Andrachne

Hoffmann, Petra, 2000, Revision of Andrachne sect. Pseudophyllanthus (Euphorbiaceae), with the description of two new species from Madagascar, Adansonia (3) 22 (1), pp. 123-133 : 124

ANDRACHNE L. sect. PSEUDOPHYLLAN-

THUS Müll. Arg. In DC., Prodr. 15(2): 233 (1866); Benth. & Hook. f., Gen. pl. 3: 271 (1880); Pax in Engl. & Prantl, Nat. Pflanzenfam. 3(5): 15 (1890); Petra Hoffm., Bot. Jahrb. Syst. 116: 327 (1994). Savia Willd. sect. Maschalanthus (Nutt.) Pax & K. Hoffm. pro parte in Engl., Pflanzenr. 81: 182 (1922); Nat. Pflanzenfam., ed. 2, 19c: 67 (1931) . TYPE. — Andrachne ovalis (Sond.) Müll. Arg. Dioecious , more rarely monoecious shrubs or small trees 1-6 m, young branches terete or

slightly flattened. Indumentum scarce, simple. Stipules persistent. Petiole canaliculate adaxially. Leaves alternate, petiolate, simple, symmetrical, entire, pinnately veined, eglandular, without domatia.

Inflorescences one- to few-flowered, axillary, borne directly in the leaf axils or on short, unbranched (rarely once-branched), leafless axes; pistillate and staminate flowers in separate leaf axils. Flowers pedicellate, 5-merous (rarely 4- or 6-merous). Pedicel articulate at the base. Sepals imbricate, free. Petals much shorter to nearly as long as sepals. Disc extrastaminal, annular, more or less antistaminally lobed; lobes apically more or less emarginated. Stamens antisepalous, filaments fused for about half their length, anthers basifix, latrorse in bud, longitudinally dehiscing, thecae parallel. Pistillode present. Styles bipartite to the base. Stigmas apically dilated. Ovules 2 per locule, anatropous (funicle attachment below micropyle), sharing one obturator.

Fruits capsular, depressed globose, dehiscence septicidal, loculicidal and septifragal; dehiscence of septa in one straight line; exo- and mesocarp separate from the endocarp after dehiscence. Endocarp lignified. Columella persistent, 2.5-6 times longer than the narrowest width, acutely 3-angled, base and apex thickened; perianth, disc and stigmas persistent at fruit maturity. Seeds 2 per locule (rarely one), ecarunculate, roughly ovoid, nearly triangular in cross section, rugose (sculpture reminding of a brain), perichalazal annulus absent to small. Endosperm in mature seeds copious. Cotyledons thin, flat, oriented parallel to the pericarp; radicle terete, much longer than wide.

Three species in Southern Africa and Madagascar.

NOTE. — The breeding system is difficult to establish for the two species described here due to the small number of collections; however, all the specimens examined were either pistillate or staminate. In comparison, A. ovalis was found to be monoecious in a number of specimens and apparently dioecious in the remain- der.