 8 cm tall, with tuberous root and stem, without leaves. Its fruit is dehiscent, cup‐shaped, 5 ± 1 mm in diameter, containing 219.33 ± 106.70 seeds, with average length of 0.55 ± 0.07 mm. The seeds are exposed and their coat has a thin and lignified wall. Accumulation of secretion was observed inside the fruits. The innermost cell layer of the ovary showed typical characteristics of aquiferous parenchyma. Water splash experiments showed that the seeds reached an average distance of 44.04 ± 26.58 cm. Each splash had on average 1.50 ± 1.23 seeds, with 75% of the splashes containing a single seed. A total of 239 seeds were counted in the 163 splashes evaluated.
• The data show potential seed dispersal by ombrohydrochory in T. panamensis, favoring its maintenance in the study area and reflecting its clumped spatial distribution.
... Therefore, P. takesimensis showed apparent population genetic structure and differentiation after its divergence from the continental progenitor species. Given the fruit type of P. takesimensis are aggregates of follicles, with the fruit opening along an upward facing suture (i.e., cup-shaped), and with small light-weighted seeds, it is highly conceivable that raindrops are responsible for splashing out and flushing away seeds over some distances [71][72][73]. This type of splash rain dispersal mechanism was documented for Sedum formosanum and S. subtile from the same family (Crassulaceae) in Japan and it was shown experimentally that the maximum seed dispersal distance of S. subtile was 63.7 ± 7.8 cm [73]. ...
Phedimus takesimensis (Ulleungdo flat-leaved stonecrop) is endemic to Ulleung and Dokdo Islands off the east coast of the Korean Peninsula. It was suggested that P. takesimensis originated via anagenetic speciation from the continental progenitor species P. kamtchaticus or P. aizoon. However, little is known of the phylogenetic relationships and population genetic structure among species of Phedimus in the Korean Peninsula and Ulleung/Dokdo Islands. We inferred the phylogenetic relationships among congeneric species in Korea based on nuclear ribosomal DNA internal transcribed spacer and chloroplast noncoding regions. We also sampled extensively for P. takesimensis on Ulleung Island and the continental species, P. kamtschaticus and P. aizoon, to assess the genetic consequences of anagenetic speciation. We found (1) the monophyly of P. takesimensis, (2) no apparent reduction in genetic diversity in anagenetically derived P. takesimensis compared to the continental progenitor species, (3) apparent population genetic structuring of P. takesimensis, and (4) two separate colonization events for the origin of the Dokdo Island population. This study contributes to our understanding of the genetic consequences of anagenetic speciation on Ulleung Island.
... (Hughes 1962) or archegonia was found, in which case the number of archegonia present was documented. Males were categorized based on splash cup presence (Brodie 1951), and all splash cups were examined for viable antheridia containing male sperm. In these species, male splash cups serves as innate markers (Bu 2005); while for females reproduction in terms of fertilization and sporophyte production is fatalistic (Greene 1960;Sarafis 1971;Watson 1975;Callaghan et al. 1978 ...
... Plants can use water in three basic ways to move rapidly. They can directly capture the kinetic energy in a falling raindrop (Brodie 1951;Nakanishi 2002). Based on water loss, they can build up elastic energy through compression or tension. ...
Plants moved onto land ∼450 million years ago and faced their biggest challenge: living in a dry environment. Over the millennia plants have become masters of regulating water flow and the toolkit they have developed has been co-opted to effect rapid movements. Since plants are rooted, these fast movements are used to disperse reproductive propagules including spores, pollen, and seeds. We compare five plants to demonstrate three ways, used alone or in combination, that water powers rapid movements: the direct capture of the kinetic energy of a falling raindrop propels gemmae from the splash cups of the liverwort, Marchantia; the loss of water powers the explosive dispersal of the spores of Sphagnum moss; the alternate loss and gain of water in the bilayer of the elaters of Equisetum drive the walk, jump and glide of spores; the gain of water in the inner layer of the arils of Oxalis drive the eversion of the aril that jettisons seeds from the capsule; and the buildup of turgor pressure in the petals and stamens of bunchberry dogwood (Cornus canadensis) explosively propels pollen. Each method is accompanied by morphological features, which facilitate water movement as a power source. The urn shaped splash cups of Marchantia allow dispersal of gemmae by multiple splashes. The air gun design of Sphagnum capsules results in a symmetrical impulse creating a vortex ring of spores. The elaters of Equisetum can unfurl while they are dropping from the plant, so that they capture updrafts and glide to new sites. The arils of Oxalis are designed like miniature toy "poppers". Finally, in bunchberry, the softening of stamen filament tissue where it attaches to the anther allows them to function as miniature hinged catapults or trebuchets.
... Exogenous ABA Delays Growth Initiation of Dormant Gemmae M. polymorpha gemmae are dormant when they are in the cup, suggesting the cup produces an inhibitor of germination [6]. When displaced from the cups, e.g., via raindrops [8], gemmae commence their development. To analyze whether exogenous abscisic acid (ABA) affects gemma dormancy, we transferred dormant wild-type gemmae from gemma cups to medium containing ABA and observed their development over nine days. ...
Dormancy is a key process allowing land plants to adapt to changing conditions in the terrestrial habitat, allowing the cessation of growth in response to environmental or physiological cues, entrance into a temporary quiescent state, and subsequent reactivation of growth in more favorable environmental conditions [1-3]. Dormancy may be induced seasonally, sporadically (e.g., in response to drought), or developmentally (e.g., seeds and apical dominance). Asexual propagules, known as gemmae, derived via clonal reproduction in bryophytes, are often dormant until displaced from the parent plant. In the liverwort Marchantia polymorpha, gemmae are produced within specialized receptacles, gemma cups, located on the dorsal side of the vegetative thallus [4]. Mature gemmae are detached from the parent plant but may remain in the cup, with gemma growth suppressed as long as the gemmae remain in the gemma cup and the parental plant is alive [5]. Following dispersal of gemmae from gemma cups by rain, the gemmae germinate in the presence of light and moisture, producing clonal offspring [6]. In land plants, the plant hormone abscisic acid (ABA) regulates many aspects of dormancy and water balance [7]. Here, we demonstrate that ABA plays a central role in the control of gemma dormancy as transgenic M. polymorpha gemmae with reduced sensitivity to ABA fail to establish and/or maintain dormancy. Thus, the common ancestor of land plants used the ABA signaling module to regulate germination of progeny in response to environmental cues, with both gemmae and seeds being derived structures co-opting an ancestral response system.
... Both sexes can reproduce asexually by both asexual propagules and extension by growth. Asexual propagules (gemmae within a cup) are produced on the thallus surface and are dispersed by water (Brodie, 1951). The gemmae can be dispersed aerially by water splashing in the cup (within-patch dispersal) or downstream by floating in flowing water (among-population dispersal) (C. ...
Background and aims:
In dioecious plants, sexual reproduction requires close proximity to potential mates, but clonal growth can increase this distance and, therefore, reduce the probability of mating. Reduction in sexual propagules can lead to decreased dispersal and gene flow between populations. Gene flow and clonal growth may be further influenced by the size of the habitat patch. The effects of habitat size and reproductive mode (sexual or asexual reproduction) on spatial genetic structure and segregation of the sexes were tested by quantifying the distributions of genotypes and the sexes using the dioecious liverwort Marchantia inflexa.
Methods:
Plants were sampled from five pairs of small-large habitat patches to identify within- and among-population spatial genetic structure using 12 microsatellite markers. Spatial distributions were calculated as the likelihood that pairs of individuals were the same sex or genotype, and it was determined how that likelihood was affected by habitat patch size (small/large).
Key results:
Asexual reproduction dominates within populations, and asexual dispersal also occurred across populations. Spatial segregation of the sexes was observed within populations; males were more likely to be near individuals of the same sex than were females. Although the likelihood of both sexes being near members of the same sex was similarly greater on small habitat patches, on large habitat patches male genotypes were almost 15 % more likely to be near clonemates than were female genotypes.
Conclusions:
The results show a sex difference in clonal clumping that was dependent upon habitat size, suggesting differential colonization and/or survival between males and females. The sexes and genotypes being structured differently within and among populations have implications for the persistence of populations and the interactions between them. This study demonstrates that studying only the sexes and not their genotypes (or vice versa) can limit our understanding of the extent to which reproductive modes (sexual or asexual) influence genetic structure both within and between populations.
... So far, different processes of sperm transportation have been proposed [23] 1 , including 'splash-launch' by raindrops [26], surfing on an air -water interface & 2018 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, ...
The female sex organ of the liverwort (Marchantia polymorpha) has a characteristic parasol-like form highly suitable for collecting water droplets containing sperm for fertilization. Motivated by this observation and using three-dimensional printing techniques, we develop a parasol-like rigid object that can grab, transport and release water droplets of a maximum size of about 1 cm. By combining experiments and scaling theory, we quantify the object's fundamental wetting and fluid dynamical properties. We construct a stability phase diagram and suggest that it is largely insensitive to properties of liquids such as surface tension and viscosity. A simple scaling argument is developed to explain the phase boundary. Our study provides basic design rules of a simple pipette-like device with bubble-free capture and drop of liquids, which can be used in laboratory settings and has applications within soft robotics. Through systematic experimental investigations, we suggest the optimal design criteria of the liverwort-inspired object to achieve maximal pipetting performance. We also provide, based on our scalable model experiments, a biological implication for the mechanistic advantage of this structure in liverwort reproduction.
... Although there is extensive literature about how water is handled by mosses (e.g., Brodie 1951;Bates 1988;Davey & Ellis-Evans 1996;Mulder et al. 2001;Rixen & Mulder 2005;Sand-Jensen & Hammer 2012), so far, however, there are no experimental data documenting the process of capturing water drops and distributing them to adjacent shoots within a moss clump. This study attempts to describe this phenomenon based on the endohydric moss species Polytrichastrum formosum. ...
The study concerns the mechanics and water relationships of clumps of a species of endohydric moss, Polytrichastrum formosum .
Anatomical and morphological studies were done using optical and scanning electron microscopy. Experiments on waterdrop capture and their distribution to adjacent shoots within a moss clump were performed with the experimental set‐up for the droplet collision phenomena and ultra‐high speed camera. The mechanical strength of the moss clump was tested on an electromechanical testing machine.
During the process of moss clump wetting, the falling water drops were captured by the apical stem part or leaves, then flowed down while adhering to the gametophore and never lost their surface continuity. In places of contact with another leaf, the water drop stops there and joins the leaves, enabling their hydration. Mathematical analysis of anatomical images showed that moss stems have different zones with varying cell lumen and cell wall/cell radius ratios, suggesting the occurrence of a periodic component structure. Our study provides evidence that the reaction of mosses to mechanical forces depends on the size of the clump, and that small groups are clearly stronger than larger groups.
The clump structure of mosses acts as a net for falling rain droplets. Clumps of Polytrichastrum having overlapping leaves, at the time of loading formed a structure similar to a lattice. The observed reaction of mosses to mechanical forces indicates that this phenomenon appears to be analogous to the ‘size effect on structural strength’ that is of great importance for various fields of engineering.
... Recent work by Casanova-Katny et al., 2016 has found more P. alpinum sporophytes on Fildes Peninsula with OTC warming, consistent with the pattern of increased sexual expression observed in this study. It should be noted that sexually expressing P. alpinum males have (the relatively uncommon) splash cups (Fig. 1B), which are known to increase moss sperm dispersal (as water droplets fall in the splash cup, the sperm are ejected) (Brodie, 1951). If, with warming, more male gametophytes express gametangia with splash cups, sperm dispersal is likely to increase. ...
Background and aims:
The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth, and many biotic communities inhabiting this dynamic region are responding to these well-documented climatic shifts. Yet some of the most prevalent organisms of terrestrial Antarctica, the mosses, and their responses to warming have been relatively overlooked and understudied. In this research, the impacts of 6 years of passive warming were investigated using open top chambers (OTCs), on moss communities of Fildes Peninsula, King George Island, Antarctica.
Methods:
The effects of experimental passive warming on the morphology, sexual reproductive effort and stress physiology of a common dioicous Antarctic moss, Polytrichastrum alpinum ,: were tested, gaining the first species-specific mechanistic insight into moss responses to warming in the Antarctic. Additionally community analyses were conducted examining the impact of warming on overall moss percentage cover and sporophyte production in intact Antarctic moss communities.
Key results:
Our results show a generally greater percentage moss cover under warming conditions as well as increased gametangia production in P. alpinum Distinct morphological and physiological shifts in P. alpinum were found under passive warming compared with those without warming: warmed mosses reduced investment in cellular stress defences, but invested more towards primary productivity and gametangia development.
Conclusions:
Taken together, results from this study of mosses under passive warming imply that in ice-free moss-dominated regions, continued climate warming will probably have profound impacts on moss biology and colonization along the Western Antarctic Peninsula. Such findings highlight the fundamental role that mosses will play in influencing the terrestrialization of a warming Antarctica.
... Both males and females produce asexual propagules (gemmae) that are around 0.12 mm in diameter (McLetchie and Puterbaugh 2000). These gemmae are dislodged out of splash cups by rain (Brodie 1951), dispersed by water (Schuster 1992), and can maintain singlesex metapopulations (Stieha et al. 2014). Sexual propagules (spores) are about 28 lm and wind dispersed (Schuster 1992) and are assumed to be the dominant form of long-distance dispersal (Longton and Schuster 1983). ...
Clonal organisms persist at a range of population sex ratios, from equal numbers of males and females to single-sex systems. When intersexual competition is strong enough to drive one sex locally extinct, the maintenance of the sexes is facilitated by the semi-independent dynamics of populations within a metapopulation. These semi-independent dynamics are influenced by dispersal and recolonization rates, which are affected by the spatial arrangement of populations. To establish the quantitative relationship between spatially complex metapopulations and the maintenance of the sexes, we used a mathematical model of the liverwort Marchantia inflexa. This clonal organism is found in discrete patches on rocks and along the banks of streams, which form single-sex and two-sex metapopulations. In this system, asexual propagules mainly disperse short distances. Long-distance between-patch dispersal and recolonization mainly occurs via sexual propagules, which require both sexes to be present. Dispersal of these two types of propagules could interact with the spatial arrangement of populations to affect the maintenance of the sexes. With our mathematical model, we found that at intermediate distances between populations, metapopulations maintained both sexes, and the spatial arrangement of populations changed the threshold at which one sex was lost. On the other hand, when populations were close to one another, one sex was lost and the single-sex metapopulation persisted through dispersal of asexual propagules. When populations were far apart, one sex was lost, and the metapopulation either went extinct due to lack of recolonization by asexual propagules or persisted because clumped populations facilitated recolonization. These idealized spatial arrangements help clarify the effects of the spatial arrangement on the maintenance of the sexes and the persistence of metapopulations of clonal organisms, which can help explain geographic parthenogenesis and the distribution of asexual populations, the persistence of asexual species, and inform the conservation of clonal organisms.
... The tiny drops produced by a variety of mechanisms by the impact of drops and splashes are responsible for seeding the atmosphere with the salt grains that act as condensation nuclei for rain (Blanchard & Woodcock 1957). In plant physiology one talks of the splash-cup dispersal mechanism (Brodie 1951), according to which the tiny drops produced by raindrops hitting the splash cup are responsible for the dispersal of spores and gemmae of certain plants. ACKNOWLEDGMENTS ...
Experiment and theory give very strong indications that most of the underwater noise of rain in the region between 8–10 kHz and 20–25 kHz is due to the oscillations of bubbles entrained by the rain drops impacting on the ocean’s surface. We present a theoretical calculation of the noise spectrum of this process and examine the effects of viscosity and other factors on this result. It is found that neglect of dissipative effects can lead to bubble sizes greater than observed experimentally.
... In drying material it was also observed that hymenia, hyphophores and parts of campylidia were eaten by insects (Psocoptera), which may play a role for dispersal in nature. If rainwater is considered as the principal agent, the dispersal method might be similar to the splash-cup mechanism (Brodie 1951;cf. Lucking 1994). ...
The taxonomy of the foliicolous members of Arthoniaceae (Arthonia, Arthothelium, Cryptothecia, Ermothecella) in Costa Rica is revised.Cryptothecia farkasiaesp. nov. is described, being closely related toStirtonia sprucei, and bearing pycnidia reminiscent ofEremothecella. Arthonia lividofuscais placed in synonymy withA. aciniformis. Pycnidia and pycnospores are further described forArthonia leptosperma, A. cyanea, A. palmulacea, A. trilocularis, Arthothelium cingulatum, Stirtonia spruceiandS. macrocephala, and campylidia were found on thalli ofArthonia aciniformis. Arthonia nigratulaandCryptothecia candidaare reported for the first time from Costa Rica, and new localities are given for previously reported species. Ecological data are provided, and the relationships between foliicolous members of the Arthoniaceae are discussed.
... In contrast, Marchantia sperms did not show such rheotaxis under microscopic observation with a microfluidic device for sperm selection (data not shown), supporting view that the effective delivery of sperms from the male colony to the female colony are likely achieved by the flow of water. As alternative delivery pathways of bryophyte sperms to female gametangia, some transportation, such as direct transportation by microarthropods (Cronberg et al., 2006), "splash-launch" by rain drops (Brodie, 1951) and spouting out into the air (Shimomura et al., 2008), have also been reported. Because these delivery pathways supposed to be not sufficient for the invasion into the "narrow" oviduct of archegonium in archegonial receptacle of female strains, motility of Marchantia sperms might play a key role in the fertilization step, and the estimated migration distance is long enough for that purpose when they are delivered at high motile state, desirably, immediately (within 5 min) after the discharge. ...
Some of the plant species including embryophytes (especially, bryophytes and ferns) utilize the sperms but not pollens for their sexual reproduction. Because sperm motility is one of the most important features for the fertility in human and animals, percentage of motility and the kinetic parameters for swimming and the guidance to eggs (taxis) are well focused in the field of reproductive biology to evaluate and improve the male infertility. However, the nature of plant sperms is rarely known even more than a century has passed since the first microscopic observations of sperms in embryophytes as in the cases in Ginkgo biloba and Cycas revoluta, commonly known as sperm-generating plant species, have been made in the end of 19th century. In the present study, we performed high throughput analysis on the sperm motility in the most common liverwort, Marchantia polymorpha L. using a Computer-Assisted Sperm Analyzing (CASA) system. Time-dependent changes in kinetic parameters of Marchantia sperm motility from high to low motility states suggested that amplitude of lateral head displacement, rather than its frequency play key roles in the speed and distance of swimming at high motility state. From the average lifetime of high motility state and the speed of migration, the distance traveled by Marchantia sperms, due to their own motility, are estimated to be less than 3 cm, suggesting that motility of Marchantia sperms might mainly play a key role in the final fertilization step, but not in the long-distance travelling from the patchily distributed colonies of male strains to those of female strains, often being apart by few meters in the field.
... In some complex thalloid liverworts, such as Marchantia polymorpha and Lunularia cruciata, disc-formed propagules called gemmae are formed in cup-like structures, called gemma cups, on the dorsal side of the dorsiventral haploid thallus (Barnes and Land, 1908). Mature gemmae are a means of asexual reproduction and remain dormant in the cup until dispersed (Molish, 1922), which in natural conditions generally is a result of rainfall (Brodie, 1951). Once the gemmae has been splashed out of the gemma cup, dormancy is released and initiation of growth occurs within hours, leading to the hypothesis that the parent plant secretes a gemma growth inhibitor, much in the same way as the fruit was thought to secrete a seed germination inhibitor (Molish, 1922). ...
The plant hormone auxin (indole-3-acetic acid [IAA]) has previously been suggested to regulate diverse forms of dormancy in both seed plants and liverworts. Here, we use loss- and gain-of-function alleles for auxin synthesis- and signaling-related genes, as well as pharmacological approaches, to study how auxin regulates development and dormancy in the gametophyte generation of the liverwort Marchantia polymorpha. We found that M. polymorpha possess the smallest known toolkit for the indole-3-pyruvic acid (IPyA) pathway in any land plant and that this auxin synthesis pathway mainly is active in meristematic regions of the thallus. Previously a Trp-independent auxin synthesis pathway has been suggested to produce a majority of IAA in bryophytes. Our results indicate that the Trp-dependent IPyA pathway produces IAA that is essential for proper development of the gametophyte thallus of M. polymorpha. Furthermore, we show that dormancy of gemmae is positively regulated by auxin synthesized by the IPyA pathway in the apex of the thallus. Our results indicate that auxin synthesis, transport, and signaling, in addition to its role in growth and development, have a critical role in regulation of gemmae dormancy in M. polymorpha.
© 2015 American Society of Plant Biologists. All rights reserved.
... While developing within the cup, gemmae are apolar with respect to their dorsiventral axis, and remain in stasis until displaced from the cup (Schröder 1886, Molisch 1922, Oppenheimer 1922, Tarén 1958). The cup acts as a splash cup aiding in the dispersal of gemmae by raindrops (Kny 1890, Brodie 1951, Equihua 1987. After displacement from the cup, dorsiventral differentiation depends upon the position of a gemma with respect to external environmental factors, the first of which was identified by Mirbel as light (Fig. 6). ...
While written accounts of plants date back thousands of years, due to the degradation of scientific literature during the dark ages descriptions descended from Greeks writings are sometimes equivocal as to species identity. Such is the case with Marchantia in the pre-Renaissance literature, however, indisputable illustrations of Marchantia polymorpha were made as early as the mid-15th century, beginning a rich historical literature on its taxonomy, development, and physiology. In this review I present three vignettes, each of which are themselves abbreviated due to space constraints. The first presents the role of Marchantia and related liverwort species in the discovery of sex in cryptogams, from the elucidation of liverwort life cycles the 18th century to the sequence of the Y chromosome in the 21st. A second vignette describes the use of Marchantia polymorpha as a model organism in the early 19th century debate concerning the cellular nature of organisms and the origin of new cells - an endeavor that provided us with Charles-François Brisseau de Mirbel's mémoire containing beautiful, if slightly fanciful, illustrations of the Marchantia life cycle. The final vignette chronicles the use of Marchantia polymorpha gemmae over the past two centuries to elucidate the mechanism by which a dorsiventral body plan is established from an initially apolar gemma. While only covering a fraction of the literature available, these vignettes provide a glimpse of historical and recent discoveries available upon which to build a molecular genetic and genomic understanding of Marchantia.
© The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
... Studies of other plant groups indicate dispersal of up to 1 m (Nakanishi 2002), although there are inevitably many variables (including plant height, seed weight, etc.) that affect potential dispersal distance; it is perhaps significant that the stem of T. hongkongensis elongates as the fruit matures (Fig. 3C), thereby possibly increasing seed dispersal distance. Brodie (1951) observed that seeds of species that are rain-splash dispersed are often coated with a hydrophilic colloid that rapidly absorbs water, and which may act as a lubricant, facilitating separation of seeds by rain drops. Thismia hongkongensis seeds are surrounded by a conspicuous mucilage-like substance (Fig. 3D) that may function in this way. ...
A new species, Thismia
hongkongensis S.S.Mar & R.M.K.Saunders, is described from Hong Kong. It is most closely related to Thismia
brunonis Griff. from Myanmar, but differs in the number of flowers per inflorescence, the colour of the perianth tube, the length of the filaments, and the shape of the stigma lobes. We also provide inferences on the pollination ecology and seed dispersal of the new species, based on field observations and interpretations of morphology. The flowers are visited by fungus gnats (Myctophilidae or Sciaridae) and scuttle flies (Phoridae), which are likely to enter the perianth tube via the annulus below the filiform tepal appendages, and exit via small apertures between the filaments of the pendent stamens. The flowers are inferred to be protandrous, and flies visiting late-anthetic (pistillate-phase) flowers are possibly trapped within the flower, increasing chances of pollen deposition on the receptive stigma. The seeds are likely to be dispersed by rain splash.
... liquid impacts | granular impact cratering | jamming | liquid marble G ranular impact cratering by liquid drops is likely familiar to all of us who have watched raindrops splashing in a backyard or on a beach. It is directly relevant to many important natural, agricultural, and industrial processes such as soil erosion (1,2), drip irrigation (3), dispersion of microorganisms in soil (4), and spray-coating of particles and powders. The vestige of raindrop imprints in fossilized granular media has even been used to infer air density on Earth 2.7 billion years ago (5). ...
When a granular material is impacted by a sphere, its surface deforms like a
liquid yet it preserves a circular crater like a solid. Although the mechanism
of granular impact cratering by solid spheres is well understood, our knowledge
on granular impact cratering by liquid drops is still very limited. Using
high-speed photography, we investigate liquid-drop impact dynamics on granular
media. Surprisingly, we find that granular impact cratering by liquid drops
follows the same energy scaling as that of asteroid impact cratering. Inspired
by this similarity, we develop a simple model that quantitatively describes the
observed crater morphologies. Our study sheds light on the mechanisms governing
raindrop impacts on granular surfaces and reveals an interesting analogy
between familiar phenomena of raining and catastrophic asteroid strikes.
... This dispersal strategy seems to be much more efficient than the splash-cup mechanism (described in detail by Brodie, 1951) in Cyathus species. The spores, which are enclosed in peridioles, are only released when rain drops strike the turbinate basidiomata (hydrochory). ...
Species composition and richness of epigeous gasteromycetes were investigated in four remnants of the Brazilian Atlantic Forest in northeastern Brazil. Two of these areas are coastal, lowland forests, while the other two, also known as ‘brejos de altitude’, are inland, highland forests. Thirty-six field expeditions were carried out from Jun. 2008 to May 2009 in a 500 m × 20 m transect in each surveyed area. Collected specimens consisted of 16 gasteroid species of the genera Clathrus (one sp.), Cyathus (four spp.), Geastrum (nine spp.), Morganella (one sp.) and Phallus (one sp.). Analysis of Similarity (ANOSIM) showed that species richness and composition of gasteroid fungi are different between lowland and highland forests. There was no significant difference between collecting seasons (dry and rainy months) in the four localities.
... These represent scyphulae in which gemmae have developed. These structures are splash cups that are the best-known method for vegetative dispersal , since they can disperse their carried contents up to 60 cm [3]. Gemmae cups of the studied material showed some differences in shape and size. ...
In the Oliete Sub-Basin, the Escucha Formation has been divided into three different lithologic intervals, from base to top: E1 (heterolithic with coal), E2 (mainly sandstones), and E3 (claystones). At the upper part of the interval E2, a grey-silty lithosome has been recognized, corresponding to a low-energy sedimentary environment related to a sandy shoal. In this lithosome, marchantiopsid-rich beds extending up to tens of square metres have been preserved. The plant association consists of well-developed mature gametophytes of complex thallose liverworts with thalli radial, dichotomous branched, rosette forming, prostrate and, in most cases, with gemmae cups located on their dorsal surface. The occurrence of scattered individuals forming distinct rosettes that, in many cases, are interlocked or interwoven and the loose arrangement of the association, along with sedimentological characteristics, allows us to interpret these liverworts-rich beds as monospecific colonization mats at early stages of colonization, in which marchantiopsids played the role of pioneers. In addition, the high proportion of gemmiferous individuals provides significant information on the environmental conditions and the effectiveness of colonization by asexual diaspores. Specimens have been assigned to family Marchantiaceae owing to their morphological features. Although liverworts colonization mats have been mentioned from the Albian of Antarctica, no fossil record of these existed at lower palaeolatitudes or in the Upper Aptian–Lower Albian. In addition, no previous record of clonal communities of plants derived from gemmae exists. Due to the latter, the occurrence of the studied colonization mats becomes of prime importance.
... The tradeoff is that a large number of spores derived from a single fruiting body are dispersed in close proximity, which is likely to facilitate inbreeding. Working to facilitate outcrossing, the sticking action of the hapteron allows peridioles to cling to vegetation for possible future ingestion and further dispersal by herbivores (Brodie, 1951). Evidence for this adaptation for herbivore dispersal can be seen with the species Cyathus stercoreus, by the fact it is primarily coprophilous and spores will not germinate until incubation at 40 1C for 48 h (Brodie, 1975). ...
Many organisms display codispersal of offspring, but fewer display codispersal of compatible gametes. This mechanism enhances the ability of a species to colonize after long distance dispersal as a mechanism of reproductive assurance, but it also fosters inbreeding and potential reduction in fitness. Here we investigated both long distance dispersal and inbreeding in the bird's nest fungus Cyathus stercoreus, a dung and mulch-associated fungus with a splash cup fruiting body appearing like a miniature bird's nest of 'eggs' or peridioles that contain thousands of mating compatible meiotic spores. To investigate the genetic structure in the species, six North American urban populations were hierarchically sampled and genotyped using 10 microsatellite markers. We detected significant levels of inbreeding through heterozygote deficiencies at four loci, with global F(IS)=0.061. Dispersal limitation was suggested by both spatial autocorrelation and the detection of population structure between Louisiana and Michigan using clustering and F-statistics. Although inbreeding may facilitate colonization by the fungus, it has a negative effect on the fitness of populations as estimated from a 15% reduction in growth rates of inbred strains relative to outcrossed. Mating tests revealed that C. stercoreus has a higher estimated number of mating-type alleles (MAT-A= 39, MAT-B= 24) than other species of bird's nest fungi, which would increase its outcrossing efficiency. We speculate that the increased number of mating-type alleles is the result of a recent range and population size expansion into urban environments.Heredity advance online publication, 21 November 2012; doi:10.1038/hdy.2012.95.
... One function suggested for the cup in sorediate lichens is dispersal of propagules by rainwater. This splash cup mechanism of dispersal is known to occur in plants (Brodie 1951;Nakanishi 2004), and it has also been described for sorediate dispersal in Cladonia chlorophaea (Bailey 1966). However, none of the cup forming species in this study produce propagules, eliminating sorediate dispersal as a possible function. ...
Members of the Cladonia gracilis group of lichen fungi are common terrestrial lichens where morphological features are more similar between members of the C. gracilis species complex and allied species outside the complex than they are between subspecies within the complex. The objectives of this study were to examine whether the Cladonia gracilis species complex is monophyletic, to determine whether morphological similarity is supported by genetic variation, and to examine the utility of the polyketide synthase (PKS) gene for phylogenetic studies among closely related species. Two loci, the ketosynthase region of the PKS gene and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA, were sequenced and analysed by Maximum Parsimony, Bayesian and haplotype network analyses. Functional differences were also inferred through ITS2 RNA secondary structures and non-synonymous changes in translated PKS amino acid sequences. The monophyly of the C. gracilis complex is supported by 71% bootstrap in the ITS phylogeny, and 92% bootstrap with greater than 95% posterior probability in the PKS phylogeny. Morphological similarity is not always supported by genetic similarity. The PKS gene is less variable than the ITS but the PKS supports species hypotheses that are reflected in the ITS2 RNA model. We conclude that monophyly of the C. gracilis complex can be supported if C. cornuta, C. coniocraea and C. ochrochlora are included in the complex. In addition, C. maxima, C. phyllophora and C. subchordalis are supported as monophyletic species outside the C. gracilis complex. Cladonia maxima may form a separate species and variation among podetial morphology may be explained by convergent evolution.
... In drying material it was also observed that hymenia, hyphophores and parts of campylidia were eaten by insects (Psocoptera), which may play a role for dispersal in nature. If rainwater is considered as the principal agent, the dispersal method might be similar to the splash-cup mechanism (Brodie 1951;cf. Lucking 1994). ...
The taxonomy of the foliicolous members of Arthoniaceae (Anhonia, Arthothelium, Cryptothecia, Eremothecella) in Costa Rica is revised. Cryptothecia farkasiae sp. nov. is described, being closely related to Stirtonia sprucei, and bearing pycnidia reminiscent of Eremothecella. Anhonia lividofusca is placed in synonymy with A. aciniformis. Pycnidia and pycnospores are further described for Anhonialeptosperma, A. cyanea, A. palmulacea, A. trilocularis, Anhothelium cingulatum, Stinonia sprucei and S. macrocephala, and campylidia were found on thalli of Anhonia aciniformis. Anhonia nigratula and Cryptothecia Candida are reported for the first time from Costa Rica, and new localities are given for previously reported species. Ecological data are provided, and the relationships between foliicolous members of the Arthoniaceae are discussed.
... Some fruiting bodies e.g. splashcups of the bird's nest fungus (Cyathus olla) are especially adapted to utilise the force of falling raindrops to dislodge spores (Brodie, 1951). ...
Thesis (MSc)--University of Stellenbosch, 2006. Bibliography.
This chapter contains detailed information on life cycle, morphology and classification of the three divisions of Bryophytes: Marchantiophyta (liverworts), Bryophyta (mosses) and Anthocerotophyta (hornworts). Additional sections cover the importance of asexual reproduction in Bryophytes, central aspects of their physiology and physiological ecology and the essentials of Bryophyte ecology (autecology, population/community ecology and systems ecology).
If human population growth is not controlled, natural areas must be sacrificed. An alternative is to create more habitat, terraforming Mars. However, this requires establishment of essential, ecosystem services on a planet currently unamenable to Terran species. Shorter term, assembling Terran-type ecosystems within contained environments is conceivable if mutually supportive species complements are determined. Accepting this, an assemblage of organisms that might form an early, forest environment is proposed, with rationale for its selection. A case is made for developing a contained facsimile, old growth forest on Mars, providing an oasis, proffering vital ecosystem functions (a forest bubble). It would serve as an extraterrestrial nature reserve (ETNR), psychological refuge and utilitarian botanic garden, supporting species of value to colonists for secondary metabolites (vitamins, flavours, perfumes, medicines, colours and mood enhancers). The design presented includes organisms that might tolerate local environmental variance and be assembled into a novel, bioregenerative forest ecosystem. This would differ from Earthly forests due to potential impact of local abiotic parameters on ecosystem functions, but it is argued that biotic support for space travel and colonization requires such developments. Consideration of the necessary species complement of an ETNR supports a view that it is not humanity alone that is reaching out to space, it is life, with all its diverse capabilities for colonization and establishment. Humans cannot, and will not, explore space alone because they did not evolve in isolation, being shaped over aeons by other species. Space will be travelled by a mutually supportive system of Terran organisms amongst which humans fit, exchanging metabolites and products of photosynthesis as they have always done.
We investigate the dynamics of drop impacts on dry solid surfaces. By synchronising high-speed photography with fast force sensing, we simultaneously measure the temporal evolution of the shape and impact force of impacting drops over a wide range of Reynolds numbers ( ). At high , when inertia dominates the impact processes, we show that the early time evolution of impact force follows a square-root scaling, quantitatively agreeing with a recent self-similar theory. This observation provides direct experimental evidence on the existence of upward propagating self-similar pressure fields during the initial impact of liquid drops at high . When viscous forces gradually set in with decreasing , we analyse the early time scaling of the impact force of viscous drops using a perturbation method. The analysis quantitatively matches our experiments and successfully predicts the trends of the maximum impact force and the associated peak time with decreasing . Furthermore, we discuss the influence of viscoelasticity on the temporal signature of impact forces. Last but not least, we also investigate the spreading of liquid drops at high following the initial impact. Particularly, we find an exact parameter-free self-similar solution for the inertia-driven drop spreading, which quantitatively predicts the height of spreading drops at high . The limit of the self-similar approach for drop spreading is also discussed. As such, our study provides a quantitative understanding of the temporal evolution of impact forces across the inertial, viscous and viscoelastic regimes and sheds new light on the self-similar dynamics of drop-impact processes.
This paper discusses the splash-cup dispersa! of gemmae in Marchantia polymorpha L. Experimental results indicate that gemmae may be thrown to distances of up to 120 cm from the parent plant. Splash-cup dispersa! allows the immediate occupation of nearby habitats and supplements spore dispersa! on a local scale. The world wide distribution of M. polymorpha is partly dueto the effectiveness of these reproductive systems.
Premise of the study:
Some common leaf-dwelling lichen fungi produce asexual spores (conidia) within curved, dorsiventral structures called campylidia. Their shape and tendency to face in the same direction have generated speculation about how dispersal is accomplished. Here we tested the hypothesis that campylidia orient their spore-producing surface against runoff currents and examined the effects of hydration to better understand the spore dispersal mechanism.
Methods:
Palm leaves bearing lichens (Calopadia) were surveyed with a dissecting microscope for campylidia with fibrous debris entangled around the base. Where possible, the direction of runoff flow was inferred from the position of the entangled debris; the angle between this direction and that toward which the spore-producing side faced was calculated for 67 campylidia. Other fresh-collected campylidia were photographed in the air-dry state and again after hydration.
Key results:
Orientation of campylidia was strongly correlated with direction of runoff flow, such that the spore-producing side faced against oncoming runoff. Hydration of campylidia quickly resulted in swelling of the conidial mass beneath a thin flap of tissue covering the conidiogenous surface. The flap then bulged outward, exposing the conidial mass from above within its pocket-like compartment.
Conclusions:
Our results support previous contentions that water impact against campylidia is important in spore dispersal. However, the morphology of hydrated campylidia and their strong tendency to face upstream suggest that water currents impact laterally upon the thin tissue covering the hydrated conidial mass, thereby extruding spores apically. We contrast these findings with previous suggestions that campylidia act as splash cups.
Scutellaria drummondii var. edwardsiana (Drummond's skullcap) and S. wrightii (Wright's skullcap) use hydroballochory to disperse nutlets following rains. The nutlets form in a fruiting calyx called a scutellum that expands in size and changes in color from green to yellow and finally brown. The scutellum has a cup-shaped upper portion and a scale-like lower portion. When a drop of rain hits the cup-shaped top of a yellow or brown scutellum, it dehisces and falls off the plant and the resulting mechanical energy from this event causes the scales to throw the nutlets away from the plant. Based on field and greenhouse experiments scutella were observed to disperse following precipitation events.
Splashes of water drops on liquid surfaces are important phenomena in
several fields, notably the geosciences where they determine some
transport rates and atmospheric-electrification processes. Splashes on
smooth liquid surfaces have been well described, but in actual field
situations splashes usually occur on disturbed surfaces. This report
describes two new types of splashes that occur in the presence of
surface waves. These were studied with drops falling from a buret into
the center of a circular battery jar filled with water. Each drop
interacted with the reflected waves produced by the preceding drops. We
find that a drop impacting near the time of a crest of the surface wave
produces intense surface waves and a diminutive Rayleigh jet. A drop
impacting near the time of a trough of the surface wave produces weak
surface waves but an unusually high Rayleigh jet. The great difference
in these two types of interactions implies that any study of
transportation or electrification due to splashes must include drop
surface-wave effects.
Communication in interdisciplinary research ranges from communication between collaborators with different interests and vocabularies,
through presenting published conclusions in a form comprehensible to all potential users, to choice of a publication vehicle
and facilitating information retrieval.
Two species of Aleurodiscus occurring on conifers, which have been under observation for several years, are described as new. Both are related to Aleurodiscus roseus (Pers. ex Fr.) Höhn. & Litsch. The first, described as A. Minnsiae sp. nov., occurs most commonly on Tsuga canadensis and is noteworthy because of an associated sclerotial disseminating phase of characteristic morphology, which has been known under the herbarium name Minnsia carnea E. & E. ined. The history of our knowledge of this phase is given in some detail. The second species occurs on Pinus Strobus and is described as A. Pini sp. nov. The known collections of both species are listed. Comparative culture work was conducted which showed that the two species are heterothallic, have a different growth rate, and are incompatible. They are also different from a form of A. roseus occurring on Populus which proved to be homothallic.
The splash-cups of the bird" nest fungi, li and mosses
- A M Bollew
BOLLEW, A. M. W * The splash-cups of the bird" nest fungi, li and mosses. (AbsPrwt.) Trans, Roy. SOC. Can. 1111, 36 :159. f942.
Botany, an evolutionay apprmch. The BlaEstan Company
- W D Gma~s
GMA~S, W. D. Botany, an evolutionay apprmch. The BlaEstan Company, Philadelphia, 1950.
Downloaded from www.nrcresearchpress.com by Duke University on 11/22/12 For personal use only. References 1. BROB~E, H. J. Tebraplarity and unijaferal diploidizatisn in the bid's nest fuagus Cyathgs sJercoreas
- Canadian Journal
- Botany
CANADIAN JOURNAL OF BOTANY. VOL. 29 Can. J. Bot. Downloaded from www.nrcresearchpress.com by Duke University on 11/22/12 For personal use only. References 1. BROB~E, H. J. Tebraplarity and unijaferal diploidizatisn in the bid's nest fuagus Cyathgs sJercoreas. Am. J. Ba%tany-, 35 : 312-320. 1948.
The form of the wridium, the fate of the pridiola, and the function of the funicullw cords in the Nidulariaceae (Bird's Nest Fungi). Unpublished abstract
- A H B~ler
B~LER, A. H, R. The form of the wridium, the fate of the pridiola, and the function of the funicullw cords in the Nidulariaceae (Bird's Nest Fungi). Unpublished abstract. Ann. Rept. NatE. Acad. %i. US. k94%42. p 4.
Egg-throwers of the marshrmrn world, 1. N.Y. Botan. Garden
- Carol Lfpoo~wa~~
LFPOO~WA~~, CAROL H H Egg-throwers of the marshrmrn world, 1. N.Y. Botan. Garden, 44:274-278. 8943. Can. J. Bot. Downloaded from www.nrcresearchpress.com by Duke University on 11/22/12 For personal use only.
Studies on Canadian TheIehoraceae. V. Two new species of Akrrro-dis~ur on conifers
- H S Jackson
JACKSON, H. S. Studies on Canadian TheIehoraceae. V. Two new species of Akrrro-dis~ur on conifers. Can. J. Re~earch, 8, 28 :63-77. 1950.
Basidia and spora of the Nidulafiacem
- C Artenen
- Iv
ARTENEN, C. IV. Basidia and spora of the Nidulafiacem, Myc01ea, f9 :239-247. 6927.
Recherche5 sue f'organization et le mode de fructifica-tion des champignabas de la tribu des Nidu
- L R Tulasne
- C T~asxe
TULASNE, L. R. and T~ASXE, C. Recherche5 sue f'organization et le mode de fructifica-tion des champignabas de la tribu des Nidu'Bari&. Ann. &i. Nat. Botan. 3 : 41-107. 18-$4
YzAation in fruit bodies of Cyathgs skrc~ras prduced in culture. %ycdogia
- H J Brobie
BROBIE, H. J. YzAation in fruit bodies of Cyathgs skrc~ras prduced in culture. %ycdogia, 40 : 014626. 6948.
Tebraplarity and unijaferal diploidizatisn in the bid's nest fuagus Cyathgs sJercoreas
BROB~E, H. J. Tebraplarity and unijaferal diploidizatisn in the bid's nest fuagus
Cyathgs sJercoreas. Am. J. Ba%tany-, 35 : 312-320. 1948.
Downloaded from www.nrcresearchpress.com by Shanghai International Studies University on 06
- J Can
- Bot
Can. J. Bot. Downloaded from www.nrcresearchpress.com by Shanghai International Studies University on 06/06/13
For personal use only.