Pentagonia santanderensis (Rubiaceae, Dialypetalantheae) is described and illustrated from the department of Santander, occurring in the municipalities of Cimitarra, La Belleza, and Landázuri in fragmented forests and primary forest edges associated with water sources. We compare this new taxon with morphologically similar species; the size of its leaves, the magenta coloration of the strongly pleated leaf bases, and the color, indumentum, and size of the corolla, as well as the fruits, are diagnostic characters. This new species increases the number of Pentagonia species recorded in Colombia to 23. Based on the IUCN criteria, P. santanderensis is assessed as Endangered (EN B2a(ii)b(iii)) due to its restricted distribution and continuing decline in habitat quality.
Impatiens tanahkaroensis is described here as a new species known from the mountainous regions north of the Lake Toba area, northern Sumatra, Indonesia. It is a rheophytic species growing on a small stream, which is potentially threatened by flash floods. A detailed description, discussion, and living photographs are given.
This issue is dedicated to the 120th anniversary of Webbia’s founding. It is a fitting tribute to a journal that has been and continues to be a point of reference in the history of Plant Taxonomy and Geography in Italy and abroad. The contributions presented here reflect the journal’s international vision, focused on enhancing plant biodiversity in increasingly threatened parts of the World. Thanks go to all the authors present here who responded to my appeal, and for whom I am deeply grateful.
The recently recognised Quadrispina clade within Barleria sect. Prionitis Nees (Acanthaceae) represents a taxonomically challenging group endemic to the Horn of Africa biodiversity hotspot. This study presents a comprehensive taxonomic revision of the complex, driven by morphological assessment and morphometric analyses. We recognise seven species in the complex in total, including four new species to science that had previously been included within B. quadrispina, namely B. filtuensis, B. mudugensis, B. puberulifolia and B. sebsebei. In addition, we recognise four subspecies within B. quadrispina, namely subsp. quadrispina, subsp. glaucobracteata, subsp. waggana and the newly described subsp. kenyana. Conservation assessments based on IUCN Red List categories and criteria indicate that B. filtuensis, B. mudugensis, B. puberulifolia, B. sebsebei and B. quadrispina subsp. glaucobraceata are range-restricted and potentially threatened by habitat degradation, hence they are preliminarily assessed as threatened under criterion B, whilst B. quadrispina subsp. kenyana remains Data Deficient.
Plagiosiphon intermedium Burgt, Ngansop & Tchiengué, Leguminosae–Detarioideae, is described and illustrated. It is a tree, to 34 m high, with a stem to 66 cm diameter. The leaves have (2 –)3–4(– 5) pairs of opposite leaflets, with the lowest pair often sub-opposite. The flowers are unknown. The fruit is a pod, brown, the valves more or less obovate in outline, 7–9.5 × 3.5–4.5 cm, without visible veins outside, short dense hairy outside. Plagiosiphon intermedium occurs in primary rain forest, at 760–870 m elevation. The tree species is endemic to the Ngovayang Massif in the South Region of Cameroon. Three herbarium collections have been made, in an extent of occurrence of only 0.51 km2. Plagiosiphon intermedium is provisionally assessed as Endangered B1(iii,v)+B2(iii,v).
The Burseraceae in Ethiopia comprises six species of Boswellia and 42 of Commiphora, producing frankincense or myrrh. This work aims to study the distribution and ecology of all 48 species, although some Commiphora-species are poorly documented. Boswellia species form two distinct geographic groups: one northwestern and one southeastern. Most Commiphora species are confined to the southern and eastern lowlands, with a few also occurring in river valleys in highlands. Distributions are analysed against vegetation types and climate models. Ranges vary from widespread in climatically suitable areas to highly localized. Commiphora species are linked to Acacia-Commiphora bushland on limestone and sand (mostly calcareous), though specific ecological preferences are still unclear. Species richness on degree squares correlates with collection intensity, indicating gaps in knowledge beyond well-sampled areas. Assessed IUCN categories of extinction risks range from Least concern to Critically endangered.
To investigate the evolutionary relationships among 23 species in the Cotteinae we generated a DNA sequence-derived phylogeny utilizing three plastid (rps16-trnK spacer, rps16 intron, rpl32-trnL spacer) regions and the nuclear ribosomal internal transcribed spacer (ITS) region. The Bayesian tree provides strong support for the monophyly of the Cotteinae and its four genera, in order of divergence: Cottea, the Kaokochloa + Schmidtia clade, and the Enneapogon clade. Since the Eragrostideae clearly evolved from African ancestors and Kaokochloa, Schmidtia, and Enneapogon all share species from Africa, we hypothesize the ancestral area of Cotteinae to be Africa. Within Enneapogon we recovered four major clades, the first two splits with species primarily from Africa and the third split containing a basal species from Africa/Asia/Europe sister to all species from Australia. The ancestral area of Enneapogon is Africa and based on our current sample the 13 species from Australia appear to be derived from a single dispersal event from an ancestor shared with E. persicus.
A taxonomic revision of Lasiacis (Griseb.) Hitchc. 47 years since the last contribution (Davidse 1978) is proposed here. Historical and recent collections across 35 herbaria have been examined. Typifications are confirmed or emended, and 8 lectotypes are here designated (see Appendix III). Vernacular nomenclature and economic and therapeutic uses are updated based on bibliographic data or on information from herbarium specimens. For each taxon examined, an iconograph supporting the main diagnostic characters is proposed. Taxa previously described as varieties, such as L. divaricata var. austroamericana, L. rugelii var. pohlii, and L. ruscifolia var. velutina are elevated to the rank of species, and L. acuminata Swallen has been resurrected as a valid species, recognizing a total of 22 taxa, 18 species and 4 varieties.
Currently 39 species of Ardisia are recognised from continental Africa, of which three (A. sadebeckiana Gilg, A. schlechteri Gilg, and A. ebo Cheek, each endemic to Cameroon and known from a single collection) are herbaceous, with creeping, horizontal, rooting herbaceous stems, the stem apex more or less ascending to up to c. 10 cm tall above the ground (decumbent). These species lack the distinctive plagiotropic (perpendicular and horizontal) aerial reproductive stems seen in most woody Ardisia species of Africa (instead sporadically producing rooting ascending stems from the horizontal stem) and have distichous leaves (not spiralled as in most species in Africa). Accordingly, they are proposed as a separate subgenus Kamardisia. Study of herbarium material revealed that six additional species exist which are described and illustrated in this paper, together with preliminary conservation assessments. These are: A. hansii (South Region, Cameroon and Belinga, Gabon), A. massaha (Belinga, Gabon), A. chaillu, A. minuta, A. waka (all Chaillu Massif, Gabon), A. ngounie (Ogooué-Maritime, Gabon). We provide a key to the identification of the nine herbaceous species, provide preliminary conservation assessments for each, and notes on shared characteristics of the African herbaceous species including the taxonomic value of leaf microcharacters (oil glands and trichomes). We also make a preliminary report on the possibility of bacterial colonisation of marginal leaf pores in some of these herbaceous species. All of the species are range restricted, the most wide-ranging with only three sites. All but one species is threatened, and almost all of those are Critically Endangered (provisional assessments). The two first published species have not been seen for more than 125 years, despite being in easily accessible, well-botanised locations, and are both feared extinct. We discuss actions to attempt to refind these species and safeguard the remainder.
In this study, we provide a comprehensive and updated overview of the biogeographic history of several Brazilian phytogeographic domains: the Amazon Rainforest, Brazilian Atlantic Forest, Caatinga, Cerrado, Pampa, and Pantanal. We also outline the main hypotheses that were proposed to explain the distribution patterns and endemism of taxa within these domains. The tropical forests, specifically the Amazon Rainforest and the Brazilian Atlantic Forest, were likely continuous during the Eocene optimum. However, global cooling and increased aridity in the late Eocene and part of the Oligocene led to the fragmentation of these extensive tropical forests. This fragmentation resulted in the creation of the dry diagonal, which includes the Cerrado, Caatinga, Pantanal, and Chaco regions. The dry diagonal served as a geographic barrier, promoting the formation of the Brazilian Atlantic Forest to the East and the Amazon Rainforest to the West. Despite this barrier, forest corridors likely existed between these domains, playing a crucial role in the segregation of the Caatinga from the Cerrado. The Caatinga is the most recent of these domains, having formed in the early to mid-Holocene. The lineages characteristic of the Cerrado likely diversified between the Miocene and early Pliocene.
Recently it became clear that at least some of the varieties and subspecies that are currently recognised in Bakerella Tiegh. (Loranthaceae) from Madagascar are better placed as species. In several cases these taxa were originally already described as species but not yet in Bakerella, so new combinations are needed. The first four new combinations are published here.
The complex nomenclature of the Cuban endemic palm Copernicia macroglossa Schaedtler is revisited. The research involved looking into six validly published names and resulted in a revision of the lectotypification of C. ×macroglossa H.Wendl. ex Becc. (accepted name C. ×escarzana León) and a reevaluation of previous typification accounts for C. ×escarzana León, C. ×burretiana León, and C. torreana León.
We provide a synopsis of the African genus Heterotis (Melastomataceae), recognising seven species and including the description of a species new to science Heterotis kupensis Sv. & Cheek (Melastomataceae) known only from Mt Kupe in the South West Region of Cameroon. It differs from all other members of the genus by its tardily caducous, oblong calyx lobes; hastate pedoconnectives on the antesepalous stamens with transversely ellipsoid ventral appendages; the hypanthium covered by hairs with thickened bases as well as filiform appendages on the upper half only; sessile leaf-blades and the yellow centre to the flower. In addition, we select lectotypes for H. prostrata (Thonn.) Benth. and H. fruticosa (Brenan) Ver.-Lib. & G.Kadereit, a second step lectotype for H. buettneriana (Cogn.) Jacq.-Fél. and designate the new name H. welwitschii (Cogn.) Sv. & Cheek to replace the illegitimate H. cogniauxiana (A.Fern. & R.Fern.) Ver.-Lib. & G.Kadereit. Morphological species delimitation between H. decumbens, H. prostrata, and H. rotundifolia is difficult and intermediate specimens are common. Heterotis rotundifolia is widely reported as naturalised and invasive, however many occurrences from outside of mainland Africa actually represent H. prostrata or have intermediate morphology. Heterotis decumbens has been introduced and naturalised in Madagascar and the Mascarene Islands. Distribution, habitat, phenology, taxonomic notes, and preliminary conservation assessments following IUCN Red List criteria are presented along with a key to the species.
Two new species of Keetia are described from recent botanical collections for conservation management made in surviving submontane forest areas of the sandstone plateau areas of the Republic of Guinea. Keetia kounounkan Cheek & Simbiano is a shrub of the Kounounkan Plateau towards the border of Sierra Leone, so far with a single location in gallery forest. K. tinka Cheek & Simbiano is an evergreen rainforest climber of the main part of the Fouta Djalon Highlands with two locations both in degraded forest. Both species are described, illustrated and provisionally assessed for their conservation status, the first as Critically Endangered, the second as Endangered.
During recent botanical expeditions in the northwestern Saudi Arabia, Sarga purpureosericea Spangler was recorded and collected for the first time in the country. This finding enriches Saudi Arabia’s grass flora and highlights the importance of further botanical exploration. We formally include this species in the national flora, supported by a voucher specimen deposited at the University of Porto Herbarium (PO). This record bridges a significant biogeographical gap between eastern Africa and the Indian subcontinent. Additionally, we provide a second-step lectotypification of the name. The original lectotypification, based on specimens housed at the Kew Herbarium (K) and the Missouri Botanical Garden Herbarium (MO), constitutes a first-step designation under Article 9.17 of the ICN. We now designate a second-step lectotype that aligns more precisely with Spangler’s original intent.
Chamaegastrodia reiekensis, a holomycotrophic orchid from Northeast India (Mizoram) is described and illustrated as a new species. It is compared with its closely allied species Chamaegastrodia guidongensis, which although similar in morphology and mycoheterotrophic nature can be distinguished by the presence of slender rhizome, compact sheathing scales, floral bracts equalling or exceeding the ovary in length, larger sepals and petals with more dilated hypochile and distinctly sinuate mesochile margin. A key to species for the genus Chamaegastrodia is also incorporated. The conservation status of the newly described species is also provisionally assessed here as Critically Endangered (CR) according to International Union for Conservation of Nature (IUCN) Red List Categories and Criteria.
Schlegelia nelcyiae, from the remnants of wet Amazonian forests in Colombia is described, illustrated, and compared with its similar species. This new species is a hemiepiphytic liana, that shares several morphological features with S. brachyantha. However, it can be differentiated from this species in the shape of the leaves, inflorescence type, calyx, and corolla shape, size, and color. An updated key to the species of Schlegelia is presented. The present contribution increases to 25 the number of Schlegelia species, 18 of them known from Colombia, the country with the highest diversity of the genus.
A new species of Cordia (Cordiaceae) is described, Cordia rosangelae J.I.M.Melo, hitherto recorded exclusively in the Brazilian semiarid region. It can be readily recognised by its subcylindrical branches and, mainly, by its lax inflorescences, flowers with an obclavate calyx distinctly smaller than the corolla tube with a reddish stripe in the apical portion, corresponding to the extension of the lacinia, as well as by its corolla up to 5.0 cm long, unguiculate corolla lobes, flattened style, linear, with calluses stigmas and pyriform ovary. A distribution map with known occurrence records as well as data on the habitat, morphological diagnostic characters and reproductive phenology of the species are provided. A key to distinguishing C. rosangelae from the other species of Cordia sect. Gerascanthus from Caatinga domain is presented. In addition, the conservation status of C. rosangelae is preliminary assessed according to IUCN criteria and the species has been classified as Least Concern (LC).
Coccoloba is one of the richest tropical tree genera of Polygonaceae. Since the last taxonomic treatment of the genus in 1959, new species and new nomenclatural arrangements have been published in the last decade. In this work, Coccoloba ruizii and Coccoloba queretaroensis are described and illustrated as two new endemic species from Mexico. The names Coccoloba browniana, Coccoloba petenensis and Coccoloba wercklei are resurrected based on morphological characters. In addition, to stabilize the taxonomy in Coccoloba barbadensis, neotypes are proposed for the names Coccoloba barbadensis var. mexicana and Coccoloba leptostachya.
We describe and illustrate Anthurium reubarbarum López-Flor., Edwin Trujillo & A.Hay, a new species of sect. Belolonchium (Schott) Engl. from the Department of Huila in Colombia. The definition of sect. Belolonchium is briefly commented upon. The new species is distinguished diagnostically from the similar A. melampyi Croat and A. matabanchoyae A.Hay & M.Llano, and compared with two other Belolonchium species occurring in geographic proximity to the new species.
