Biology subjects

Cheek, M.

Publications and source records attributed to Cheek, M..

54 records · Page 3Linked to original sources

bioRxiv2021

The endemic plant species of Bali Ngemba Forest Reserve, Bamenda Highlands Cameroon, with a new Endangered cloud-forest tree species Vepris onanae (Rutaceae).

We revise and update the records of strict and near-endemic species of the Bali Ngemba Forest Reserve, the largest known surviving patch (c. 8 km2 in area) of submontane or cloud forest in the Bamenda Highlands, Cameroon which have lost >96 % of their original forest due to human activities. Nine strict endemics, and 11 near endemics are now documented, a drop from the number recorded after the first survey in 2004, since when five of the provisionally named species have been formally published. We test the hypothesis that a further one of the provisionally named putative Bali Ngemba new species, Vepris sp. A, an 8 - 20 m tall tree from cloud forest in the 1310 - 1600 m altitudinal band, is indeed new to science. We compare it morphologically with other multicarpellate, apocarpous, trifoliolate Cameroon tree species formerly placed in the genus Oricia Pierre until they were subsumed into Vepris by Mziray (1992). These are Vepris trifoliolata (Engl.) Mziray and V. gabonensis (Pierre) Mziray. We conclude that Vepris sp. A is a new undescribed species here named as Vepris onanae. The new species is illustrated, mapped and its conservation status assessed as Endangered using the 2012 IUCN standard due to the threats of habitat clearance from agricultural pressures at its three locations all of which remain formally unprotected. Vepris onanae appears unique among the Guineo-Congolian African oricioid species of Vepris in occurring in cloud forest, the other species, apart from V. renierii of the Albertine Rift, occurring in lowland forest. It also differs in the very broad, (7.8 -) 11.3 - 18 cm wide leaflets of the flowering stems which have a 6-18(-30) mm long, narrowly triangular acumen (vs leaflets <12 cm wide, acumen absent or short) and in having both subsessile and pedicellate (pedicels 0.25 - 0.3 mm long and 1(- 2) mm long) male flowers (vs male flower pedicels all sessile, or all c. 3 mm long). We report for the first time on stage-dependent leaf heteromorphy in Vepris and characterise a level of sexual dimorphism more advanced than usual in the genus. We highlight the importance of protecting Bali Ngemba and other forest patches in the Bamenda Highlands if species such as Vepris onanae are not soon to become extinct.

plant biology↗

bioRxiv2021

Chemistry, Taxonomy and Ecology of the potentially chimpanzee-dispersed Vepris teva sp.nov. (Rutaceae) of coastal thicket in the Congo Republic

Continuing a survey of the chemistry of species of the largely continental African genus Vepris, we investigate a species previously referred to as Vepris sp. 1 of Congo. From the leaves of Vepris sp. 1 we report six compounds. The compounds were three furoquinoline alkaloids, kokusaginine (1), maculine (2), and flindersiamine (3), two acridone alkaloids, arborinine (4)and 1-hydroxy-3-methoxy-10-methylacridone (5), and the triterpenoid, {beta}-amyrin (6). Compounds 1-4 are commonly isolated from other Vepris species, compound 5 has been reported before once, from Malagasy Vepris pilosa, while this is the first report of {beta}-amyrin from Vepris. This combination of compounds has never before been reported from any species of Vepris. We test the hypothesis that Vepris sp.1 is new to science and formally describe it as Vepris teva, unique in the genus in that the trifoliolate leaves are subsessile, with the median petiolule far exceeding the petiole in length. Similar fleshy-leathery 4-locular syncarpous fruits are otherwise only known in the genus in Vepris glaberrima (formerly the monotypic genus Oriciopsis Engl.), a potential sister species, but requiring further investigation to confirm this phylogenetic position. We briefly characterise the unusual and poorly documented Atlantic coast equatorial ecosystem, where Vepris teva is restricted to evergreen thicket on white sand, unusual in a genus usually confine to evergreen forest. This endemic-rich ecosystem with a unique amphibian as well as plants, extends along the coastline from the mouth of the Congo River to southern Rio Muni, a distance of about 1000 km, traversing five countries. We map and illustrate Vepris teva and assess its extinction risk as Endangered (EN B1ab(iii)+B2ab(iii)) using the IUCN standard. Only three locations are known, and threats include port and oil refinery construction and associated activities, with only one protected location, the Jane Goodall Institutes Tchimpounga Reserve. Initial evidence indicates that the seeds of Vepris teva are dispersed by chimpanzees, previously unreported in the genus

plant biology↗

bioRxiv2021

Taxonomic Monograph of Saxicolella (Podostemaceae), African waterfall plants highly threatened by Hydro-Electric projects, with five new species.

The genus Saxicolella Engl. (Podostemaceae) are African rheophytes, restricted to rapids and waterfalls as are all members of the family. Previously, Saxicolella sensu lato was shown to be polyphyletic with two separate clades in the molecular phylogenetic study of Koi et al. (2012). The name Pohliella Engl. was recently resurrected for one clade that is sister to the American genera Ceratolacis (Tul.)Wedd., Podostemum Michx. and all Old World Podostemoideae (podostemoids) (Cheek 2020). Pohliella has distichous phyllotaxy, bilocular ovaries, filiform roots with paired holdfasts, and rootcaps. The second clade, Saxicolella sensu stricto, including the type of the generic name, has spiral phyllotaxy, unilocular ovaries, ribbon-like or crustose roots that lack both holdfasts and rootcaps. Saxicolella sensu stricto, sampled from the type species, S. nana Engl. of Cameroon, is embedded within and near the base of the major clade of African podostemoids and is sister to all other African genera apart from Inversodicraea R.E.Fr. and Monandriella Engl. Recently reduced to three species in Cameroon and S.E. Nigeria by the resurrection of Pohliella (3 - 4 species in Ghana and Nigeria-Cameroon), Saxicolella sensu stricto is expanded to eight species in this monograph by description of five new taxa. Saxicolella futa Cheek and S. deniseae Cheek are newly described from Guinea, S. ijim Cheek from Cameroon, the informally named S. sp. A from Gabon, and S. angola Cheek from Angola. The known geographic range of the genus is thus expanded c. 2,500 km westwards to Guinea from eastern Nigeria and c.1,500 km southeastwards from near Yaounde to Cuanza do Sul, Angola. The greatest concentration of species occurs in the Cross-Sanaga interval of western Cameroon and eastern Nigeria, with three species. Cameroon (3 species) followed by Nigeria and Guinea (2 species each) are the countries with highest species diversity. The genus can be expected to be found in Sierra Leone, Liberia, Ivory Coast and Congo Republic. A classification is proposed grouping the species into three subgenera (Saxicolella, Butumia (G.Taylor) Cheek comb. et. stat. nov. and Kinkonia Cheek subgen. nov.) based on root morphology and shoot position and morphology. The discovery, morphology, circumscription, distribution, and ecology of Saxicolella is reviewed, an identification key to the species is presented, together with descriptions, synonymy, links to illustrations, and extinction risk assessments for each of the eight species now recognised. All of the species are provisionally assessed as either Endangered or Critically Endangered using the IUCN 2012 standard, making this genus among the most threatened of its size globally. The major threats, above all, are hydro-electric projects. Saxicolella deniseae may already be globally extinct, and two of the four known locations of S. angola appear lost, S. sp. A of Gabon is threatened at at least one of its three locations, while Saxicolella futa is threatened at all three locations, all due to incipient or active hydro-electric projects. Contamination of watercourses by increased turbidity from silt-load due anthropic changes and by eutrophication from pollution are also threats for the majority of the species.

plant biology↗

bioRxiv2021

The endemic plant species of Mt Kupe, Cameroon with a new Critically Endangered cloud-forest tree species, Vepris zapfackii (Rutaceae).

We revise and update the records of strict and near-endemic species of Mt Kupe, Cameroon respectively from 31 strict endemics in 2004, to 25 today, and with near-endemic species 30, unchanged in number but with turnover. The changes result from new collections, discoveries and taxonomic changes in the last 16 years. While 15 of the provisionally named putative endemic species have now been formally published, a further 18 have not. The majority of the 30 near-endemic species (18) are shared with the adjacent Bakossi Mts, far exceeding the numbers shared with the more distant Mt Etinde-Mt Cameroon, Rumpi Hills and Ebo forest areas (sharing three near-endemic species each with Mt Kupe). We test the hypothesis that a further one of the provisionally named putative Mt Kupe species, Vepris sp. 1 from submontane forest near the summit, is indeed new to science. We compare it morphologically with the two other bicarpellate high altitude Cameroon Highland tree species Vepris montisbambutensis Onana and Vepris bali Cheek, concluding that it is a new undescribed species here named as Vepris zapfackii. The new species is illustrated, mapped and its conservation status assessed as Critically Endangered using the 2012 IUCN standard due to habitat clearance from agricultural pressures at its sole location which is unprotected. Vepris zapfackii and V. bali appear unique in African trifoliolate species of the genus in having opposite leaves. Vepris zapfackii differs in having hairy petiolules and midribs and petiolules with the blade decurrent distally, narrowing towards a winged-canaliculate base (vs glabrous and petiolule long, terete), and sparsely golden hairy pistillodes and a glabrous calyx (vs densely black hairy pistillodes, and sepals hairy).

plant biology↗

bioRxiv2021

Four new threatened species of Rinorea (Violaceae), treelets from the forests of Cameroon

Four species of Rinorea are described as new to science; all four species are endemic to evergreen rain forest in Cameroon. Rinorea villiersii Achound., and Rinorea amietii Achound. are placed in Sect. Crassiflorae Wahlert, while Rinorea dewildei Achound. and Rinorea faurei Achound. fall in Rinorea section Dentatae (Engl.) Wahlert. The first species appears to be endemic to the Sole Forest Reserve northeast of Yabassi in Littoral Region. The second and the third species are found mainly in Littoral and South Regions, Rinorea amietii extending to South West Region and Rinorea dewildei extending to Central Region. The fourth species, Rinorea faurei is an endemic of the Santchou Forest Reserve at the foot of Dschang Plateau in West Region. The affinities of the four species are discussed, they are illustrated and mapped, and their conservation status is assessed. All four species are threatened with extinction according to the 2012 IUCN categories and criteria.

plant biology↗

bioRxiv2021

Lukea gen. nov. (Monodoreae-Annonaceae) with two new species of shrub from the forests of the Udzungwas, Tanzania & Kaya Ribe, Kenya.

A new genus, Lukea Gosline & Cheek (Annonaceae), is erected for two new species to science, Lukea quentinii Cheek & Gosline from Kaya Ribe, S.E. Kenya, and Lukea triciae Cheek & Gosline from the Udzungwa Mts, Tanzania. Lukea is characterised by a flattened circular bowl-shaped receptacle-calyx with a corolla of three petals that give the buds and flowers a unique appearance in African Annonaceae. Both species are extremely rare shrubs of small surviving areas of lowland evergreen forest under threat of habitat degradation and destruction and are provisionally assessed as Critically Endangered and Endangered respectively using the IUCN 2012 standard. Both species are illustrated and mapped. Material of the two species had formerly been considered to be possibly Uvariopsis Engl. & Diels, and the genus Lukea is placed in the Uvariopsis clade of the Monodoreae (consisting of the African genera Uvariodendron (Engl. & Diels) R.E.Fries, Uvariopsis, Mischogyne Exell, Dennettia Bak.f., and Monocyclanthus Keay). The clade is characterised by often conspicuous, finely reticulate quaternary nervation and incomplete or absent connective shields (in Annonaceae the connective shield is usually complete). Morphologically Lukea is distinct for its broad, turbinate, fleshy pedicel, a synapomorphy. It appears closest to the West African monotypic Monocyclanthus, sharing a trait unusual in the Annonaceae: the calyx in both genera forms a shallow bowl (calyx lobes are absent or vestigial), barely enclosing the base of the petals at anthesis, and persisting as a living, leathery disc at least until the fruit is mature. The placement of Lukea within the Uvariopsis clade is discussed.

plant biology↗

bioRxiv2021

Uvariopsis ebo (Annonaceae) a new, Critically Endangered tree species from the Ebo Forest, Cameroon and a key to the Cameroonian species of Uvariopsis

A new species to science of evergreen forest tree, Uvariopsis ebo (Annonaceae) is described, illustrated, mapped, and compared morphologically with the other cauliflorous species of the genus. Restricted so far to a single site in evergreen lowland forest in the Ebo Forest, Yabassi, Littoral Region, Cameroon, this species is Critically Endangered using the IUCN 2012 standard, because the forest habitat of this species remains unprotected, and there exists threats of logging and conversion to plantations. This species adds to the growing list of threatened species resulting from anthropogenic pressure on Cameroon forests. Observations on the unusual corolla structure of the new species are made. A revised key to the 14 Cameroonian species of Uvariopsis is presented. Notes are given on other narrowly endemic and threatened species in the Ebo forest area, a highly threatened centre of diversity in Littoral Region, globally important for conservation.

plant biology↗

bioRxiv2021

Pseudohydrosme bogneri sp. nov. (Araceae), a spectacular Critically Endangered (Possibly Extinct) species from Gabon, long confused with Anchomanes nigritianus.

A Gabonese taxon cultivated for decades in the botanic gardens of Europe as Anchomanes nigritianus is shown to be a new species to science, and on current evidence, is best placed as the fourth species of the Gabonese-centred, poorly known genus Pseudohydrosme. Data on the morphological separation between Anchomanes and Pseudohydrosme are reviewed. Although phylogenomic studies may show in future that the two genera need to be merged, for the moment their separation is reinforced on morphological grounds. Anchomanes lacks the spathe tube, ovoid-globose, 2 - 4 locular pistil and thick, lobed stigma on a symmetric, stout style that we show to characterise the redelimited Pseudohydrosme. (Anchomanes has oblong, polygonal, 1-locular pistils, stigmas asymmetric, sessile, thin and disc-like or on asymmetrical conical styles and are pointed or brush-like). In addition, Pseudohydrosme (where known) has stipitate (versus sessile) fruits and on current evidence lacks the lacticifers recorded from Anchomanes. We test the hypothesis that the taxon is a new species to science, naming it as Pseudohydrosme bogneri, and conclude that it is Critically Endangered (Possibly Extinct) using the IUCN 2012 standard. Pseudohydrosme bogneri appears to be the tenth documented probable global extinction of a plant species that has occurred among the narrowly endemic plant species of the Libreville area, Gabon.

plant biology↗

bioRxiv2021

Kupeantha yabassi (Coffeeae- Rubiaceae), a new Critically Endangered shrub species of the Ebo Forest area, Littoral Region, Cameroon

A new species to science of evergreen forest shrub, Kupeantha yabassi (Coffeeae - Rubiaceae), is described, illustrated, mapped, and compared morphologically with the closely similar species K. pentamera. Restricted so far to a single site in evergreen lowland forest near the Ebo Forest, Yabassi, Littoral Region, Cameroon, this species is Critically Endangered using the IUCN 2012 standard due to habitat clearance driven mainly by agriculture, adding to the growing list of threatened species resulting from anthropogenic pressure on Cameroon forests. A revised key to the six species of Kupeantha is presented. Two distinct geographical and ecological species groupings within the genus are identified and discussed. Notes are given on other narrowly endemic and threatened species in the Ebo forest area, a threatened centre of diversity important for conservation in Littoral Region.

plant biology↗

bioRxiv2020

Deinbollia onanae (Sapindaceae), a new, Endangered, montane tree species from the Cameroon Highlands.

Deinbollia onanae (Sapindaceae-Litchi clade) is here formally named and characterised as a new species to science, previously known as Deinbollia sp. 2. Cameroon has the highest species-diversity and species endemism known in this African-Western Indian Ocean genus of 42 species. Deinbollia onanae is an infrequent tree species known from five locations in surviving islands of montane (or upper submontane) forest along the line of the Cameroon Highlands. It is here assessed as Endangered according to the IUCN 2012 standard, threatened mainly by clearance of forest for agriculture. The majority of tree species characteristic of montane forest (above 2000 m alt.) in the Cameroon Highlands are also widespread in East African mountains (i.e. are Afromontane). Deinbollia onanae is one of only a very small number of species that are endemic (globally restricted to) the mountain range. It is postulated that this new species is in a sister relationship with Deinbollia oreophila, which is a frequent species of a lower (submontane) altitudinal band of the same range. It is further postulated that seed dispersal is or was by frugivorous birds, potentially turacos, alternatively by primates such as Preuss s monkey.

plant biology↗

bioRxiv2020

Taxonomic revision of the threatened African genus Pseudohydrosme Engl. (Araceae), with P. ebo, a new, Critically Endangered species from Ebo, Cameroon.

This is the first revision in nearly 130 years of the African genus Pseudohydrosme, formerly considered endemic to Gabon. Sister to Anchomanes, Pseudohydrosme is distinct from Anchomanes because of its 2-3-locular ovary (not unilocular), peduncle concealed by cataphylls at anthesis and far shorter than the spathe (not exposed, far exceeding the spathe), stipitate fruits and viviparous (vegetatively apomictic) roots (not sessile, roots non-viviparous). Three species, one new to science, are recognised, in two sections. Although doubt has previously been cast on the value of recognising Pseudohydrosme buettneri, of Gabon, it is here accepted and maintained as a distinct species in the monotypic section, Zyganthera. However, it is considered to be probably globally extinct. Pseudohydrosme gabunensis, type species of the genus, also Gabonese, is maintained in Sect. Pseudohydrosme together with Pseudohydrosme ebo sp.nov. of the Ebo Forest, Littoral, Cameroon, the first addition to the genus since the nineteenth century, and which extends the range of the genus 450 km north from Gabon, into the Cross-Sanaga biogeographic area. The discovery of Pseudohydrosme ebo resulted from a series of surveys for conservation management in Cameroon, and triggered this paper. All three species of Pseudohydrosme are morphologically characterised, their habitat and biogeography discussed, and their extinction risks are respectively assessed as Critically Endangered (Possibly Extinct), Endangered and Critically Endangered using the IUCN standard. Clearance of forest habitat for logging, followed by agriculture or urbanisation are major threats. One of the species may occur in a formally protected areas and is also cultivated widely but infrequently in Europe and the USA for its spectacular inflorescences.

plant biology↗

bioRxiv2020

Nepenthes maximoides (Nepenthaceae) a new, Critically Endangered (Possibly Extinct) species in Sect. Alatae from Luzon, Philippines showing striking pitcher convergence with N. maxima (Sect. Regiae) of Indonesia.

ABSTRACTNepenthes maximoides sp. nov. (Sect. Alatae) is described and assessed as Critically Endangered (Possibly Extinct) from Luzon, Philippines and appears unrecorded in 110 years. The spectacular, large, narrowly funnel-shaped upper pitchers, lids with recurved basal, and filiform apical appendages, unlike any other species in the Philippines, closely resemble those of N. maxima (Sect. Regiae) of Sulawesi-New Guinea, likely due to convergent evolution. Following recent phylogenomic analysis, sect. Alatae is divided into two, Sect. Alatae sensu stricto of Luzon to Sibuyan (including N. maximoides), and Sect. Micramphorae, expanded and recircumscribed to encompass those species of the southern Visayas, and Mindanao. A key is provided to the six species now recognised in the narrowly recircumscribed Sect. Alatae. The number of Nepenthes species recorded from Luzon has increased from two in 2001, to eight in 2020, all but one of which are endemic to that island, and four of which appear to be point endemics.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗

bioRxiv2020

A synoptic revision of Pohliella (Podostemaceae) with notes on Aulea, Cipoia and Saxicolella.

Saxicolella Engl., an African genus of the waterfall specialist plant family Podostemaceae, was shown to be polyphyletic as currently delimited. One clade, sampled from species in Ghana, is sister to American Ceratolacis (Tul.)Wedd., Podostemum Michx. and all Old World Podostemoideae (podostemoids). The second clade, sampled from Cameroonian material, was embedded within the major clade of African podostemoids. In this paper the generic nomenclature applied to Saxicolella sensu lato (Saxicolella, Pohliella Engl., Aulea Lebrun & Stork nom. inval.), is reviewed and the morphological support for the two clades and their correct generic names is determined. Pohliella is shown to be the correct name for the first clade (based on Pohliella laciniata Engl., Cameroon) and a synoptic treatment of its three published species is given, one of which is extinct, and two are threatened. However, a fourth, unpublished species exists. The new combinations Pohliella submersa (J.B.Hall) Cheek and Pohliella amicorum (J.B. Hall) Cheek are made for the two published Ghanaian species. The recently described New World genus Cipoia C.T. Philbrick, Novelo & Irgang is revealed as being morphologically identical to Pohliella, but in view of the geographical disjunction, confirmation from molecular evidence is awaited before its two species are also transferred to Pohliella. The correct name for the second clade, embedded in African podostemoids, is Saxicolella (sensu stricto), now with two known species, Saxicolella nana Engl. (type of Saxicolella, Cameroon) and Saxicolella flabellata (G.Taylor) C. Cusset (Nigeria).

plant biology↗

bioRxiv2020

An analysis of Species Conservation Action Plans in Guinea

To achieve conservation success, we need to support the recovery of threatened species. Yet, <5% of plant species listed as threatened on the IUCN Red List have Species Conservation Action Plans (CAPs). If we are to move from a Red List to a Green List for threatened plant species, CAPs need to be devised and implemented. Guinea is one of the most botanically diverse countries in West Africa. Recent research found that nearly 4000 vascular plants occur in Guinea, a 30% increase from previous estimates. 273 of these plant species are now assessed as threatened with global extinction. There is increasing pressure on the environment from the extractive industry and a growing population. In parallel with implementation of an Important Plant Area programme in Guinea, CAPs were developed for 20 threatened plant species. These plans elaborate conservation efforts needed first to safeguard threatened species both in situ and ex situ and then to support their recovery. We document the approach used to assemble the Species Conservation Action Plans, and we discuss the importance of having up to date field information, IUCN Red List assessments, and use of a collaborative approach. The need for these plans is increasingly important with recent calculations suggesting a third of African plants are threatened with extinction. This paper outlines initial detailed plant conservation planning in Guinea and offers a template for conservation practitioners in other tropical African countries to follow.

ecology↗

bioRxiv2019

A classification of functional pitcher types in Nepenthes (Nepenthaceae).

We classify Nepenthes species into 12 functional pitcher types, based on combinations of traits that appear to comprise different syndromes for capturing nutrients, usually from animals. For nine of these types the trapping syndromes are already documented, six targeting live animals (hence carnivorous), and three targeting other nutrient sources (non-carnivorous). Yet, for three pitcher types here is no previous documentation of the syndrome and we do not yet know what sources of nutrients are being targeted. Mapping all these pitcher types on the latest, near comprehensive species-level phylogenomic tree of Nepenthes (Murphy et al. 2019) shows that apart from the ancestral pitcher type 1, most of the remaining pitcher types have evolved independently, in different parts of the phylogenetic tree, usually in several different places. Each of the 12 pitcher types is characterised morphologically and illustrated, its trapping syndrome discussed, and example species are given. An identification key to the 12 pitcher types is presented. The possibility of additional pitcher types being present is discussed. O_FIG O_LINKSMALLFIG WIDTH=96 HEIGHT=200 SRC="FIGDIR/small/852137v1_fig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@bbfa57org.highwire.dtl.DTLVardef@13084e7org.highwire.dtl.DTLVardef@658770org.highwire.dtl.DTLVardef@19eca44_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOType 1 (Fig. 1).C_FLOATNO Ancestral (N. mirabilis) These species have upper pitchers which are more-or-less ovoid-cylindric in shape. The basal, ovoid part, often but not always a little wider than the upper part, is usually separated from the upper, usually cylindrical part by a "hip" or raised ridge that girdles the circumference of the pitcher on the exterior (also present in the six species of pitcher types 7, 8 and 10). Examination of the inner surface shows that the "hip" divides the glossy, broad, basal, fluid-containing, digestive, part (referred to as the "detentive" zone by Macfarlane (1908) because prey are detained here) from the upper opaque, dull, off-white to slightly purple, waxy or "pruinose" zone. This waxy zone is referred to as the "conductive" zone by Macfarlane because it helps conducts the insects downwards to the detentive zone with the digestive fluid. Such type 1 pitchers are shown in Fig. 1, exemplified by the upper pitchers of Nepenthes mirabilis (Lour.) Druce. The waxy zone is so-called because its surface is made up of numerous minute platelets of wax, each platelet like a roof-tile and held on a fragile stalk from the underlying surface. Juniper et al. (1989) documented how the waxy zone functions to prevent animals, usually insects, from leaving the pitchers once they have fallen in. Pressure from a foot placed on a wax "tile" will result in the stalk breaking, so that the insect loses its foothold and may fall back into the pitcher. C_FIG O_FIG O_LINKSMALLFIG WIDTH=111 HEIGHT=200 SRC="FIGDIR/small/852137v1_fig12.gif" ALT="Figure 12"> View larger version (39K): org.highwire.dtl.DTLVardef@1f13b4borg.highwire.dtl.DTLVardef@6bc534org.highwire.dtl.DTLVardef@1600959org.highwire.dtl.DTLVardef@5ee42_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOPitcher type 12. (Fig. 12).C_FLOATNO Flat lip (N. jacquelineae Nepenthes jacquelineae (Sumatra, Sect. Montanae) and N. platychila Ch.C.Lee (Borneo, Sect C.Clarke et al.).. Regiae, Lee 2002) both have all the features of type 3 pitchers: widely funnel-shaped to cup-shaped, non-waxy upper parts of pitchers draining into a more slender cylindrical lower part with viscous liquid. Both species however differ from all type 3 species in their very large, flat, dark red peristomes which can be up to 3.5 cm wide in N. jacquelineae. These peristomes have been speculated to act as a landing platform for large flying insects such as blattid cockroaches and moths, which might act with the contrasting lighter, green pitcher body as a light trap for such prey. It is also possible that such prey are lured into a precarious place above the mouth by the copious nectar produced from the lower surface of the lid from large nectar glands 1.5 mm diam. (Clarke 2001). The morphological convergence between the pitchers of these two species is remarkable. Further investigation of the prey trapped in the wild would be desirable for both species. Nepenthes echinostoma Hook.f. is a species closely related to N. mirabilis but with a remarkably flat and extended peristome which resembles type 3, although it has a different pitcher shape and inner surface C_FIG

plant biology↗

bioRxiv2019

Notes on the threatened lowland forests of Mt Cameroon and their endemics including Drypetes njonji sp. nov., with a key to species of Drypetes sect. Stipulares (Putranjivaceae).

Background and aimsThis paper reports a further discovery of a new endemic threatened species to science in the context of long-term botanical surveys in the lowland coastal forests of Mount Cameroon specifically and generally in the Cross River-Sanaga interval of west-central Africa. These studies focus on species discovery and conservation through the Tropical Important Plant Areas programme.\n\nMethodsNormal practices of herbarium taxonomy have been applied to study the material collected. The relevant collections are stored in the Herbarium of the Royal Botanic Gardens, Kew, London and at the Limbe Botanic Garden, Limbe, and the Institute of Research in Agronomic Development - National Herbarium of Cameroon, Yaounde.\n\nKey resultsNew species to science continue to be discovered from Mt Cameroon. Most of these species are rare, highly localised, and threatened by habitat destruction. These discoveries increase the justification for improved conservation management of surviving habitat. Drypetes njonji is described as an additional species new to science and appears to be endemic to the lowland coastal forests at the foot of Mt Cameroon. It is placed in and keyed out in Sect. Stipulares, a group confined to Lower Guinea. The conservation status of Drypetes njonji is assessed as Endangered (EN B1+2ab(iii)) according to the 2012 criteria of IUCN. An updated overview of the lowland plant endemics of Mt Cameroon is presented.

plant biology↗

bioRxiv2019

Notes on the endemic cloud forest plants of the Cameroon Highlands and the new, Endangered, Tricalysia elmar (Coffeeae-Rubiaceae)

Background and aimsThis paper reports a further discovery in the context of a long-term botanical survey in the Cross River-Sanaga interval of west-central Africa, focussing on species discovery and conservation.\n\nMethodsNormal practices of herbarium taxonomy have been applied to study the material collected. The relevant collections are stored in the Herbarium of the Royal Botanic Gardens, Kew, London and at the Institute of Research in Agronomic Development - National Herbarium of Cameroon.\n\nKey resultsNew species to science continue to be discovered from the cloud (submontane) forests of the Cameroon Highlands in Cameroon. Most of these species are rare, highly localised, and threatened by habitat destruction. These discoveries increase the justification for improved conservation management of surviving habitat. Tricalysia elmar Cheek (Coffeeae-Rubiaceae) is described as an additional species new to science and is compared with similar species of the genus. Restricted so far to four locations, Mt Kupe, Bali Ngemba, Lebialem and Nta Ali, its conservation status is assessed as Endangered (EN B1+2ab(iii)) according to the 2012 criteria of IUCN.

plant biology↗

bioRxiv2019

A phylogenomic analysis of Nepenthes (Nepenthaceae)

Nepenthaceae is one of the largest carnivorous plant families and features ecological and morphological adaptations indicating an impressive adaptive radiation. However, investigation of evolutionary and taxonomic questions is hindered by poor phylogenetic understanding, with previous molecular studies based on limited loci and taxa. We use high-throughput sequencing with a target-capture methodology based on a 353-loci, probe set to recover sequences for 197 samples, representing 151 described or putative Nepenthes species. Phylogenetic analyses were performed using supermatrix and maximum quartet species tree approaches. Our analyses confirm five Western outlier taxa, followed by N. danseri, as successively sister to the remainder of the group. We also find mostly consistent recovery of two major Southeast Asian clades. The first contains common or widespread lowland species plus a Wallacean-New Guinean clade. Within the second clade, sects. Insignes and Tentaculatae are well supported, while geographically defined clades representing Sumatra, Indochina, Peninsular Malaysia, Palawan, Mindanao and Borneo are also consistently recovered. However, we find considerable conflicting signal at the site and locus level, and often unstable backbone relationships. A handful of Bornean taxa are inconsistently placed and require further investigation. We make further suggestions for a modified infra-generic classification of genus Nepenthes.

evolutionary biology↗