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Six new Pavetta (Rubiaceae), including three ‘litter-bin’ species from the evergreen forests of Western Africa
Abstract
Six new species of Pavetta L. are described from the Wet Evergreen forests of Ghana, Ivory Coast and Liberia: Pavetta sonjae, P. bomiensis, P. abujuamii, P. ankasensis, P. quasidigita and P. sapoensis, the first of these with ornamental potential. The last three are considered ‘litter-bin’ species, a morphological syndrome whereby forest understorey plants accumulate litter in their leaf axils. Certain venation patterns are defined precisely and used to delimit species. The six new species are illustrated, compared with similar species and their conservation status is evaluated.
... Shortly thereafter, the phenomenon was described by Ng (1980) in plants from Malaysia. Despite de Granville's and Ng's insights, many field workers still view trapped litter masses as annoying detritus that has to be cleared away before a plant (Bernal & Balslev, 1996; Humilectic plants (Dressler, 1981) Humus-collecting plants (Copeland, 1907;Hennipman, Veldhoen & Kramer, 1990;Janssen & Schneider, 2005;Hübner, 2013) Litter-collecting plants (Weissenhofer et al., 2008;Lachenaud & Jongkind, 2013) Litter-gathering plants (Cheek, Horwath & Haynes, 2008;Lachenaud & Jongkind, 2013) Litter-trapping plants (Ng, 1980; 2008) Litterbin plants (Hawthorne, 2013;Lachenaud & Jongkind, 2013) Nest-epiphytes* (Schimper, 1903) Tank-epiphytes* (Schimper, 1903) Trash-basket plants (Dressler, 1981;de Nevers, 1995;Freiberg, 1999;Gibernau et al., 2007) *Applied only to epiphytic plants. 556 S. ZONA and M. J. M. CHRISTENHUSZ specimen can be collected or photographed. ...
... & N.W.Uhl of Mada- Allexis cauliflora (Oliv.) Pierre Schopfbaum GHA, CMN, GAB Kenfack et al., 2007;Hawthorne, 2013 gascar (and to a lesser extent, its congener M. insignis Humbert, species of Masoala Jum. and Ravenea dransfieldii Beentje), the petiole bases impound a considerable quantity of fetid water and rotting debris into which the palms may send adventitious roots (Dransfield & Beentje, 1995). In many respects, these species of palm are analogous to phytotelmforming bromeliads. ...
Litter-trapping plants have specialized growth habits and morphologies that enable them to capture falling leaf litter and other debris, which the plants use for nutrition after the litter has decayed. Litter is trapped via rosettes of leaves, specially modified leaves and/or upward-growing roots (so-called ‘root baskets’). Litter-trappers, both epiphytic and terrestrial, are found throughout the tropics, with only a few extra-tropical species, and they have evolved in many plant families. The trapped litter mass is a source of nutrients for litter-trapping plants, as well as food and housing for commensal organisms. Despite their unique mode of life, litter-trapping plants are not well documented, and many questions remain about their distribution, physiology and evolution.–© 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, ●●, ●●–●●.
... The reasons for this are unclear, but the litter-gathering habit may represent an adaptation to nutrient-poor soils. Nutrients might also be absorbed by the stem epidermis, or by underground roots as debris is washed away to the base of the plant (Hawthorne 2013). Cheek et al. (2008) described Psychotria kupensis (Rubiaceae), another litter-gathering shrub from Central Africa. ...
Background and aims – The taxonomic status of Duvernoia gigantophylla Lindau from southern Cameroon is considered in relation to the wider Justicia extensa-laxa complex of tropical Africa. Its unusual litter-gathering habit (currently unique in Acanthaceae) is also discussed.Methods – This study was based on normal practices of herbarium taxonomy and morphological analysis. All relevant protocols were followed in the production of the conservation assessment and selection of the lectotype. Key results – A new combination Justicia gigantophylla (Lindau) H.J.Sm. & C.Moran is proposed for this narrowly endemic and endangered species, which is re-instated, with a new description and conservation assessment. A basic key to the wider J. extensa-laxa complex is presented. Justicia gigantophylla is assessed as Endangered (EN B1ab(iii)+2ab(iii)) according to the 2012 criteria of IUCN and a new lectotype is also designated.
... The area in south-east Liberia, where the new species is found is a biodiversity hotspot known to be home to several other local endemic species, most of them discovered only recently, including Napoleonaea sapoensis Jongkind (Prance & Jongkind 2015), Pauridiantha liberiensis Ntore (Ntore 2008), Pavetta sapoensis Hawthorne (Hawthorne 2013), Psychotria tetragonopus O. Lachenaud & Jongkind (Lachenaud & Jongkind 2013) and Soyauxia kwewonii Breteler & Jongkind (Breteler, Bakker & Jongkind 2015). At the moment, an important part of the forest in this area being replaced by oil palm plantations. ...
Background: Fieldwork in Liberia in recent years has improved our knowledge of the local endemic species.
Objectives: To describe a new species in Bertiera to accommodate material from the south-east of Liberia that cannot be included in any known species.
Methods: Existing herbarium collections were studied, the new species was studied in the field and the relevant published literature was consulted.
Results: The new species Bertiera sinoensis is described and illustrated here based on six specimens.
Conclusions: The new species adds one more species to the botanical hotspot in south-east Liberia. It is assigned a preliminary conservation status of ‘Endangered’ (IUCN).
Background: The study documented the medicinal plants used to treat diseases and assessed the level of integration of traditional medicine practice (TMP) into the health care delivery system in the study area. Methods: A structured questionnaire was purposively used to select informants from Ghana Federation of Traditional Medicine Practitioners Association. The ethnographic method using a semi-structured questionnaire, interviews and group discussions was employed to collect data for assessing level of integration. The Relative Frequency of Citation (RFC) and Used Value (UV) of the species were determined. Results: A total of 132 medicinal plant species was recorded. The most dominant family was the Fabaceae (19 species), growth form was the tree (76 % of species), the commonly used plant part was the bark (81 species), a disease commonly treated was malaria (34 species), and most common method of drug preparation was decoction (46.1 %). The medicinal plants with the highest RFC (0.90) and UV (1.72) values were Morinda lucida Benth. and Nauclea latifolia Sm. respectively. The low level of integration of TMP into the care health system was mainly due to poor collaboration between TMPs and biomedical staff. Conclusion: Traditional communities rely on medicinal plants for primary healthcare but poor conservation practices put the knowledge and practice of traditional healing at a risk. The integration of TMP into the health care system needs Ghana government`s attention in the study area. Key words: Medicinal plants, Ankasa Forest Reserve, Traditional medicine practice
Background-This contribution is part of an ongoing study on the taxonomy and the phylogenetic relationships of the Malagasy representatives of the tribe Pavetteae (Rubiaceae). Material and methods-Taxonomic methods follow normal practice of herbarium taxonomy. A molecular study using the plastid markers rps16, trnT-F, petD, and accD-psa1, the nuclear ribosomal marker ITS and the nuclear MADS-box gene marker PI was executed. Key results-Five new species are described from littoral, lowland, or mid-elevation humid forests in eastern Madagascar. They are characterized by compact inflorescences with small, sessile flowers, a densely pubescent style, large placentas with 2-3 immersed ovules, seeds with a small, superficial hilum not surrounded by a thickened annulus, and pollen grains with supratectal elements. The phylogenetic tree, which included three of the five new species, showed an unresolved backbone but high support for distal nodes grouping species. The new species form a distinct monophyletic clade among the other Malagasy Pavetteae genera and are recognised at genus level under the name Tarennella. Provisional IUCN Red List assessments show that Tarennella homolleana is Vulnerable, T. cordatifolia and T. sanguinea are Endangered, T. puberula is Critically Endangered, and T. coronata is Critically Endangered (Possibly Extinct).
Background – Botanical exploration of the Sapo National Park in Liberia resulted in the discovery of a new species, which, after DNA investigation, was identified as belonging to Soyauxia of the small family Peridiscaceae.
Methods – Normal practices of herbarium taxonomy and DNA sequence analysis have been applied. All the relevant herbarium material has been studied, mainly at BR, K, P, and WAG. The presented phylogenetic relationships of the new Soyauxia species is based on rbcL gene sequence comparison, inferred by a RAxML analysis including 100 replicates fast bootstrapping. The distribution maps have been produced using Map Maker Pro. Relevant collection data are stored in the NHN (Nationaal Herbarium Nederland) database.
Key results – The new species Soyauxia kwewonii and an imperfectly known species are treated in the framework of a synopsis with the six other species of the genus. rbcL sequence comparison followed by RAxML analyses yielded a well-supported match of S. kwewonii with the Soyauxia clade. Its conservation status according to the IUCN red list criteria is assessed as Endangered. Its distribution as well as the distribution areas of the genus and of the remaining species are mapped. Soyauxia ledermannii is neotypified and the most common species in Gabon, S. glabrescens, is also illustrated.
Analyses of distribution, diversity, endemism, and taxonomic effort for Rubiaceae are reported, based on queries from a World Rubiaceae Checklist database. Rubiaceae are widespread and occur in all major regions of the world except the Antarctic Continent, but are predominantly a group in the tropics with greatest diversity in low- to mid-altitude humid forests. A count of Rubiaceae species and genera is given (13,143 spp./611 genera), which confirms that this is the fourth largest angiosperm family. Psychotria L. is the largest genus in the Rubiaceae (1834 spp.) and the third largest angiosperm genus. Most genera (72%) have fewer than 10 species and 211 are monotypic. Calculation of relative species diversity and percentage endemism enables areas of high diversity and endemism to be enumerated, and identifies areas where further field collecting and taxonomic research are required. Endemism is generally high in Rubiaceae, which supports data from recent studies showing that many species have restricted distributions. Given the assumed ecologic sensitivity of Rubiaceae, in combination with a range of other factors including restricted distribution, we suggest that species in this family are particularly vulnerable to extinction. The rate at which new species are being described is inadequate; more resources are required before the diversity of Rubiaceae is satisfactorily enumerated.
Over 400 species of three genera of Rubiaceae and one genus of Myrsinaceae reportedly have bacterial leaf nodules. Light and/or
electron microscope studies of a few species have shown that bacteria exist in spaces within buds filled with mucilage secreted
by glands. These bacteria enter substomatal chambers (Rubiaceae) or marginal hydathodes (Myrsinaceae) and establish short-lived
colonies, in intercellular spaces, that die out almost before full leaf expansion. Bacteria occur in seeds between endosperm
and embryo, but only two studies have followed bacteria into flowers and ovules. Previous work on the physical relations of
bacteria and host plants is discussed critically. Reviewing work done on isolation and identification of presumed endophytes
leads to the conclusion that there is no agreement whether one or several bacterial taxa are the endophyte, and no unambiguous
identifications, although four genera are suggested as possibilities. Nitrogen fixation was considered as the bacterial contribution
until quite recently, but a review of such studies reveals that fixation has been detected almost exclusively in isolated
presumed endophytes, whereas almost all studies involving the bacterium in intact leaves have failed to detect nitrogen fixation.
Studies of particular substances (besides combined nitrogen) contributed by the endophyte have been inconclusive, although
the most recent works suggest that cytokinins are involved. Host plants lacking the endophyte have been reportedly produced
many times, either spontaneously or by seed treatment. Such “cripples”, used for several aspects of symbiosis study, frequently
revert to a nodulated condition, and a more reliable method of producing them is needed. Tissue culture may offer the best
potential, but this approach has not yet produced whole bacteria-free plants. A proposed scheme for the evolution of the symbiosis
suggests that a variety of bacteria entered buds first, and only in rare instances were compatible with the host bud mucilage.
In a few of these cases, specific bacteria, compatible with the microenvironment, contributed a useful substance to the host,
and bud mucilage and those bacteria co-evolved until large numbers of bacteria thrived in the buds. Nodules may have resulted
from accidental entry of bacteria into leaves, with the possibility that some host plant nodules are merely pathogenic responses,
whereas in others the bacteria are beneficial and further selection has resulted in numerous, regularly produced nodules.
This review deals with taxonomy of host plants and endophytes, morphology of the symbiosis, its physiology, and speculation
on the evolution of the symbiosis.
Über 400 Arten der drei Gattungen von Rubiaceae und eine Gattung von Myrsinaceae haben, wie berichtet ist, bakterielle Blatt-Knötchen.
Licht und/ oder elektron-mikroskopische Studien von einigen Arten haben gezeigt, dass Bakterien existieren in Räumen innerhalb
von Knospen, die von Pflanzenschleim ausegefüllt sind, von Drüsen erzeugt. Diese Bakterien dringen in unteren-Spaltöffnungs-Räume
ein (Rubiaceae) oder Rand-Wasser-Poren (Myrsinaceae) und bilden kurzlebende Kolonien, in Räumen zwischen den Zellen, welche
aussterben, fast bevor der völligen Blattentfaltung. Bakterien finden sich in Samen zwischen dem Endosperm und dem Embryo,
aber nur zwei Untersuchungen konnten den Bakterien nachfolgen in die Blüten und die Eier. Frühere Arbeit über die physikalischen
Beziehungen zwischen Bakterien und Wirtspflanzen ist kritisch besprochen. Nachprüfende Arbeit ist unternommen an der Isolierung
und Identifizierung an vermutlichen Endophyten und führt zu dem Ergebnis, dass da keine Einigung besteht, ob eine oder mehrere
bakterielle Gruppen die Endophyten sind, und keine unzweideutige Identifikationen, trotzdem 4 Gattungen als Möglichkeiten
vorgeschlagen sind. Bis ziemlich kürzlich wurde Stickstoff-Fixierung als Bakteriellen-Beitrag angesehen, aber ein Überblick
über solche Untersuchungen ergiebt, dass Fixierung wurde festgestellt nahezu ausschliesslich in isolierten, vermutlichen Endophyten,
wogegen fast alle Untersuchungen, die sich auf Bakterien in unverletzten Blattern bezogen, versagt haben, Stickstoff-Fixierung
festzustellen. Untersuchugen von besonderen Substanzen (ausser kombiniertem Stickstoff), von den Endophyten beigetragen, sind
nicht entscheidend gewesen, wenn auch die aller-jüngsten Arbeiten andeuten, dass cytokinins verwickelt sind. Wirtspflanzen,
die das Endophyte entbehren, sind, wie berichtet ist, fielfach erzeugt worden, entweder spontan oder durch Behandlung der
Samen. Solche “Krüppel, ” welche in verschiedener Hinsicht für das Studium von Symbiose verwendet wurden, schlagen häufig
zu einer Knötchen-Beschaffenheit zurück, und eine besser zuverlässige Methode, sie zu erzeugen, ist notwendig. GewebeKulturen
mögen eine bessere Möglichkeit bitten, aber diese Annäherung hat bislang noch nicht gänzliche bakteriumfreie Pflanzen erzeugt.
Eine vorgeschlagene Methode für die Evolution der Symbiose nimmt an, dass eine Art von Bakterien zuerst in die Knospen eindringen,
und nur in seltenen Fällen verträglich waren mit dem Pflanzenschleim der Wirts-Knospen. In einigen wenigen dieser Fälle haben
besondere Bakterien, verträglich mit der Mikro-Umbebung, dem Wirt eine nützliche Substanz beigetragen, und Knospenschleim,
und die Bakterien sind zusammen aufgetreten, bis eine grosse Zahl von Bakterien in den Knospen gediehen. Knötchen können sich
ergeben haben vom zufälligen Eintritt von Bakterien in Blätter, mit der Möglichkeit, dass einige Wirtspflanzen-Knötchen lediglich
pathologische Rückwirkungen sind, wogegen in anderen die Bakterien nützlich sind, und weitere Selektion resultierte in zahlreichen,
normalerweise erzeugten Knötchen.
Dieser Überblick handelt sich mit der Taxonomie von Wirtspflanzen und Endophyten, Morphologie der Symbiose, ihrer Physiologie,
und Spekulation über die Evolution der Symbiose.
Plus de quatre cents espèces de trois genres de Rubiacées et un genre de Myrsinacées possèdent des nodules bactériens dans
les feuilles. Les études des microscopes lumineux et/ou des microscopes électroniques ont révélé que les bactéria se trouvent
dans les espaces à l’intérieur des bourgeons qui sont remplis mucilage sécreté par les glandes. Ces bactéria entrent dans
les chambres substomatales (Rubiacées) ou dans les hydathodes périphériques (Myrsinacées) et elles establissent dans les espaces
intercellulaire des colonies de courte durée qui meurent presque avant l’expansion complète de la feuille. Les bactéria se
trouvent dans les graines entre l’endosperm et l’embryon mais seulement deux études ont trouvé les bactéria dans les fleurs
et les ovules. Les travaux précédents au sujet des rapports physiques des bactéria avec des hôtes sont discutés d’une manière
critique. L’examination du travail fait au sujet de l’isolation et de l’identification des endophytes presumés mène à la conclusion
qu’il n’y a pas d’accord soit une taxum bactérienne soit plusieurs taxa bactériennes sont l’endophyte et il n’y a pas d’identification
certaine, bien que quatre genres soient suggérés comme possibilities. La fixation du nitrogène était considerée comme la contribution
bactérienne jusqu’a ces derniers temps, mais une revue de telles études révèle que la fixation était decouverte presque exclusivement
dans des endophytes presumés isoles, tandis qu’au contraire presque toutes les études ou les bactéria sont dans les feuilles
intactes n’ont pas reussi a decouvrir la fixation du nitogène. Des études des matières particulières (en plus de nitrogène
combinè) qui sont contribuées par l’endophyte avaient été peu concluant, bien que les travaux les plus récents suggèrent que
les cytokinins soient engagés. On a dit que les hôtes qui manquent l’endophyte étaient produits plusieurs fois, soit spontanément
soit par le traitement des graines. Ces “estropies”, utilizés pour l’étude de quelques aspects de symbiose, frequemment reviennent
à une condition nodulaire et on a besoin d’une meilleure méthode pour les produire. La culture de tissus peut offrir le meilleure
possibilité mais cet abord n’a pas encore produit de plantes entières qui sont sans bactéria. Un plan proposé pour l’évolution
de la symbiose suggere qu’une variété de bactéria est entrée premièrement dans les bourgeons et seulement dans des cas rares
les bacteria étaient compatible avec le mucilage des bourgeons de l’hôte. Dans quelquesuns de ces cas des bactéria spécifiques
qui étaient compatible avec le micromilieu ont contribués une substance utile a l’hôte. Aussi le mucilage des bourgeons et
ces bactéria ont dévelopé ensemble jusqu’a ce qu’un grand nombre de bactéria se developpaient bien dans les bourgeons. Les
nodules pouvaient résulter de l’entrée accidentel de bactéria dans les feuilles avec la possibilité que les nodules de quelques
hôtes sont tout simplement des réponses pathogéniques, tandis qu’au contraire dans quelques autres hôtes les bactéria sont
avantageux pour les hôtes et le résultat de sélection additionnelle est de nombreux nodules produits regulièrements. Cette
revue traite de la taxonomie des hôtes et des endophytes; la morphologie de la symbiose; la physiologie de la symbiose; et
la speculation sur l’évolution de la symbiose.
In this review, we discuss the ecological and evolutionary consequences of plant- herbivore interactions in tropical forests. We note first that herbivory rates are higher in tropical forests than in temperate ones and that, in contrast to leaves in temperate forests, most of the damage to tropical leaves occurs when they are young and expanding. Leaves in dry tropical forests also suffer higher rates of damage than in wet forests, and damage is greater in the understory than in the canopy. Insect herbivores, which typically have a narrow host range in the tropics, cause most of the damage to leaves and have selected for a wide variety of chemical, developmental, and phenological defenses in plants. Pathogens are less studied but cause considerable damage and, along with insect herbivores, may contribute to the maintenance of tree diversity. Folivorous mammals do less damage than insects or pathogens but have evolved to cope with the high levels of plant defenses. Leaves in tropical forests are defended by having low nutritional quality, greater toughness, and a wide variety of secondary metabolites, many of which are more common in tropical than temperate forests. Tannins, tough- ness, and low nutritional quality lengthen insect developmental times, making them more vulnerable to predators and parasitoids. The widespread occurrence of these defenses suggests that natural enemies are key participants in plant de- fenses and may have influenced the evolution of these traits. To escape damage, leaves may expand rapidly, be flushed synchronously, or be produced during the dry season when herbivores are rare. One strategy virtually limited to tropical forests is for plants to flush leaves but delay "greening" them until the leaves are mature. Many of these defensive traits are correlated within species, due to physiological constraints and tradeoffs. In general, shade-tolerant species invest more in defenses than do gap-requiring ones, and species with long-lived leaves are better defended than those with short-lived leaves.
■ Abstract Protective ant-plant interactions, important in both temperate and trop- ical communities, are increasingly used to study a wide range of phenomena of general interest. As antiherbivore defenses "worn on the outside," they pose fewer barriers to experimentation than do direct (e.g., chemical) plant defenses. This makes them tractable models to study resource allocation to defense and mechanisms regulating it. As multi-trophic level interactions varying in species specificity and impact on fitness of participants, ant-plant-herbivore associations figure prominently in studies of food-web structure and functioning. As horizontally transmitted mutualisms that are vulnerable to parasites and "cheaters," ant-plant symbioses are studied to probe the evolutionary dynamics of interspecies interactions. These symbioses, products of coevolution between plants and insect societies, offer rich material for studying ant social evolution in novel contexts, in settings where colony limits, resource supply, and nest-site availability are all more easily quantifiable than in the ground-nesting ants hitherto used as models.
Parsimony analyses of morphology, restriction sites of the cpDNA, sequences from the nuclear, ribosomal internal transcribed spacer (ITS), and the chloroplast gene rbcL were performed to asses tribal and generic relationships in the subfamily Ixoroideae (Rubiaceae). The tribes Vanguerieae and Alberteae (Antirheoideae) are clearly part of Ixoroideae, as are some Cinchonoideae taxa. Pavetteae should exclude Ixora and allies, which should be recognized as the tribe Ixoreae. Heinsenia, representing Aulacocalyceae, is part of Gardenieae, as is Duperrea, a genus earlier placed in Pavetteae. Posoqueria and Bertiera and the taxa in the subtribe Diplosporinae should be excluded from Gardenieae. Bertiera and three Diplosporinae taxa are part of Coffeeae, while Cremaspora (Diplosporinae) is best housed in a tribe of its own, Cremasporeae. The mangrove genus Scyphiphora, recently placed in Diplosporinae, is closer to Ixoreae and tentatively included there. The combined analysis resulted in higher resolution compared to the separate analyses, exemplifying that combined analyses can remedy the incapability of one data set to resolve portions of a phylogeny. Twenty-four new rbcL sequences representing all five Ixoroideae tribes (sensu Robbrecht) are presented.
Fourteen new species of Pavetta (Rubiaceae) are described: five from the Flora Zambesiaca region (P. chapmanii, P. garueensis, P. mulleri, P. vanwykiana, P. whiteana), eight from the flora of Tropical East Africa (FTEA) region (P. bidgoodiae, P. delicatifolia, P. diversipunctata, P. indigotica, P. lulandoensis, P. matumbiensis, P. pocsii, P. roseostellata) and one (P. micropunctata) occurring in both regions. Three of them were previously included in Bridson & Verdcourt (1988) as Pavetta sp. C, P. sp. D & P. sp. E. The identity of one more informal taxon, Pavetta sp. F is established as P. pierlotii Bridson. One new subspecies, P. abyssinica Fresen. subsp. viridiflora, is described and P. appendiculata De Wild. is reduced to a variety of P. gardeniifolia A. Rich. The infrageneric position of P. roseostellata is discussed in relation to P. sp. A (Bridson & Verdcourt 1988). Two species, P. incana Klotzsch and P. klotzschiana K. Schum., are neotypified. The placement in synonymy by Bremekamp of P. arenicola K. Schum. and P. stipulopallium K. Schum. under P. schumanniana F. Hoffm. ex K. Schum. is challenged. Notes are included on P. kyimbilensis Bremek. var. kyimbilensis and a poorly known affiliated taxon. Supplementary data are given for P. lindina Bremek. and P. tendagurensis Bremek.
A survey of the genera of the Pavetteae is given. Coptosperma, Santalina, Pachystylus, Stylocoryna, Bonatia, Canthiopsis and Tennantia are related to Tarenna. The following genera are considered allied to Ixora: Myonima, Hitoa, Doricera, Thouarsiora and Versteegia. Coleactina is accepted as affiliated to Leptactina. Duperrea remains of unknown affinity within the tribe. Some poorly known Madagascan genera suspected of belonging to the Pavetteae, viz. Paracephaelis, Schizenterospermum, Homollea and Homoliella, are briefly discussed. Finally the following genera may definitely be excluded from the tribe: Gardeniopsis, Brachytome, Strumpfia, Phyllomelia and Cosmocalyx. The characters of the Pavetteae are reviewed. With the exception of the pantropical genus Ixora, the tribe is paleotropical.
Pavetta subg. Baconia (Rubiaceae tribe Pavetteae) is a group of forest shrubs in tropical and subtropical Africa. It includes species of Pavetta with bearded corolla throats, corolla tubes usually shorter than corolla lobes, terete or subterete style tips, and fruits usually of colors other than black. Cameroon is a major center of diversity for subgenus Baconia, and the Cameroon species are revised here. Twenty-nine species are recognized, including eleven newly described; five previously recognized species are placed in synonymy. Seven series used earlier to subdivide subgenus Baconia have been abandoned owing to inconstancy of character states used to delimit most of them. Sixteen Cameroon species are presently unreported from elsewhere. Infraspecific taxa are recognized in seven of the twenty-nine species. Aspects of leaf morphology are useful taxonomically. An overview is provided of these, other aspects of morphology, habitat preferences, and reproductive strategies. Habitat preferences, distributions, and distinguishing features follow descriptions of each species.
This paper contains descriptions of 13 new taxa (including 8 new species) and 22 hew combinations; synonymies and distributions are provided where necessary.
Background - Five new species of Psychotria (Rubiaceae) from West Africa are described and illustrated, in the framework of a regional revision of the genus. Methods - Normal practices of herbarium taxonomy have been applied. Key results - Three of the new species, Psychotria baldwinii, P. tetragonopus and P. voorhoevei, are endemic to Liberia, while the other two, P. blydeniae and P. rubriceps, also occur in adjacent southwestern Cote d'Ivoire. The Ivorian endemic Psychotria copeensis, previously included in the synonymy of P. subobliqua, is separated as a distinct species. Psychotria blydeniae and P. tetragonopus are litterbin plants; we discuss this remarkable adaptation and its occurrence in various Angiosperm families in the African rainforests.
Leaf nodules represent the most visible aspect of a group of symbiotic relationships, which are arguably the most complex and certainly has the most intimate associations between bacteria and higher plants. This intimacy lies in the fact that the bacteria are constant and obligate companions of the host throughout the plant's entire life cycle and hence these relationships have come to be described as “cyclic symbioses.” Colonies of bacteria are maintained in a protein/carbohydrate based mucilage within every vegetative shoot tip of the host plant, acting as a source of inoculum for the infection of each new developing leaf. At the onset of flowering, the bacteria are transferred into the floral shoot tip and, during floral organogenesis, are placed within the embryo sac of the developing ovule. As the ovule develops into a seed, the bacteria are somehow positioned on the epicotyl of the embryo where, upon germination of the seed, they become enclosed in the shoot tip of the seedling where they infect the first leaves of the next host plant generation. In these relationships, the leaf nodules per se, although highly visible, are but a relatively small part of the story. A more complicated sequence of plant-microbe interactions occurs at a microscopic level within the host plant throughout its entire life cycle. This chapter describes the present state of understanding of the interactions that occur in these complex cyclic symbioses and describes, at the ultrastructural level the interesting, if somewhat bizarre, ecosystem to which these leaf nodule microsymbionts have become adapted.
INVESTIGATIONS of the symbioses in root-nodules of legumes and non-legumes have established that nitrogen fixation occurs in the nodular tissue1. Although some reports have appeared describing the leaf-nodule symbiosis in Psychotria
2–4 no isolate of the endophyte is at present available, and it has not been unequivocally established that nitrogen fixation is involved. We now report that the isolated endophyte fixes atmospheric nitrogen in pure culture and, apparently, in the plant as well. It is known that plants either naturally or experimentally freed of the endophyte are dwarfs2,3. Nitrogen fixation does not fully account for these observed effects.
A distinctive new species of dwarf monocaulous Coffea (Rubiaceae) from Cameroon is described and illustrated. Coffea mapiana is the second dwarf monocaulous known from Cameroon. Its diagnostic characters are elucidated and its taxonomic affinities are discussed; a conservation assessment is provided. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 151, 425–430.
Buds removed from herbarium specimens were processed for light microscopic examination of colleter form and anatomy. Most Pavetta species have dendroid colleters and bacterial leaf nodules, a correlation also found in an earlier study of Psychotria. Colleters of Neorosea, another genus with leaf-nodulated species, are more like the standard rubiaceous type that predominates in the family except that they have irregular, bulging epidermal cells. Tricalysia, a nodule-free genus closely related to Neorosea, shows a range of colleter form from standard to dendroid, and some species have the Neorosea type of colleter. Such morphological correlation between the bacterial leaf nodule symbiosis in Pavetta and Psychotria and dendroid colleters may indicate a chemical change in colleter secretion. Apart from their involvement with the bacterial symbiosis, rubiaceous colleters have now been shown to vary sufficiently in certain taxa to be considered as additional useful taxonomic characters.
Jongkind and students of Université de Cocody of Abidjan 4439 (WAG). LIBERIA. Bomi Hills nr Yoma on left bank of Mahe R., 12 km NE of Bomi hills Leeuwenberg 4837 (holotype WAG, 2 sheets); Bomi Hills nr Gbama
- Tabou
- Fc
- Dodo
- Kouadjokro 5°n
- C C H 7°18 'w
Tabou, FC de la Ht Dodo, nr Kouadjokro, alt 150 m, 5°N, 7°18'W, C. C. H. Jongkind and students of Université de Cocody of Abidjan 4439 (WAG). LIBERIA. Bomi Hills nr Yoma on left bank of Mahe R., 12 km NE of Bomi hills, 5 Aug. 1962, Leeuwenberg 4837 (holotype WAG, 2 sheets); Bomi Hills nr Gbama, 17 Oct. 1965, P. P. C. van de Meer 223 (WAG); Bomi hills, Gola National Forest, 22 July 1965, P. P. C. van de Meer 14 (WAG);
Further notes on the tribe Pavetteae (Rubiaceae) Rubiaceae, pt 2
- Robbrecht
- E
- B Verdcourt
____ & Robbrecht, E. (1985). Further notes on the tribe Pavetteae (Rubiaceae). Bull. Jard. Bot. Nat. Belg. 55 : 83 – 115 ____ & Verdcourt, B. (1988). Rubiaceae, pt 2. Flora of Tropical East Africa: pp. 415 – 747.
P. quasidigita 2'. Leaves without " fingerprint " venation; finer venation more or less isotropic with similar numbers of veins References
- ................................................................ Sw Ivory Coast
Leaves with highly anisotropic finer venation (VDA ≥3) creating a distinctive fingerprint-like pattern; SW Ivory Coast................................................................... P. quasidigita 2'. Leaves without " fingerprint " venation; finer venation more or less isotropic with similar numbers of veins References Andreasen, K. & Bremer, B. (2000). Combined Phylogenetic Analysis in the Rubiaceae-Ixoroideae:
20'N, 8°47.70'W alt. 90 – 100 m
- Sino County
- Sapo Np Close
- R Sinoe
- °
Sino county, Sapo NP close to Sinoe R., 5°20.20'N, 8°47.70'W alt. 90 – 100 m, 11 March 2009, C. C. H. Jongkind, D. Bilivogui & D. Dorbor 8944 (WAG);
5°13'15"N, 2°38'51"W, 22 Feb
- Nr
- Gate
- R Ankasa
nr southern gate and Ankasa R., 5°13'15"N, 2°38'51"W, 22 Feb. 1990, Hawthorne, Abu Juam, Orgle, Gyakari, Ekpe AR186 (holotype FHO; isotype K, GC);
Western Region: Locality 2. Draw R. forest reserve, riverside within protected area adjacent to Ankasa forest, c. 2 km from pillar 10 on Brepro footpath: 14
- Hawthorne
- Wh203a119 Gyakari
- Fho
- Gc
23 April 2003, Hawthorne & Gyakari WH203A119 (FHO, GC). Western Region: Locality 2. Draw R. forest reserve, riverside within protected area adjacent to Ankasa forest, c. 2 km from pillar 10 on Brepro footpath: 14 March 2002, Hawthorne, Abu Juam, Ekpe & Gyakari DRAWG 89 (GC, FHO). IVORY COAST. Aboisso. Danvi, 1 – 4 April 1907, Chevalier 17849 (P).
Ants and their diverse relations to the plant world
- J Bequaert
World Checklist of Rubiaceae. The Board of Trustees of the Royal Botanic Gardens
- R Govaerts
- M Ruhsam
- L Andersson
- E Robbrecht
- D M Bridson
- A P Davis
- I Schanzer
- B Sonké
IUCN Red list categories and criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland and Cambridge
- Iucn