Threatened Habitats and Tropical Important Plant Areas of Guinea, West Africa.
Abstract and Figures
Guinea has more than 250 documented unique and threatened plant species, more than is known for any other country in West Africa. To protect them should be not only a national priority but a global one.
Among these species – these natural resources – are the potential for new medicines, materials, and foods that could improve the livelihoods of Guineans through research and development.
However, time is running out. Already 35 of Guinea’s rarest plant species are possibly extinct,
and 25 of these species are, or were, globally unique to Guinea. These species have not been found in more than 50 years, despite our surveys to seek them, and appear to have been destroyed unknowingly as a result of human activities.
Guinea will continue to develop, with increased mining, improved agriculture, new roads, new industry, larger towns and cities, and more infrastructure to support them. This future development will impact on the natural environment.
In this book, we document Guinea’s most threatened habitats for plants, the 22 most important areas for the conservation of these habitats, and the threatened plant species that they contain. If the 22 Tropical Important Plant Areas (TIPAs) that are mapped in this book
can be protected, much of Guinea’s national patrimony in terms of wild plant resources will be safeguarded. Altogether, these 22 areas occupy 8,702km², 3.5% of the surface area of Guinea. Several of these areas are already protected, such as Nimba and Ziama. Others are not protected, such as Kounounkan, which has more globally unique species than any other location in Guinea, yet where forest destruction continues. The 22 TIPAs that are mapped in this book include:
–– Over 60% of Guinea’s threatened plant species
–– Guinea’s most species-rich documented sites
–– Important indigenous socio-economic species
–– The highest quality areas of each of the nine threatened habitats.
We hope that this book, a joint product of Guinean and UK-based scientists, government officials, and NGO staff, will result in increased protection and better management of Guinea’s
plant diversity.
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... Among the specimens collected during botanical surveys aimed at establishing Important Plant Areas in the Republic of Guinea (henceforth Guinea; Couch et al. 2019;Darbyshire et al. 2017) was a new species of Virectaria Bremek. (Rubiaceae: Sabiceeae) found on the Benna Plateau and Mont Kouroula in the prefectures Forécariah and Kindia respectively. ...
... Of the 22 Important Plant Areas (IPAs) in Guinea (Couch et al. 2019), five are in the sandstone table mountains area. Although Virectaria stellata does not occur in any of these five IPA's, one of the three localities where the species is found, is on Mont Kouroula, located in the buffer zone of the Mont Gangan IPA area (Couch et al., 2019). ...
... Of the 22 Important Plant Areas (IPAs) in Guinea (Couch et al. 2019), five are in the sandstone table mountains area. Although Virectaria stellata does not occur in any of these five IPA's, one of the three localities where the species is found, is on Mont Kouroula, located in the buffer zone of the Mont Gangan IPA area (Couch et al., 2019). The Benna Plateau contains two of the three localities where Virectaria stellata occurs, is rich in rare plant species, and should be considered for designation as an IPA. ...
Virectaria (Sabiceeae-Cinchonoideae-Rubiaceae), is a morphologically isolated genus of tropical African herbs or subshrubs, occurring from Senegal to Tanzania. Virectaria stellata, a new species from Guinea, is published. It is a perennial herb, with stems becoming creeping and rooting, to 60 cm long. Virectaria stellata has stellate hairs, recorded here for the first time in the family Rubiaceae. We hypothesize that the stellate hairs of this species result not from mutation but from horizontal gene transfer (HGT) from an Acanthaceae, most likely Barleria, due to their common and perhaps uniquely shared microstructure. We briefly review literature on the control of the transition from simple to stellate hairs and on HGT in plants. Virectaria stellata is found in Forécariah and Kindia Prefectures in the Republic of Guinea. A Virectaria specimen without stellate hairs but otherwise similar to V. stellata was collected in Guinea, about 90 km to the North of the northernmost V. stellata collection. This specimen may represent a possible progenitor of V. stellata. The identification of this specimen requires further study. Virectaria stellata occurs in fissures in vertical sandstone rock at altitudes of 450 to 910 m, in sun or half-shade. An overview of sandstone endemic plant species in the vicinity of the new Virectaria is provided. No threats have been observed, therefore, Virectaria stellata is provisionally assessed here as Least Concern (LC).
... Named for Denise Molmou, leading Guinea field botanist with the National Herbarium of Guinea and Simfer S.A. who discovered and collected the flowering type specimen material in November 2021. Her commitment and actions for the conservation of threatened species of Guinean plants as part of the Guinea TIPAs project (Couch et al. 2019) has been exceptional. She is also commemorated by the endemic, Critically Endangered (Possibly Extinct) Saxicolella deniseae Cheek (Podostemaceae, Cheek et al. 2022b) for which she collected the type and sole specimen. ...
... Designating and implementing Important Plant Areas (Darbyshire et al. 2017;continuously updated) is key to in situ conservation of plant species. For this reason, the Important Plant Areas (TIPAs) of Guinea have been recently designated (Couch et al. 2019) and accepted for incorporation into the national protected area network by the Government of Guinea (Col. Seyba, head of Oguipar (protected areas) pers. ...
... 2019). Fortunately, the major population of Keita deniseae occurs within the newly designated Southern Simandou TIPA (TIPAs Guinea-Conakry (2016 -2019); Couch et al. (2019). Making a conservation action plan (e.g. ...
We show that the two continental African species previously ascribed to the genus Anacolosa , differ in so many architectural, floral and vegetative characters from the remaining species of the genus (which occur from Madagascar to the western Pacific, including the type) that they clearly represent a separate genus. The African genus represented by these two species is unique within the Olacaceae s.l. (excluding Erythropalaceae) in being a climber (vs shrubs or trees in Anacolosa sensu stricto). Climbing in the two African species is achieved by perennial hook-like structures formed by a combination of five separate traits each of which is unknown elsewhere in the Olacaceae s.l. We formally delimit, describe and name this new African genus as Keita . Placement is tentatively in Aptandraceae but confirmation by molecular studies is required. We describe a new species from Guinea as Keita deniseae sp. nov . and transfer the Central African (Democratic Republic of Congo (DRC), Republic of Congo & Gabon) species from Anacolosa to the new genus as Keita uncifera comb. nov. Keita deniseae is assessed using the IUCN (2012) criteria as Endangered due to the threat of clearance or degradation of forest habitat for mining and agriculture, while K. uncifera is assessed as Least Concern in view of its large range, number of locations and low levels of threat. We review the discovery of Keita deniseae in the light of other recent discoveries of new taxa in both Simandou and the Republic of Guinea.
Keetia magassoubiana Cheek, an evergreen rainforest climber, is described and illustrated from the Republic of Guinea, Sierra Leone, Liberia and Ivory Coast. Previously indicated as being close to, but different from, K. tenuiflora (Hiern) Bridson, it differs in the glossy, black, glabrous, epidermis of the distal stem internodes; the first internode rarely with very sparse, red adpressed hairs (vs epidermis pale white-brown, with dense, pale yellow, spreading hairs); abaxial leaf surfaces with domed domatia with a central aperture (vs domatia absent or obscure); secondary stem leaf bases acute (vs obtuse to truncate); bracts forming a laciniate sheath on the distal peduncle (vs two opposite triangular bracts) and the pyrene surface honeycombed with pits (vs entire). The species was earlier included within Canthium multiflorum (Schum. & Thonn.) Hiern, now K. multiflora (Schum. & Thonn.) Bridson, in the Flora of West Tropical Africa , second edition. An updated key is presented to the 16 species of the genus from West Africa. Keetia magassoubiana is provisionally assessed using the IUCN standard as Endangered [EN B1ab(iii)] due to only five of the recorded 14 locations having extant forest habitat, and because of ongoing threats of habitat clearance, mainly for agriculture but also for mining.
Keetia gordonii sp. nov. (Rubiaceae - Vanguerieae) a new species of forest liana from Gabon, is described and illustrated. The new species shows all the diagnostic characters of Keetia , such as pyrenes opening by an apical cap and seeds with tanniniferous endosperm, both of which are unrecorded in other genera of the tribe, flowers with a long-exserted style and erect anthers and a (usually) climbing habit. However, it is unique in the genus for its corolla with dense, appressed, brown hairs externally (vs glabrous or with a few hairs towards the apex), its glabrous disk (vs variously pubescent) and its seeds with a continuous tanniniferous layer in the outer part (vs with tanniniferous areas forming radial bands, or diffuse). Keetia gordonii is assigned to the Keetia hispida group of Guineo-Congolian African species. It is the first endemic Keetia species to be described from Gabon, although several others are awaiting description. On current evidence, the species appears to have six locations and is threatened by forest clearance. It is provisionally assessed using the IUCN (2012) standard as Vulnerable [VU B2ab(i,ii,iii,iv,v)].
The International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species is regarded as the primary source of global extinction risk for species. Despite this importance, the IUCN has assessed less than 20% of the world′s estimated 400,000 flowering plants due to issues like insufficient data or a lack of experts. Thousands of conservation status assessments were generated recently in response to the call to action by the revised Target 2 of the Global Strategy for Plant Conservation (GSPC), “An assessment of the conservation status of all known plant species, as far as possible, to guide conservation action.” Accelerated extinction risk assessments are needed to identify species that are most at risk of extinction, which can then be thoroughly evaluated by the Red List assessment procedure. The land area in the Pacific Islands is significantly smaller than in other parts of the world. Plant species restricted to these islands may be identified as “At Risk” due to the limited land area of these islands, despite being widespread locally. Distribution and abundance data of single-island endemic plant taxa of Kosrae, Federated States of Micronesia, are analyzed and combined with digital elevation model files from this island, ArcGIS, and herbarium data, to calculate the percentage of land area that is available within a species′ elevational occurrence, a metric we have coined the Extent of Inhabitable Elevation of Island Occurrence (EIEIO). This metric can be used as a streamlined system to rapidly identify species that need plant conservation attention and allows for a swifter response to Target 2 of the GSPC.
Keetia nodulosa Cheek, a cloud forest climber nearly endemic to Cameroon, with a single record from Nigeria, is described and illustrated. It is remarkable as the first known species to be recorded with bacterial leaf nodules (BLN) in the genus Keetia, and also, in the tribe Vanguerieae. Other genera in Rubiaceae with BLN are Psychotria (Psychotrieae-Rubioideae), Sericanthe (Coffeeae) and Pavetta (Pavetteae), both Ixoroideae/Dialypetalanthoideae. The BLN in Keetia (Vanguerieae) are illustrated for the first time here. The characteristics and significance of bacterial leaf nodulation in Keetia nodulosa are discussed in the context of rapidly growing knowledge on the subject in flowering plants. Keetia nodulosa is provisionally assessed using the 2012 IUCN standard as Endangered (EN B2ab(iii)). The importance of its conservation, and options for achieving this are discussed in the context of recent extinctions of other plant species in Cameroon. This discovery of a new cloud forest species is discussed in relation to other cloud forest plant species described in the last twenty years which are also distributed over the highlands of the western half of Cameroon.
This study presents a checklist of plants occurring in the Serra do Mucambo (SM), in the municipality of Conceição do Coité, which is included in the Sisal identity territory within the Caatinga phytogeographic domain in the northeastern part of Bahia state. The vegetation of SM is characterized as Deciduous Forest, surrounded by pastures and sisal plantations, historically neglected in floristic surveys. Our fieldwork was conducted from 2010 to 2022, with sampling during both dry and rainy seasons. The specimens collected were incorporated at ALCB, HUEFS and HURB herbaria. We listed 365 species, 273 genera, and 98 families. Angiosperms represented 307 species, 236 genera, and 75 families, followed by Bryophyta and Marchantiophyta (47 species, 28 genera and 18 families), Lycophytes and ferns (11 species, 9 genera, and 5 families). Our data shows high floristic richness in SM, when compared with other areas within the Caatinga domain, including a new record of Orchidaceae for Brazil; four new occurrences for this domain; and eight species endemics to Bahia state. This area includes 354 native species to Brazil, while only 11 are introduced or naturalized, characterizing the SM as an important Caatinga remnant. SM is also one of the few remnants of native vegetation in the Sisal region, being home to endangered, rare, and endemic species, several of them useful for humans, justifying the investment in effective policies for conservation of the area.
Descriptions and illustrations are presented for three new species to science, Vepris udzungwa Cheek , V. lukei Cheek (both Udzungwa Mts, Tanzania), and V. robertsoniae Q.Luke & Cheek (SE Kenyan kaya forests), in the context of a synoptic taxonomic revision and with an identification key to all the known unifoliolate taxa of Vepris in continental Africa. The new species are described and illustrated, while the remaining 10 taxa are given skeletal taxonomic treatments (lacking descriptions). One widespread species in montane eastern Africa is renamed as V. simplex Cheek because its previous name, V. simplicifolia (Engl.) Mziray, is predated by V. simplicifolia Endl. (basionym of Sarcomelicope simplicifolia (Endl.) T.G.Hartley, a widespread species of Australia, Lord Howe and Norfolk Islands, and of New Caledonia). The new combination Vepris hanangensis var. unifoliolata (Kokwaro) Cheek is made. Full or provisional conservation assessments are presented for all species using the IUCN 2012 standard. Of the 13 taxa, nine are considered threatened or near threatened, of which one is Near Threatened, three are Vulnerable, two Endangered, and three Critically Endangered, with two of the latter, both of the Uluguru Mts of Tanzania, possibly extinct globally, although not yet assessed on the IUCN Red List.
Tephrosia kindiana , a new plant species from Guinea, is described and illustrated. It is a shrub 90 – 120 cm tall, multi-stemmed from the base. The leaves have 5 – 13 oblanceolate leaflets; the inflorescence consists of solitary flowers in the leaf axils, or 2 – 3-flowered fascicles; the flowers are orange and 24 – 26 mm long. The species occurs in wooded grassland on sandstone plateaus at 300 – 420 m elevation. Three localities are known, at up to 13 km apart. Tephrosia kindiana is provisionally assessed as Endangered.
Guinea-Conakry has one of the highest plant diversities in Sub-Saharan West Africa and is part of the Upper Guinean Forest ecoregion and the Guinean Forests of West Africa biodiversity hotspot. Guinea is a major supplier of the world’s bauxite and has significant reserves of high grade iron ore, it also has small reserves of diamonds, gold and uranium. As a result large areas of open cast mining exist in the country and pressure on habitats and vegetation are increasing with the need to bring revenue into the country; this is in addition to unsustainable slash and burn agriculture and a growing population. An initial list of 482 was drawn up from the Flore de Guinée, subsequent discussion and screening reduced the list to 253 which is presented here. It is estimated that c. 10% of the countries flora is threatened. Rediscoveries and new species are being made in Guinea, but they are often already threatened having been discovered as part of Environmental Impact Assessments. A comprehensive red list of threatened species is much needed to support the country’s environmental policy as well as their international obligations.
Vepris verdoorniana (Rutaceae) has long been regarded as a widespread and variable species occurring from Guinea to Gabon. Recent evidence has shown that the original material from the type locality in Cameroon consists of two different species, V. verdoorniana in the strict sense, endemic to Lower Guinea (Cameroon, Gabon and C.A.R. in W-C Africa) and V. letouzeyi Onana, which was thought to occur from Guinea to Cameroon. In this paper we show that the West African (Upper Guinea) material previously referred to as V. letouzeyi/V. verdoorniana is separate morphologically from that in Cameroon (Lower Guinea). In fact the West African material referred to comprises two distinct species, here described as V. occidentalis Cheek & Onana (Guinea to Ghana, but probably extending to Benin) a tree of lowland marginal dry evergreen and semi-deciduous forest, and V. fer Cheek, a species restricted to four mainly lower submontane forest locations on iron substrates in Liberia and Sierra Leone (also Upper Guinea). Vepris occidentalis is here assessed as Least Concern due to its wide range and high frequency, whilst V. fer is assessed as Endangered due to the low number of locations and threats from iron ore mining projects. Both new species are illustrated and mapped.
Tropical Africa's first Red Data book for plants. Cameroon contains tropical Africa's most species-diverse hotspots for plants; many are rare and threatened with extinction. This book documents 815 threatened species, using IUCN global assessments, most assessed for the first time. Short species descriptions are given to aid identification in the field, along with notes on habitats and threats. Distribution maps and conservation management suggestions are also provided.
Keetia susu Cheek and K. futa Cheek from the Republic of Guinea, and K. abouabou Cheek from Ivory Coast are described here. Each species is assessed using the IUCN standard as, respectively, Vulnerable, Endangered and Critically Endangered. Each species is illustrated and mapped. A key to the 16 species of Keetia in West Africa (Senegal to Benin) is provided. The number of species of Keetia currently accepted is now known to total 35.
Lebbiea grandiflora (Podostemaceae), a rheophytic herb from the Sewa River rapids in Sierra Leone, is described as a new species. It is the first new African genus of Podostemaceae published for 30 years. First collected in May 2017, the species is assessed as Critically Endangered using the IUCN 2012 standard. It is on the edge of extinction with a small population at a single site threatened by deposition of gravel and sand from alluvial gold and diamond mining upstream, and a planned hydro-electric dam. The new genus is unique in Podostemaceae in a) its highly developed and robust style-stigma structure in which the bases of the two style-stigmas unite to form a bifurcate funneliform-cylindrical structure, with a reflexed, blade-like apex that extends half-way around the perimeter of the ovary-fruit towards the base of the ovary-fruit, b) a specialised andropodium, with robust, self-supporting capacity, having differentiated thickened central, and angled, thinner marginal areas (in other Podostemaceae the andropodial structures are undifferentiated), c) the pillar-like haptera which completely elevate the crustose root above the substrate. Lebbiea is placed in Podostemoideae, necessitating amplification of the delimitation of that subfamily in which it is additionally unique in having the foliose tepals characteristic of the basal subfamilies Weddellinoideae and Tristichoideae.
Guinea-Conakry has one of the highest plant diversities in Sub-Saharan West Africa and is part of the Upper Guinean Forest ecoregion and the Guinean Forests of West Africa biodiversity hotspot. Guinea is a major supplier of the world’s bauxite and has significant reserves of high grade iron ore, it also has small reserves of diamonds, gold and uranium. As a result large areas of open cast mining exist in the country and pressure on habitats and vegetation are increasing with the need to bring revenue into the country; this is in addition to unsustainable slash and burn agriculture and a growing population. An initial list of 482 was drawn up from the Flore de Guinée, subsequent discussion and screening reduced the list to 255 which is presented here. It is estimated that c. 10% of the countries flora is threatened. Rediscoveries and new species are being made in Guinea, but they are often already threatened having been discovered as part of Environmental Impact Assessments. A comprehensive red list of threatened species is much needed to support the country’s environmental policy as well as their international obligations.
Talbotiella cheekii Burgt, a new tree species from Guinea, is described and illustrated. It is a tree to 24 m high, with a stem diameter to 83 cm, and occurs in forest dominated by tree species of the Leguminosae subfamily Detarioideae, on rocky stream banks and rocky hill slopes, at an altitude of 100 – 600 m. It is estimated that 1600 – 2400 mature trees have been seen, in about twelve forest patches; more trees may be present in places not yet visited. One of the localities of the new species is situated at only 46 km northeast of the centre of the capital Conakry and 6 km northeast of the town centre of Coyah, part of the Conakry urban agglomeration. Its distribution is 1400 km further west from the previous westernmost distribution of the genus. The current extent of occurrence is 166 km2. Talbotiella cheekii is here assessed as Endangered (EN) following IUCN Red List categories.
A new genus Kindia (Pavetteae, Rubiaceae) is described with a single species, Kindia gangan, based on collections made in 2016 during botanical exploration of Mt Gangan, Kindia, Republic of Guinea in West Africa. The Mt Gangan area is known for its many endemic species including the only native non-neotropical Bromeliaceae Pitcairnia feliciana. Kindia is the fourth endemic vascular plant genus to be described from Guinea. Based on chloroplast sequence data, the genus is part of Clade II of tribe Pavetteae. In this clade, it is sister to Leptactina sensu lato (including Coleactina and Dictyandra). K. gangan is distinguished from Leptactina s.l. by the combination of the following characters: its epilithic habit; several-flowered axillary inflorescences; distinct calyx tube as long as the lobes; a infundibular-campanulate corolla tube with narrow proximal section widening abruptly to the broad distal section; presence of a dense hair band near base of the corolla tube; anthers and style deeply included, reaching about mid-height of the corolla tube; anthers lacking connective appendages and with sub-basal insertion; pollen type 1; pollen presenter (style head) winged and glabrous (smooth and usually hairy in Leptactina); orange colleters producing a vivid red exudate, which encircle the hypanthium, and occur inside the calyx and stipules. Kindia is a subshrub that appears restricted to bare, vertical rock faces of sandstone. Fruit dispersal and pollination by bats is postulated. Here, it is assessed as Endangered EN D1 using the 2012 IUCN standard. High resolution LC-MS/MS analysis revealed over 40 triterpenoid compounds in the colleter exudate, including those assigned to the cycloartane class. Triterpenoids are of interest for their diverse chemical structures, varied biological activities, and potential therapeutic value.
Despite the severe threats to plant habitats and high levels of extinction risk for plant species in many parts of the world, plant conservation priorities are often poorly represented in national and global frameworks because of a lack of data in an accessible and consistent format to inform conservation decision making. The Important Plant Areas (IPAs) criteria system offers a pragmatic yet scientifically rigorous means of delivering these datasets, enabling informed national- or regional-scale conservation prioritisation, and contributing significantly towards global prioritisation systems including the International Union for Conservation of Nature Key Biodiversity Areas (KBAs) Standard. In this paper, we review the IPA rationale and progress on IPA identification to date, including the perceived limitations of the process and how these may be overcome. We then present a revised set of criteria for use globally, developed through the combined experiences of IPA identification over the past decade and a half and through a recent global consultation process. An overview of how the revised IPA criteria can work alongside the newly published KBA Standard is also provided. IPA criteria are based around a sound, scientific, global framework which acknowledges the practical problems of gathering plant and habitat data in many regions of the world, and recognises the role of peer reviewed expert opinion in the selection process. National and sub-national engagement in IPA identification is essential, providing a primary route towards long term conservation of key sites for plant diversity. The IPA criteria can be applied to the conservation of all organism groups within the plant and fungal kingdoms.