New records of alien and potentially invasive grass (Poaceae) species for southern Africa

Background: The grasses (Poaceae) of the Flora of Southern Africa (FSA) region (i.e. Botswana, Eswatini, Lesotho, Namibia and South Africa) are relatively well documented, for both native and non-native species. Visiting taxonomic expertise nevertheless reveals new FSA and in-country records, particularly of non-native species. Such records provide an opportunity for improving biosecurity relating to potentially invasive but hitherto undetected non-native Poaceae in the FSA region.Objectives: To improve floristic data for non-native Poaceae occurring in theFSA region.Method: Field collections were made, herbarium collections, databases and relevant literature were studied.Results: New records are presented for non-native grasses that were encountered as locally common populations in the Drakensberg Mountain Centre of Floristic Endemism (DMC, Lesotho and South Africa). Festuca rubra and Agrostis capillaris are newly reported for sub-Saharan Africa and southern Africa and are also the first verified specimens reported for the African continent, with previous reports from northern-most Africa (Morocco, Algeria and/or Tunisia) uncertain. Jarava plumosa, introduced from South America and previously known for the whole of Africa from a single population in the Western Cape, South Africa, is newly reported from the border between the Eastern Cape, South Africa and Lesotho. The ecological implications, including the potential to become invasive, are discussed for each species, with taxonomic notes given to help differentiate them from closely resembling taxa.Conclusion: These new records of alien grass species raise concerns over their potential ecological impact, particularly as they are found in an area of conservation importance. Future efforts to monitor their distribution are of importance.

The Botanical, Chemical and Ethnobotanical Diversity of Southern African Lamiaceae

The Lamiaceae is undoubtedly an important plant family, having a rich history of use that spans the globe with many species being used in folk medicine and modern industries alike. Their ability to produce aromatic volatile oils has made them valuable sources of materials in the cosmetic, culinary, and pharmaceutical industries. A thorough account of the taxonomic diversity, chemistry and ethnobotany is lacking for southern African Lamiaceae, which feature some of the region’s most notable medicinal and edible plant species. We provide a comprehensive insight into the Lamiaceae flora of southern Africa, comprising 297 species in 42 genera, 105 of which are endemic to the subcontinent. We further explore the medicinal and traditional uses, where all genera with documented uses are covered for the region. A broad review of the chemistry of southern African Lamiaceae is presented, noting that only 101 species (34%) have been investigated chemically (either their volatile oils or phytochemical characterization of secondary metabolites), thus presenting many and varied opportunities for further studies. The main aim of our study was therefore to present an up-to-date account of the botany, chemistry and traditional uses of the family in southern Africa, and to identify obvious knowledge gaps.

Crassula ×mortii (Crassulaceae subfam. Crassuloideae), a new natural hybrid between C. perforata and C. rubricaulis from South Africa’s southern Cape

In terms of species-level diversity, the genus Crassula Linnaeus (1753: 282) is by far the most diverse in the Crassulaceae within the Flora of Southern Africa region [Namibia, Botswana, Eswatini (formerly Swaziland), Lesotho, South Africa] (Tölken 1977a, b, 1985). In this region diversity is highest in the Fynbos and Succulent Karoo Biomes, both of which straddle the southern Cape, an area represented in the Western and Eastern Cape provinces.

New records and key to Poa (Pooideae, Poaceae) from the Flora of Southern Africa region and notes on taxa including a diclinous breeding system in Poa binata

Four species of Poa L. are newly reported for sub-Saharan Africa and southern Africa, Poa compressa L., P. iconia Azn., P. infirma Kunth and P. nemoralis L. This is the first report of P. iconia from Africa. Vouchers at PRE of P. bulbosa L. all belong to var. vivipara Koeler, those of P. iconia belong to var. iconia and the one of P. trivialis L. belongs to var. trivialis. Two subspecies are recognised in P. pratensis L.: subsp. irrigata (Lindm.) H.Lindb. and subsp. pratensis. We also designate a lectotype for P. iconia and second-step lectotype for P. leptoclada Hochst. ex A.Rich. and report the first recording of a diclinous breeding system in P. binata Nees. Our account updates the treatment in Identification Guide to Southern African Grasses (Fish et al. 2015) including a key to the taxa and notes on infrageneric taxonomy, DNA subtypes, ecology, chromosome numbers and breeding systems.

A taxonomic treatment of Trisetopsis (Poeae, Poaceae) in southern Africa

Trisetopsis, a genus of temperate C3 grasses, extends from the Arabian Peninsula southwards along the African mountains (temperate Afromontane Region) to sub-Saharan Africa and Madagascar, with a centre of diversity in southern Africa. A taxonomic treatment of Trisetopsis in the Flora of southern Africa (FSA) region is presented. The proposed classification is based on existing and comparative evidence derived from macromorphology, micromorphology, leaf anatomy, DNA sequences and geographical distribution. Fourteen species of Trisetopsis are recognized in the FSA region, all of them endemic to the region. Five of the species are rare; based on IUCN Red List categories and criteria, three species are considered “Vulnerable”, one as “Endangered, and one as “Critically Endangered” and probably “Extinct”. Improved and emended species descriptions, a key to the species, updated distribution maps and illustrations, especially of the spikelets, are provided. Lectotypes are designated for the names Avenastrum longum var. grande and Avena longa (basionym of Trisetopsis longa).

Reinstatement of Dovyalis revoluta (Flacourtieae, Salicaceae), with an updated key to the species of Dovyalis in southern Africa

Dovyalis revoluta, almost since described included in D. zeyheri, is reinstated. This restricted-range endemic from South Africa is compared with other southern African members of the genus, in particular D. zeyheri. Illustrations, photographs, a distribution map and a revised description are provided. Also included is an updated key to the seven currently accepted members of Dovyalis in the Flora of southern Africa region. Dovyalis revoluta belongs to Dovyalis sect. Dovyalis, and has only been recorded from a small area in the province of KwaZulu-Natal near the town of Hluhluwe. Most plants are known from the False Bay Park section of the Isimangaliso Wetland Park, a World Heritage Site. Dovyalis revoluta is clearly distinguished from other southern African members of the genus by having relatively large (ca. 22–25 mm in diam.), subglobose, orange fruit, with the surface minutely and densely papillate and the calyx lobes (tepals) tightly revolute, but not accrescent, after flowering. Furthermore, the vegetative parts are essentially glabrous and the leaves are usually entire and not distinctly three-veined from the base. Domatia are absent. A preliminary population assessment, including an estimate of the sex ratio, was conducted at False Bay Park. Based on IUCN Red List categories and criteria, a conservation assessment of “Critically Endangered” is recommended for this species.

A revision of the family Sematophyllaceae (Bryophyta) in southern Africa

In the Flora of southern Africa area, comprising the countries of South Africa, Namibia, Botswana, Lesotho and Swaziland, the moss family Sematophyllaceae consists of three genera (Trichosteleum, Donnellia and Sematophyllum) and nine species. Core sematophyllous taxa with collenchymatous exothecial cells, long rostrate operculum, linear leaf cells and differentiated alar cells are included in the family. Meiothecium fuscescens is transferred to Donnellia and a new combination made. Sematophyllum wageri is reduced to synonymy under S. brachycarpum and a lectotype is designated for S. dregei. Each species is described and its distribution mapped.

The diversity and multiple uses of southern African legumes

Southern Africa has a rich legume flora comprising 133 indigenous genera and 1620 indigenous species, of which 1059 species (65%) are endemic to the flora of southern Africa region. An additional 128 non-indigenous species have become naturalised, of which 59 are invasive, resulting in 1748 species from 165 genera. There are 22 (17%) endemic genera, one endemic tribe (Hypocalyptieae) and one near-endemic tribe (Podalyrieae, with 122 of the 123 species endemic). The diversity of uses (given as total/indigenous spp.) include food and beverages (127/115 spp.), medicine (338/291 spp.), magic and charms (113/104 spp.), timber (59/55 spp.), firewood (43/31 spp.) and 10 more minor use categories. Regression analyses showed that the levels of endemism in subfamilies and tribes are directly related to the numbers of species but that the number of useful species is not related to species numbers, except for the non-papilionoid subfamilies (all uses) and non-genistoid papilionoids (medicinal uses only). The Phaseoleae and Millettieae showed high residual values in several analyses, indicating that they have been favoured in the selection of useful plants. Diversity in habit and chemistry seems to explain at least partly the use patterns.