A new species of Paranecepsia (Euphorbiaceae-Acalyphoideae) from Madagascar and its relationships among the ‘ alchorneoids clade’ Author Barberá, Patricia Africa & Madagascar Department, Missouri Botanical Garden, P. O. Box 299, 63166 - 0299, St. Louis, Missouri, USA. Meise Botanic Garden, Nieuwelaan 38, B- 1860 Meise, Belgium. Herbarium et Bibliothèque de Botanique africaine, CP 265, Université Libre de Bruxelles, Boulevard du Triomphe, B- 1050 Brussels, Belgium. Real Jardín Botánico (RJB), CSIC, Plaza de Murillo 2, 28014, Madrid, Spain. pbarbera@mobot.org Author Lachenaud, Olivier olivier.lachenaud@plantentuinmeise.be Author Riina, Ricarda rriina@rjb.csic.es text European Journal of Taxonomy 2022 2022-08-08 834 22 37 http://dx.doi.org/10.5852/ejt.2022.834.1895 journal article 118434 10.5852/ejt.2022.834.1895 6836120f-3190-4991-a2b1-2852c6b30f0f 2118-9773 6981018 Genus Paranecepsia Radcl. -Sm. Kew Bulletin 30: 684 ( Radcliffe-Smith 1975 publ. 1976), here amended . Type species Paranecepsia alchorneifolia Radcl. -Sm., Kew Bulletin 30: 684 ( Radcliffe-Smith 1975 publ. 1976). Description Dioecious shrubs to medium-sized trees up to 15 m high, very ramose with Terminalia -like branching (Aubréville’s model); bark greyish. Indumentum of simple trichomes. Buds perulate. Stipules subulate, tardily caducous. Leaves deciduous, alternate, spirally arranged, clustered near apices of twigs and interspersed with bud scales, simple, petiolate, stipellate or not; vernation involute; leaf blade oblanceolate to elliptic, shallowly serrate or crenate-serrate with glandular teeth; venation pinnate, midrib prominent above, lateral veins 10–16 pairs, tertiary veins scalariform to reticulate; domatia present as hairy tufts in the axils of the secondary veins; basilaminar glands present or absent. Inflorescences racemose (strongly reduced in P. andrafiabensis sp. nov. ), axillary, solitary; the staminate ones with 1–5 flowers per bract; the pistillate ones with 1–2 flowers; bracts small, subulate. Staminate flowers with pedicel articulate; calyx closed in bud, later splitting into 3–5 valvate lobes which become reflexed; petals absent; stamens 20–40, glabrous, with filaments free, anthers 2-locular, dorsifixed, introrse, thecae pendulous and longitudinally dehiscent, connective not enlarged; receptacle subglobose; disk glands free, interstaminal, numerous, forming a raspberry-like structure; pistillode absent. Pistillate flowers long-pedicellate; pedicels articulate; sepals 5, free, slightly unequal, elliptic to obovate, entire, foliaceous and prominently veined, green, persistent and slightly accrescent in fruit; petals 5, free, alternisepalous, linear to oblanceolate, entire, glabrous, similar in colour and texture to the sepals but much smaller and with hardly prominent venation; staminodes 1–10, sometimes absent; disc annular to slightly undulate, glabrous; ovary sessile, 2 or 3 locular, with strigose indumentum; ovules 1 per locule; styles bifid, connate at base, persistent; stigmas shortly frimbriate. Fruits capsular, 2 or 3 lobed, pubescent, dehiscent in 2 or 3 bivalved mericarps (cocci); endocarp thinly woody; columella persistent. Seeds globose, smooth, ecarunculate and exarillate, testa plain brown or mottled, hilum ellipsoid to narrowly oblong. Key to the species of Paranecepsia 1. Leaves with petioles 0.2–0.8 cm long and stipels 2.5–5 mm long; staminate inflorescences up to 9 cm long; pistillate flowers with sepals 5–9 mm long; ovary 3-locular; fruits 5–6 × 10 mm ; seed coat plain brown ........................................................................ Paranecepsia alchorneifolia Radcl. -Sm. ‒ Leaves with petioles 0.6–2.6 cm long and stipels (if present) 1–2.2 mm long; staminate inflorescences up to 1.3 cm long; pistillate flowers with sepals 9–15 mm long; ovary 2-locular; fruits 7–8× 13 mm ; seed coat mottled ............................ Paranecepsia andrafiabensis Barberá & O.Lachenaud sp. nov.