Summary. The three species of the genus Rhinacanthus Nees occurring in Angola and Namibia are documented, including a full description of the new species R. angolensis I. Darbysh. and an expanded description of the scarce species R. kaokoensis K. Balkwill & S. D. Will. A key to their identification is provided, together with notes on their conservation status and species affinities.

Diversity of wild herbaceous legumes in Southern Africa, their associated root nodule bacteria, and insect pests. In: Climate change and adaptive land management in southern Africa -assessments, changes, challenges, and solutions (ed. by Revermann, R., Krewenka, K.M., Schmiedel, U., Olwoch, J.M., Helmschrot, J. & Jürgens, N.) Abstract: Climate change models predict that most parts of southern Africa including Botswana and Namibia will experience severe water stress and temperature increases as a result of climate change. Wild drought-tolerant nitrogen-fi xing plants with heat-tolerant bacterial symbionts might be a source for mitigation, nutrient-rich grazing grounds, and soil fertility. Herbaceous legumes may be developed into forage plants that are resilient to climate change eff ects. Therefore, the purpose of the study was to assess the diversity of wild herbaceous legumes in the north-western and eastern parts of Botswana, northern parts of Namibia, and Northern Cape of South Africa. They were assessed for nodulation and insect damage, root nodule bacteria were isolated, and some were identifi ed and authenticated on their homologous hosts. In Namibia, rhizosphere bacteria were isolated and characterised. For the fi rst time, it was shown that a wide range of wild legumes in the study area were nodulated.

Petalidium mannheimerae, here described as a new species, is only known from the Gariep Centre of Plant Endemism in southern Namibia and northwestern South Africa. Apparently first collected in 1961, it grows on arid hillsides and in drainage lines. Diagnostic morphological characters for P. mannheimerae include the rigid, cylindrical distal stems, grey-brown or yellow-brown bark, puberulent vegetative parts with sparsely scattered but robust glandular and eglandular trichomes, and the solitary white flowers with the unexpanded part of the corolla tube shorter than the expanded part. A comparison of some of the more prominent features to differentiate Petalidium mannheimerae from its morphologically most similar relatives is provided. Based on IUCN Red List categories and criteria, a conservation assessment of Vulnerable VU D1 is recommended for the new species. Herbarium specimens of P. mannheimerae have long been misidentified as P. parvifolium, a rarely collected species from east-central Namibia and west-central Botswana. Lectotypes are designated for three taxa, namely P. parvifolium, P. parvifolium var. angustifolium (a synonym of P. linifolium), and P. wilmaniae (a synonym of P. parvifolium).

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