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Dioon caputoi (Zamiaceae), a New Species from Mexico
Abstract
A new species ofDioon (D. caputoi), found in Puebla, Mexico, is characterized by narrow leaflets, arising at an acute angle from the rachis and regularly and
widely spaced along it. This species has hitherto been confused withD. purpusii.
... Many Dioon species from Oaxaca were described in the late 1970s or early 1980s thanks to the efforts of the Mexican botanist Mario Vázquez-Torres and the Italian botanists Paolo De Luca, Aldo Moretti, and Sergio Sabato (e.g., De Luca et al. 1980a, 1980b, 1981. These authors contributed enormously to the delineation of the geographic ranges and species delimitations. ...
Dioon oaxacensis sp. nov. (Zamiaceae), a new cycad species from Oaxaca, Mexico, is described. The morphological traits of the new taxon are compared with its sister species, D. merolae. The species delimitation between the two species is consistent with previously published genetic evidence. Dioon oaxacensis can be easily identified by its flat, stiff, straight leaflets obliquely inserted to rachis, and by its large reproductive structures. Populations of D. oaxacensis usually occur in dry habitats, growing on rocky hillsides, and co-habiting with plants well recognized to be adapted to aridity.
... Williams. The delimitation of these species has been largely based on macromorphological studies (Lindley, 1843;Rose, 1909;De Luca and Sabato, 1979;De Luca et al., 1978, 1980a, 1980b, 1981a, 1981b, 1984Gregory et al., 2003), but anatomical characters have received little attention. Molecular phylogenetic studies of the genus (Moretti et al., 1993;González et al., 2008;Gutiérrez-Ortega et al., 2017) generally agree upon two major clades for the genus, which have diversified during successions of dispersal and vicariance events that occurred during the early and mid Cenozoic (Moretti et al., 1993), followed by recent speciation events that produced the modern taxa (Moretti et al., 1993;González et al., 2008;Nagalingum et al., 2011;Gutiérrez-Ortega et al., 2017). ...
Anatomical descriptions can be effective for solving systematic issues, but these studies are relatively scarce for cycads. Therefore, we present here a leaflet and cuticle anatomical study on the genus Dioon, to provide a set of epidermal traits that clarify species delimitation and relationships between species and their habitats. We used standard micro-technique for leaflet sectioning, and cuticular peel preparation for light microscopy. Also, we used the chromium trioxide method for scanning electron microscope observations on cuticles. Measurements were taken on 10 randomly chosen replicates of each cell or tissue type, for each of the leaflets sampled per taxon. Micromorphological variation among species was calculated for each trait. Finally, we reconstructed the ancestral states of the observed epidermal fibre-like cell and pore shapes, by tracing the characters on the species phylogenetic tree of Dioon. We were able to describe the leaflet anatomy, cuticles, and epidermal features for 14 Dioon species. The quantitative analysis was useful to reveal five geographically structured species groups. Character tracing on the phylogenetic tree of Dioon has amplified our current understanding on species relationships with respect to habitats. The presence/absence data suggest that the evolutionary acquisition-deletion of structural shapes is phylogenetically independent, thus climate seems to play a very important role in the variation of cuticular and stomatal traits. Many epidermal traits, especially adaxial cuticle thickness and epistomatal pore width and depth, might be adaptations resulting from a long-term influence of climate, since they appear to have correlation with climatic conditions in relation to their biogeography. We conclude that the variation of all traits are mostly sustained and intrinsic to the species, and are of promising taxonomic value. The combination of the epidermal traits with other characters has potential for taxonomic resolution at species level.
... The collector of the type series is C. A. Purpus, a German plant collector who spent the years 1907-8 in Mexico around San Luís Tultitlanapa (now San Luís Atolotitlán), a locality south of Tehuacán especially rich with cactus. During this period he collected herbarium specimens of one species of Dioon (currently recognized as D. caputoi), which were deposited in at least 13 herbaria (De Luca et al. 1980). A Purpus photograph of a Dioon from this period (see Schneckenburger 2001) is clearly identifiable as D. caputoi. ...
The taxonomy of the weevils inhabiting male cycad cones in the New World is reviewed. All species belong in a single subtribe, Allocorynina, of the family Belidae, subfamily Oxycoryninae and tribe Oxycorynini and are known to develop only in cones of the cycad genera Dioon and Zamia. Most species of Rhopalotria Chevrolat develop in male cones of Zamia ranging from Mexico, Belize, the Caribbean (Cuba, Isle of Youth, Cayman Islands, Jamaica and the Bahamas) to southern Florida, and one species in those of Dioon spinulosum in Mexico. Rhopalotria consists of three previously described species, two previously described genus-group names (treated herein as subgenera) and four new species described herein: subgenus Allocorynus Sharp with R. calonjei n. sp., R. furfuracea n. sp., R. mollis (Sharp) and R. vovidesi n. sp., and the nominate subgenus Rhopalotria with R. dimidiata Chevrolat, R. meerowi n. sp. and R. slossoni (Schaeffer). The species of Parallocorynus Voss develop only in cones of Dioon in Mexico, and the genus consists of one previously described species, the nominate subgenus and three new subgenera and 11 new species described herein: subgenus Dysicorynus n. subg. with P. andrewsi n. sp. and P. sonorensis n. sp., subgenus Eocorynus n. subg. with P. chemnicki n. sp. and P. schiblii n. sp., subgenus Neocorynus n. subg. with P. iglesiasi n. sp. and P. inexpectatus n. sp., and the nominate subgenus Parallocorynus with P. bicolor (Voss), P. gregoryi n. sp., P. jonesi n. sp., P. norstogi n. sp., P. perezfarrerai n. sp. and P. salasae n. sp. Two new genera are described, Protocorynus with one new species in Honduras, P. bontai, and Notorhopalotria with four new species ranging from Costa Rica to Colombia, N. montgomeryensis, N. panamensis, N. platysoma and N. taylori. Keys to genera, subgenera and species are provided. All of these weevils are believed to be involved in pollination of their host cycads.
... The collector of the type series is C. A. Purpus, a German plant collector who spent the years 1907-8 in Mexico around San Luís Tultitlanapa (now San Luís Atolotitlán), a locality south of Tehuacán especially rich with cactus. During this period he collected herbarium specimens of one species of Dioon (currently recognized as D. caputoi), which were deposited in at least 13 herbaria (De Luca et al. 1980). A Purpus photograph of a Dioon from this period (see Schneckenburger 2001) is clearly identifiable as D. caputoi. ...
... E-mail: tim@gene.com Luca and Sabato (De Luca, Sabato & Vázquez Torres, 1979a) from the eastern Tehuacan valley; D. caputoi De Luca, Sabato and Vázquez Torres (De Luca, Sabato & Vázquez Torres, 1980a) from the high desert south of Tehuacan; and D. rzedowskii De Luca, Moretti, Sabato and Vázquez Torres (De Luca et al., 1980b) from the canyon of the Rio Santo Domingo. Dioon rzedowskii is closely related to D. spinulosum Dyer (Dyer, 1883), a lowland species occurring downstream in the Rio Santo Domingo drainage. ...
Dioon argenteum sp. nov. (Zamiaceae) is described from northern Oaxaca, México. Flat leaves, and persistently tomentose, slightly imbricate leaflets with marginal prickles characterize this species. The specific epithet argenteum was chosen to describe the silver appearance of the persistent tomentum covering the new leaves. D. argenteum appears to have affinities with D. purpusii and D. califanoi. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 141, 471–476.
The cycad genus Dioon comprises 17 species from Mexico and Honduras, all of them delimited based on their morphological variation and geographic distribution. A recent evaluation of the biological variation among Dioon populations from Oaxaca and Chiapas, Mexico, demonstrated that the concept of the species Dioon merolae actually consists of three lineages that should be recognized as different taxa. One lineage was already described as Dioon oaxacensis, leaving the concept of Dioon merolae comprising two lineages distributed on both sides of the Isthmus of Tehuantepec. However, there are conspicuous morphological differences between these two lineages. Here, we tested whether such a differentiation within the concept of Dioon merolae merits the differentiation of two different taxa. We evaluated the qualitative and morphometric variation among populations belonging to the Dioon merolae lineages, and compared it with the closely related species Dioon oaxacensis. Morphological observations and statistical tests demonstrated that the populations of southeastern Oax-aca, traditionally considered as part of Dioon merolae, represent a distinct species that we described as Dioon salas-morale-sae. Identifying the diagnostic characters of this new species helps enable an understanding of the criteria that should be considered to delineate the boundaries between other cycad species.
Cycads are a group of plants in the order Cycadales, comprising ten genera, and with a worldwide distribution. Very few taxonomic revisions are available for the genera in this order, and the present one is intended to provide a revision of the current knowledge in the genus Dioon. The revision was based on bibliographic research and analysis of herbarium specimens, including live specimens found in different botanical gardens and greenhouses. Sixteen species are recognized for the genus. This study includes morphological descriptions, maps with species distribution, line drawings of diagnostic characters, and a key to the species. Detailed taxonomic notes for each species, as well as information on their distribution and habitat is provided, including the uses and common names when available. Fifteen of the total species are distributed in Mexico and one species is found in the border of Honduras and Nicaragua. Therefore, the genus is endemic to Megamexico II.
Population structure, leaf phenology and leaf turnover were followed over a 29-month period in Zamia debilis L.f. ex Aiton (Zamiaceae), an understory species in the Cambalache Forest in northern Puerto Rico. It was not possible to determine plant age or to measure the subterranean stems; size classes based on leaf number and leaf × leaflet number indices were used to determine population structure. Despite seasonal and year to year fluctuations in leaf number at the individual and population level, population profiles remained relatively constant. At any one time, over 50% of the population was composed of unbranched individuals with one or two leaves. Only 7% of the plants were branched. Plants with seven or more leaves comprised at a maximum 8% of the population, but accounted for 28% of the total foliage. Size classes based on leaf number and on a leaf × leaflet index gave approximately reverse J-shaped curves typical of trees with shade tolerant seedlings and saplings. New leaves emerged throughout the year, with a peak at the beginning of the rainy season in May or June and lowest production during the dry months of February through April. Average leaf life expectancy was approximately 2.3 years. Leaf death occurred over an extended period of time by the loss of individual leaflets. Patterns in leaf production and loss differed between few- and many-leaved plants. On the average, as the number of mature leaves on a plant increased, time between emergence of new leaves decreased. In many-leaved plants more than one event of new leaf emergence per year was common. Individuals with one to three mature leaves and individuals with four or more mature leaves differed in their response to water stress: few-leaved plants generally reduced the rate of new leaf production and retained old leaves longer. Plants with more than three leaves continued to produce new leaves, but the rate of leaf mortality increased so that most had a net leaf loss. There was no evidence that leaf emergence or retention were affected by cone production or seed maturation.
A phylogenetic analysis of all the intrageneric taxa of the genus Dioon Lindley (Zamiaceae) was undertaken by using chloroplast DNA restriction fragment length polymorphism analysis. Wagner parsimony analysis on a 187 character matrix yielded two equally parsimonious trees, differing only for the position of D. caputoi. The consensus tree has two well-defined major clades. The first is composed of D. mejiae, D. rzedowskii, and D. spinulosum; the second is composed of D. califanoi, D. caputoi, D. edule var. angustifolium, D. edule var. edule, D. holmgrenii, D. merolae, D. purpusii, D. tomasellii var. sonorense, and D. tomasellii var. tomasellii. A phenetic analysis of the same data showed results broadly congruent with the cladistic analysis. This resulting phylogeny is partially congruent with morphological data and is also compatible with the biogeography of the genus. Modem species of Dioon may have evolved as a consequence of a very fast succession of vicariance events that mainly occurred during the early Cenozoic. The short time between each of these events may not have allowed the accumulation of a large number of morphological synapomorphies for the groups of species.
The cycad Zamia pumila L. was examined for differences in leaflet morphology between sun and shade plants and between males and females within a single population in northern Puerto Rico. Sun leaflets are significantly smaller than shade leaflets in length, width, and surface area; and sun leaflets have a higher length: width ratio than shade leaflets. Also, average densitythickness is greater for sun leaflets than for shade leaflets. Males and females are similar in leaflet size; but the females had a larger number of leaflets per leaf than males.
Distribution, ecology, and morphology of the species of Dion are presented. The genus Dion is distributed in Mexico and in Honduras, where it is generally scattered and restricted to rocky, steep habitats.
On the basis mainly of the morphology of the seeds, of the seedlings, and of the female cones, three natural groups were recognized. The first group, which is the most distinct morphologically, is made up of D. mejiae endemic to Honduras. The second group is made up of D. spinulosum and D. rzedowskii , whose distribution is restricted to a very small area in Mexico. They appear to be the only Dion spp. to be adapted to moist and shaded habitats. The third group is made up of the remaining spp. of Dion , all Mexican in distribution. They appear to be well adapted to open and dry habitats generally. Stems, female cones, and seeds show the trends to decreasing size from south to north in this group.
A key of the genus is given.
Dentro de los grupos actuales de espermatofitas, plantas con semilla, las cícadas cuentan con el registro fósil más antiguo. A pesar de ello, su estatus como “fósiles vivientes” ha sido puesto en entredicho recientemente con base en resultados de estudios filogenéticos moleculares. El grupo presenta apomorfías morfológicas vegetativas y posiblemente también reproductivas, siendo Cycas el género más divergente. Junto con Australia y Sudáfrica, México es uno de los 3 centros de diversidad del orden Cycadales, con 54 especies pertenecientes a 3 de los géneros que constituyen la familia Zamiaceae: Ceratozamia, Dioon y Zamia. En este sentido, México es la región más diversa y con el mayor número de endemismos (88.9%) de la familia Zamiaceae en el Neotrópico. En general, el estado de conservación de los 3 géneros es crítico, debido a lo cual, todas las especies de cícadas mexicanas se encuentran bajo alguna categoría de riesgo, de acuerdo con la Nom-059-Semarnat-2010. Finalmente, consideramos que el conocimiento generado hasta el momento sobre las cícadas en nuestro país, en términos de sistemática, biología evolutiva y conservación, nos permitirá esclarecer diferentes escenarios evolutivos, principalmente aquellos relacionados con los procesos y los patrones que han determinado su diversidad actual.
All valid combinations in the genera Ceratozamia, Dion, and Microcycas are presented. The holotypes are identified, and, in those cases where no holotype has been found, a lectotype or neotype is designated.
Cycadean leaves from the Palaeogene Noda Group of Northeast Japan are characterised by entire, wavy, or spinose pinne and have dichotomy forked open veins with occasional anastomoses. The guard cells are sunken and overarched by a cuticular flange which protrudes from the outer surface of the encircling cells. The form of the leaves resembles that of extant Dioon spinulosum Dyer, which is now native in Mexico. However, the stomatal complex in the fossil lacks the intercalated cells which are characteristic of several other extant cycad species as well as Dioon spinulosum. The cuticular features of our leaves have many characters shared also with certain species of Mesozoic Ctenis and Pseudoctenis. The name Dioonopis nipponica gen. et sp. nov. is proposed to accommdate these leaves, which enhance our knowledge of phylogenetic relationships between Mesozoic and extant cycads.
Zamia debilis is an understory species in the Cambalache Forest, N Puerto Rico. Sizes classes based on leaf number and leaf × leaflet number indices were used to determine population structure. Despite seasonal and year to year fluctuations in leaf number at the individual and population level, population profiles remained relatively constant. At any one time >50% of the population was composed of unbranced individuals with 1-2 leaves. Only 7% of the plants were branched. Plants with ≥7 leaves comprised at a maximum 8% of the population, but accounted for 28% of the total foliage. Size classes gave approximately reverse J-shaped curves typical of trees with shade tolerant seedlings and saplings. New leaves emerged throughout the year, with a peak at the beginning of the rainy season in May or June and lowest production during the dry months of February through April. Average leaf life expectancy was c2.3 yr. Leaf death occurred over an extended period of time by the loss of individual leaflets. As the number of mature leaves on a plant increased, time between emergence of new leaves generally decreased. In many-leaved plants more than one event of new leaf emergence per year was common. Few-leaved plants generally reduced the rate of new leaf production and retained old leaves longer. Plants with >3 leaves continued to produce new leaves, but the rate of leaf mortality increased so that most had a net leaf loss. There was no evidence that leaf emergence or retention were affected by cone production or seed maturation. -from Authors
The holotype and additional specimens of cycadalean foliage known as Encephalartos gorceixianus Saporta from the Lower Miocene of Greece show strong gross morphological similarities to the extant genus Dioon Lindl. (Mexico, Honduras, Nicaragua) as well as the fossil Dioonopsis Horiuchi & Kimura (Palaeogene of Japan, and Alaska), rather than to the African genus Encephalartos Lehm. Because of the lack of the epidermis structure, its generic assignment must remain open. The occurrence of this relict in the Lower Miocene of southern Europe suggests palaeofloristic connections with other parts of the Northern Hemisphere, rather than with Africa.Revision des Cycadeen-Blattes „Encephalartos” gorceixianus Saporta (Zamiaceae) aus dem Untermiozän von Griechenland (Insel Euboea)Der Holotypus und weitere Exemplare einer Cycadeen-Beblätterung von Encephalartos gorceixianus Saporta aus dem Untermiozän Griechenlands zeigen größere morphologische Ähnlichkeiten zur rezenten Gattung Dioon Lindl. (Mexiko, Honduras, Nikaragua) und zu dem fossilen Dioonopsis Horiuchi & Kimura (Paläogen Japans und Alaskas) als zur rezenten afrikanischen Gattung Encephalartos Lehm. Wegen des Fehlens von Epidemisstrukturen muss ihre generische Einstufung offen bleiben. Das Vorkommen dieses Reliktes im Untermiozän von Südeuropa deutet eher auf paläofloristische Beziehungen zu anderen Teilen der Nordhemisphäre als zu Afrika hin.
The new species Dioon stevensonii, from the Rio Balsas basin spanning the states of Michoacan and Guerrero, Mexico, is described and illustrated. The description of this species implies a recircumscription of the populations of Dioon that constitute the previously characterised D. tomasellii, which also includes populations located in Durango, Nayarit and Jalisco. Dioon stevensonii differs from its congeners in characters of both vegetative and reproductive structures ‐ namely, leaflet contour shape, leaflet curvature and reflection of the megasporophyll tips. Despite its morphological affinities with D. tomasellii, complementary cladistic analyses of molecular matrices indicate that D. stevensonii has closer phylogenetic affinities with the D. edule and D. spinulosum species groups, which are distributed along the Gulf of Mexico and Caribbean seaboards. The proposal of D. stevensonii rests on the reevaluation of overlooked differences in morphological character states in herbarium material, corresponding to populations previously identified as D. tomasellii, which were confirmed after ex profeso field collections. The fact that such re‐evaluation was prompted by a hypothesis of relationships based on molecular data for the entire genus Dioon, establishes the proposal of D. stevensonii as an unusual case of reciprocal illumination, where the morphological evidence provided confirmation of a molecular hypothesis, and not vice versa.
A phylogenetic analysis of all the intrageneric taxa of the genus Dioon Lindley (Zamiaceae) was undertaken by using chloroplast DNA restriction fragment length polymorphism analysis. Wagner parsimony analysis on a 187 character matrix yielded two equally parsimonious trees, differing only for the position of D. caputoi. The consensus tree has two well-defined major clades. The first is composed of D. mejiae, D. rzedowskii, and D. spinulosum; the second is composed of D. califanoi, D. caputoi, D. edule var. angustifolium, D. edule var. edule, D. holmgrenii, D. merolae, D. purpusii, D. tomasellii var. sonorense, and D. tomasellii var. tomasellii. A phenetic analysis of the same data showed results broadly congruent with the cladistic analysis. This resulting phylogeny is partially congruent with morphological data and is also compatible with the biogeography of the genus. Modem species of Dioon may have evolved as a consequence of a very fast succession of vicariance events that mainly occurred during the early Cenozoic. The short time between each of these events may not have allowed the accumulation of a large number of morphological synapomorphies for the groups of species.
A new species ofDioon (Dioon holmgrenii), found on the Pacific slope of southern Oa xaca, is characterized by leaflets which are spinulose especially on the upper
margin, elongate and narrow. Distribution and ecology of OaxacanDioon species are reported.
A new species ofDioon found in northwestern Chiapas is characterized by linear-lanceolate leaflets arising at an acute angle from the rachis, obliquely
inserted on it and imbricate.
Dioon merolae De Luca, Sabato et Vázq.Torres, una especie de cícada de Chiapas conocida localmente como espadaña, juega un papel importante durante la festividad de la Santa Cruz del 3 de mayo entre la comunidad de Suchiapa de la Depresión Central del estado de Chiapas. Aparentemente ésta es una tradición nativa chiapaneca de origen prehispánico que se sincretizó con la religión católica durante la época colonial. Sus hojas se usan para adornar altares cada mayo durante esta festividad religiosa Católica. Las cícadas no parecen sufrir daño alguno por la poda anual de las hojas, pero la amenaza actual a las poblaciones y a esta tradición milenaria viene de activistas de otras tradiciones religiosas que provocan incendios al hábitat de la cícada durante el período del estiaje antes de la cosecha de las hojas.
A new Mexican species ofDioon has been found in Oaxaca,Dioon califanoi, characterized by keeled fronds and leaflets inserted obliquely above the rachis. A key to the known species ofDioon is given.
Contributions from United States National herbarium, vol. v. published by U. S. Dept of agriculture, Division of botany vol. VIII, X, XII, XIII by Smithsonian institution, United States National museum "Ferns collected in Mexico by J. N. Rose during the months of August and September 1897. By George E. Davenport" vol. v, p. 146-151
Dioon purpusii Rose, a misknown species of Zamiaceae
- M Vfizquez
& M. Vfizquez Torres. 1979. Dioon purpusii Rose, a misknown species of Zamiaceae. Delpinoa n.s. 20: 3t-35.
DIOON CAPUTOI 45 FIG. 4. Dioon caputoi. A. Megasporangiate cone
- De Luca
- Al @bullet
- B Megasporophyll
- bullet
DE LUCA ET AL.; DIOON CAPUTOI 45 FIG. 4. Dioon caputoi. A. Megasporangiate cone, @BULLET B. Megasporophyll, @BULLET C. Microspo-rophylls, @BULLET D. Seeds, @BULLET 31: 170-173.