A preliminary checklist of the bryoflora of the Taita Hills, Kenya

A checklist of the bryoflora of the Taita Hills (Kenya) containing 168 taxa in 40 families is presented. Whilst previously only 22 mosses and 39 liverworts were recorded for the area, this study extended our knowledge to 85 and 83 respectively. Twenty taxa are newly recorded for Kenya

Ann Birnie: In Memoriam

No Abstract

Woody plant communities of isolated Afromontane cloud forests in Taita Hills, Kenya

In the Taita Hills in southern Kenya, remnants of the original Afromontane forest vegetation are restricted to isolated mountain peaks. To assess the level of degradation and the need for forest restoration, we examined how forest plant communities and their indicator species vary between and within remnant patches of cloud forest. We used ordinal abundance data to compare plant communities in eight forest fragments. We also analyzed data on the diversity and abundance of trees in 57 0.1 ha plots to compare tree communities within and between the largest two of these fragments, Ngangao (120 ha) and Mbololo (220 ha). The extant vegetation of the Taita Hills at landscape scale consists of secondary moist montane to intermediate montane forest. There was a high species dissimilarity between fragments (69%). Variation in species composition coincided with an abiotic gradient related to elevation. At plot level, secondary successional species and species of forest edges were most abundant and most frequent. Inferred clusters of plots almost entirely coincided with the two forest fragments. Indicator species associated with forest margins and gaps were more frequent in the smaller of the two forest fragments, while indicators for the larger fragment were more typical for less disturbed moist forest. Abiotic site variability but also different levels of disturbance determine site-specific variants of the montane forest. Conservation efforts should not only focus on maintaining forest quantity (size), but also on forest quality (species composition). Late-successional rainforest species are underrepresented in the woody plant communities of the Taita Hills and assisting restoration of viable populations of cloud forest climax tree species is urgently needed

Eulophia edwardii (Orchidaceae), a new species from the Pondoland Centre of Endemism in South Africa

Background and aims – Despite the fact that the orchid flora of South Africa is well documented, new species are still being discovered. The identity of an Eulophia subpopulation from near Port Edward in KwaZulu-Natal has been ambiguous. Some thought that it belongs to Eulophia schnelliae, currently considered a synonym of Eulophia macowanii, whereas others were of the opinion that it was potentially a new species. Both hypotheses are investigated here. Material and methods – Plants were studied in the field and herbarium specimens, including types, were consulted. The relevant published literature was revised. Key results – Eulophia schnelliae is confirmed as a synonym of Eulophia macowanii. The Port Edward subpopulation does not match any known Eulophia taxon and is newly described as Eulophia edwardii, endemic to the Pondoland Centre of Endemism. It is only known from one subpopulation of about 200 individuals, which is threatened by urban development. It is, therefore, assessed as Critically Endangered according to Criterion B2ab(i,ii,iii). Conclusion – The newly described species increases the number of Eulophia species in South Africa to 29 and the number of endemic Eulophia species to 10. This discovery underlines the need for continued botanical inventories and protection of sensitive grasslands

Mike Bingham: in memoriam. 4 September 1936–4 January 2019

No Abstrac

Comparative vegetative anatomy and systematics of the angraecoids (Vandeae, Orchidaceae) with an emphasis on the leafless habit

The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings of the endovelamen occurred in several vandaceous genera. Exodermal proliferations and aeration units commonly occurred in both leafy and leafless Vandeae. Cladistic analyses of Angraecinae and Aerangidinae with members of Aeridinae and Polystachyinae as outgroups using 26 structural characters resulted in 20 000+ equally parsimonious trees. Vandeae formed the only well-supported clade in bootstrap analyses and were characterized by having a monopodial growth habit, spherical stegmata, loss of mucilage, and loss of tilosomes

Comparative vegetative anatomy and systematics of the angraecoids (Vandeae, Orchidaceae) with an emphasis on the leafless habit

The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings of the endovelamen occurred in several vandaceous genera. Exodermal proliferations and aeration units commonly occurred in both leafy and leafless Vandeae. Cladistic analyses of Angraecinae and Aerangidinae with members of Aeridinae and Polystachyinae as outgroups using 26 structural characters resulted in 20 000+ equally parsimonious trees. Vandeae formed the only well-supported clade in bootstrap analyses and were characterized by having a monopodial growth habit, spherical stegmata, loss of mucilage, and loss of tilosomes

New and interesting orchid records for Tanzania

The original publication is available at http://www.bioone.org/The orchid taxa Brachycorythis ovata subsp. schweinfurthii, Habenaria arianae and Habenaria disparilis are newly recorded for Tanzania, while Brachycorythis congoensis is newly recorded for the floral region T7. A stable, pure yellow mutant of Disa erubescens is recorded for the first time.Publishers' Versio

Molecular Phylogenetics of Vandeae (Orchidaceae) and the Evolution of Leaflessness

Members of tribe Vandeae (Orchidaceae) form a large, antropical clade of horticulturally important epiphytes. Monopodial leafless members of Vandeae have undergone extreme eduction in habit and represent a novel adaptation to the canopy environment in tropical Africa, Asia, and America. To study the evolution of monopodial leaflessness, molecular and structural evidence was used to generate phylogenetic hypotheses for Vandeae. Molecular analyses used sequence data from ITS nrDNA, trnL-F plastid DNA, and matK plastid DNA. Maximum parsimony analyses of these three DNA regions each supported two subtribes within monopodial Vandeae: Aeridinae and a combined Angraecinae þ Aerangidinae. Adding structural characters to sequence data resulted in trees with more homoplasy, but gave fewer trees each with more well-supported clades than either data set alone. Two techniques for examining character evolution were compared: (1) mapping vegetative characters onto a molecular topology and (2) tracing vegetative characters onto a combined structural and molecular topology. In both cases, structural synapomorphies supporting monopodial Vandeae were nearly identical. A change in leaf morphology (usually reduced to a nonphotosynthetic scale), monopodial growth habit, and aeration complexes for gas exchange in photosynthetic roots seem to be the most important characters in making the evolutionary transition to leaflessness