A new species of Catha (Celastraceae) from southern Natal and Pondoland

Catha abbottii Van Wyk & Prins, a tree endemic to the southern Natal/Pondoland sandstone region is described. It occurs in ravine forest and is presently known from a small area between the Umtamvuna and Mzamba Rivers. C. abbottii is of phylogenetic significance in combining characters of the other two species of Catha Forssk. ex Scop. In capsule morphology it resembles C. edulis (Vahl) Forssk. ex Endl., the species on which the genus was originally based. Its wingless seeds in particular, but also other characters, suggest a closer affinity to C. transvaalensis Codd, the species on which the genus Lydenburgia N.K.B. Robson (subsequently reduced to the synonymy of Catha) was established. It can easily be separated from C. transvaalensis by its scaly bark, fewer leaf crenations, 4–6 pairs of principal lateral veins, erose-fimbriate petal margins, strongly recurved stamens and oblong capsules with a prominent septal ridge on the inner surface of the valves

Two new species of Apodytes (Icacinaceae) from southern Africa

Apodytes abbottii Potgieter & Van Wyk and A. geldenhuysii Van Wyk & Potgieter, two new species from southern Africa, are described, illustrated and compared with the other African members of the genus. A. abbottii is a shrub or small tree endemic to rocky sandstone outcrops in southern Natal and north-eastern Transkei (Pondoland Centre). It is probably allied to the widespread A. dimidiata E. Mey. ex Arn. subsp. dimidiata, with which its range overlaps. Diagnostic characters of A. abbottii include its robust though often stunted habit, thick and rigid blue-green leaves which are rounded, erect terminal inflorescences and glabrous ovaries. A. geldenhuysii is a rare multistemmed shrub or small slender tree confined to a small area in the mountains of the south-western Cape. It is a very distinctive species without any close relatives. The few-flowered axillary racemes, unusual pale green and translucent colour of the ripe fruit appendage, intercellular pectic protuberances in the mesophyll of the leaf lamina, and fibres (in addition to sclereids) in the secondary phloem, immediately distinguish it from all other African members of the genus. Other diagnostic characters include the relatively small ovate to ovate-elliptic leaves with retuse apices, blunt-tipped cylindrical flower buds, glabrous ovaries and narrowly oblong off-white petals which are strongly recurved with markedly incurved apices

A taxonomic revision of Elaeodendron Jacq. (Cassinoideae: Celastraceae) in Africa

The heterogeneous genus, Cassine L. s.l. is subdivided into smaller, more natural genera, following new evidence from macromorphology, palynology and anatomy. Elaeodendron Jacq., one of the segregate genera, is here revised for Africa. The redefined genus Elaeodendron is cosmopolitan, with consists of 30 to 40 species of shrubs and trees distributed in Africa, Asia, Australasia and central America. Eight species of Elaeodendron are recognized in Africa. A new combination, E. transvaalense (Burtt Davy) R.H. Archer (= Cassine transvaalensis) is proposed. The other species are Elaeodendron aquifolium (Fiori) Chiov., E buchananii (Loes.) Loes., E. croceum (Thunb.) DC., E. matabelicum Loes., E. schlechterianum (Loes.) Loes. and E. zeyheri Spreng. ex Turcz. The correct application of the previously misapplied and confused name E. croceum is discussed

Systematic studies in subfamily Celastroideae (Celastraceae) in southern Africa: The genus Putterlickia

The genus Putterlickia Endl. is confined to the moister eastern coastal parts of southern Africa, from the Western Cape in the south to southern Mozambique in the north, with one disjunct species in the arid interior of the Northern Cape. Four species are recognised: P. pyracantha (L.) Szyszyl., P. verrucosa (E. Mey. ex Sond.) Szyszyl., P. retrospinosa Van Wyk & Mostert and P. saxatilis (Burch.) M. Jordaan. The nomenclature, including concise synonymy and typification, descriptions of the genus and species, key for identification, notes on habitat and relationships, history and distribution maps, as well as notes on leaf anatomy are supplied for each species. An illustration of P. verrucosa is provided

Taxonomic position of Rhus problematodes (Anacardiaceae): Evidence from fruit and seed structure

This is the first report on the structure of the pericarp and seed coat of Rhus problematodes Merxm. & Roessl., a curious microphyllous shrublet of very limited distribution in the southern desert region of Namibia. Mainly on the basis of macromorphology, it was hitherto considered to stand somewhat apart from other African members of Rhus L. (sect. Gerontogeae Engl.). R. problematodes clearly agrees with other species of Rhus in its basic pericarp and seed-coat characteristics, including a single-seeded unilocular drupaceous fruit, parenchymatous mesocarp with secretory ducts, ridged outer endocarp, inner endocarp composed of three discrete layers, and an endotegmic, partially pachychalazal seed coat. The scarcity of stomata and heavy deposition of cutin in the exocarp possibly reflect adaptations to its arid habitat. Evidence from fruit and seed structure, combined with that from other sources, reconfirms the view that it is a highly specialized species of Rhus showing several xeromorphic, mainly macromorphological, reductions. The shared presence of glandular stellate hairs and reduced foliage leaves suggests that it might be closely allied to R. horrida Eckl. & Zeyh., a species from Namaqualand

The identity of Pachystigma bowkeri (Rubiaceae, tribe Vanguerieae)

Since its publication the name Pachystigma bowkeri Robyns has not been taken up and various authors suggested that the taxon to which it was applied might be conspecific with P. macrocalyx (Sond.) Robyns. In a recent study of the genus in southern Africa it was established that P. macrocalyx constitutes a heterogeneous taxon. Two species should be recognized with P. bowkeri Robyns being the correct name for one of these. The name P. bowkeri Robyns is therefore reinstated

Floral development in Greyia flanaganii with notes on inflorescence initiation and sympodial branching

The aerial parts of Greyia flanaganii H. Bolus consist of a system of superposed monochasial shoots. The mature lateral inflorescences of this evergreen and probably most primitive species of Greyia Hook. & Harv. are primarily terminal. The flowers are adapted to ornithophily, basically diplostemonous and inclined to haplostemony. The 5 floral whorls essentially develop acropetally and alternately, but in flower buds with less than 10 stamens the carpels are epipetalous. The multilayered endothecium-like tissue and additional inner parenchyma form the criteria for considering the anther of Greyia as phylogenetically primitive. Similarities in floral morphogenesis of the Greyiaceae and Saxifragaceae sensu lato are discussed

Ovule, seed and seedling characters in Acharia (Achariaceae) with evidence of myrmecochory in the family

An investigation of mature seed structure in Guthriea capensis and ovule-to-seed development in Acharia tragodes indicate that the two species are herbaceous myrmecochores with similar adaptations for seed dispersal and germination. The development and structure of the modified seed tissues, namely a sarcotestal elaiosome, a fringe layer in the mesotesta, endotestal-exotegmic mechanical layers and a chalazal seed lid are described. Additional embryological similarities between the two taxa include, amongst others, sessile ovules, distally lobed outer integuments, zigzag micropyle canals formed by both integuments, bisporic Allium Type embryo sacs, suspensorless embryos belonging to the Penaea Variation of the Asterad Type, and small embryos in the mature seed. In Acharia intraseminal embryo growth occurs before radicle emergence, germination is epigeal and seedlings belong to the Macaranga Type