Umtiza Sim, Forest Fl. Cape Good Hope: 205. T. 52. 1907.

Figs 13, 14, 15

Type.

Umtiza listeriana Sim

Description.

Small evergreen trees to 12 m or shrubs, branches armed with stout spines that are frequently branched; branches with lateral brachyblasts (Fig. 13A-C). Stipules absent. Leaves paripinnate, alternate, (3) 5-9 (12) pairs of subopposite leaflets, sometimes with a lateral terminal leaflet. Inflorescences panicles, terminal on spur shoots; bracts minute, persistent. Flowers white, small, regular, bisexual, 5-merous or more rarely 4-merous (Fig. 14A, B); hypanthium short; calyx lobes subequal, sometimes one lobe longer; petals equal, free, inserted on hypanthium rim with the stamens; androecium diplostemonous, stamens opposite petals shorter than those alternate with petals; pollen exine perforate; ovary sessile bearing two ovules. Fruit dehiscent along both sutures, subligneous, valves twisting, not pulpy, usually one-seeded (Fig. 13G). Seed ovate with truncate base, compressed.

Chromosome number.

Unknown.

Included species and geographic distribution.

Monospecific ( U. listeriana), from Eastern Cape region, South Africa, primarily along the Buffalo River between East London and King William’s Town (Fig. 15).

Ecology.

Subtropical dry forest, bushland and thicket.

Etymology.

Derived from ‘umthiza’, the African vernacular name for the single species, U. listeriana .

Human uses.

Used locally for medicine and has alleged magical properties, witchdoctors have used sticks of the tree as healing wands; the wood was once used to house propeller shafts in small boats because its oiliness provided constant lubrication (Ross 1977).

Notes.

The genus is monospecific with Umtiza listeriana endemic to the Eastern Cape region of South Africa where the species is endangered and protected. The Umtiza Nature Reserve is named for this species. Cowan and Polhill (1981) treated Umtiza as a member of the Detarieae, but with uncertainty, partially due to the absence of stipules. Typically, intrapetiolar stipules characterise Detarieae and Amherstieae, but their absence in Umtiza made tribal affinity uncertain. Umtiza is most similar to species of Gleditsia in the presence of branched and unbranched thorns derived from lateral shoots. Umtiza differs from the other two genera of the tribe in the presence of only hermaphrodite flowers and fully dehiscent fruits that lack pulp.

Taxonomic references.

Allen and Allen (1981); Ross (1977), with illustration.