Sipapoantha obtusisepala Lepis, Maas & Struwe, 2011

Sipapoantha obtusisepala Lepis, Maas & Struwe View in CoL , sp. nov. — Fig. 1 View Fig

Sipapoantha ostrinae similis, sed habitu ligneo et ramoso, foliis sessilibus, ovatis,apice acutis,calyce minore, lobis circularibus differt. — Typus: B.G S. Ribeiro 396 ( holotype IAN), Brazil, Roraima, Serra Baeta, perto de Suriname, 11 Nov. 1973. Arbusto sobre pedra; flôr azulada .

Etymology. The name obtusisepala derives from the Latin ‘obtusus’ meaning rounded and ‘sepalum’ meaning sepal. This name was chosen to reflect the obtuse apices of the calyx lobes.

Shrub. Stems woody, branching, with four longitudinal ridges c. 0.1 mm wide. Leaves evenly dispersed along stem, sessile; blade elliptic or ovate towards the apex of plant, 1– 2.5 by 0.5–1.2 cm, upper side more lightly coloured than lower side; base of lower leaves attenuate, base of upper leaves obtuse; apex acute. Inflorescence 5 –12-flowered; peduncles 5.3 –14.5 cm long; bracts scale-like with obtuse apex, 1.9– 2.1 mm long; pedicels 6 –9 mm long (in fruit). Calyx campanulate, 6 –7 mm long, fused 0.4– 0.6 of total calyx length; lobes circular, 3– 4 mm diam; apex obtuse. Corolla not seen, reported as blue ( Ribeiro 396). Stamens not seen. Gynecium not seen in flower. Capsule medially dehiscent, ellipsoid, 10–12 mm long; calyx in fruit c. 0.6 of capsule length, with a semi-persistent style, c. 30 mm long with some apical portions broken off in older capsules. Seeds roughly cubical, 0.2 –0.5 mm diam.

Distribution — Brazilian state of Roraima, in the Brazilian-Guyana border area.

Habitat & Ecology — Sipapoantha obtusisepala is known from only one specimen growing among rocks on the Sierra Baeta mountain .