Neobertiera micrantha Delprete, 2015

Delprete, Piero G., 2015, Revision of Neobertiera (Rubiaceae, Sipaneeae) with observations on distyly, and three new species from the Guianas, Phytotaxa 206 (1), pp. 118-132 : 123-124

1. Neobertiera micrantha Delprete , sp. nov. ( Figs. 1 , 2).

Type:— FRENCH GUIANA. Commune de Camopi , Upper Oyapock River Basin , Roche Touatou, small creek in forest, S slope of Mont Touatou, herb 0.5 m tall, stem hirsute, reddish-brown, erect, with age becoming decumbent and rooting at basal nodes, inflorescence terminal, corolla white, 2°57’N, 52°32’W, 120 m, 22 May 1995 (fl, fr), G. Cremers & J. J. de Granville 14097 (holotype, CAY 079885 ; isotypes, CAY 079886 , L, MO not seen, NY, P, US) .

Perennial herbs, 0.5 m tall, erect or basally decumbent, sparsely branched; branches densely appressed strigose; horizontal portion of stem rooting at basal nodes and internodes. Stipules ovate to broadly ovate, 4.5 − 6 × 4 − 5 mm, bifid at apex; each lobe ca. 2 mm long, appressed-strigose. Leaves petiolate; petioles 4 − 10(− 1.5) mm long, sparsely appressed-strigose; blades narrowly elliptic, elliptic to ovate, 4.5 − 9 × 1.5 − 3.5 cm, acute-decurrent at base, acute to obtuse at apex, chartaceous, drying dark olive-green to brown above, pale olive-green to olive-green below, sparsely adpressed short-strigose above, glabrous to sparsely sericeous below, midvein and secondary veins densely strigose above, densely strigose-sericeous below; secondary veins 8 − 11 each side of midrib. Inflorescences always subcapitate (during and after anthesis); peduncles 1.5 − 2 cm long; rachis thin, appressed white-pubescent; flowering portion capitate (extremely reduced cyme); bracts subtending the head lanceolate, 2 − 3 × 1 − 2 mm; bracteoles subtending each flower, linear-lanceolate, 1 − 1.5 × 0.2 − 0.5 mm, glabrous, margins appressed-strigose. Flowers 5-merous, pedicellate; pedicels thin, 0.5 − 1.3 mm long. Hypanthium obovoid, ca. 0.5 mm long, adpressed strigose. Calyx lobes lanceolate, slightly unequal, 1.5 − 2.2 × 0.3 − 0.5 mm, adpressed strigose outside. Corollas hypocrateriform, white, 3.9 − 4.2 mm long; tube narrowly cylindrical, 3 − 3.2 mm long, sparsely appressed-sericeous outside, densely pubescent inside (hairs microscopically moniliform), with a narrow line of sparse, yellow, moniliform hairs at mouth inside; lobes 5, ovate, 0.9 − 1.0 × 0.5 − 0.6 mm, round at apex, glabrous on both sides. Long-styled flowers: stamens inserted at 0.9 mm from the base of corolla tube; filaments 0.4 mm long; anthers narrowly sagittate, 0.7 × 0.2 mm; style about the same length as the corolla tube (branch tips barely exserted), 3 − 3.2 mm long, glabrous; style branches elliptic, 0.3 mm long, densely long-papillose when receptive. Short-styled flowers unknown. Fruits 1.2 − 1.5 mm diam., sparsely strigose-sericeous. Seeds ca. 0.3 − 0.4 mm long, pale brown, microscopically foveolate (barely visible at 50× magnification).

Distribution and ecology ( Fig. 2):—Known only from the type specimens, collected near Mount Touatou, Upper Oyapock River Basin, French Guiana, near a small creek, in the undercanopy of primary forest, at 120 m altitude.

Phenology:—Specimens with flowers and fruits were collected in May.

Suggested conservation status: —Known by a single collection from the remote site of Mount Touatou, Upper Oyapock River Basin, French Guiana. The number of individuals of this population was not reported by the collectors. Therefore, due to the remote locality and the unknown number of individuals of the population, this species is here treated as “Data Deficient” (DD) following IUCN criteria ( IUCN 2001).

Etymology: —The specific epithet refers to the minute flowers of this species, which are the smallest ones in the genus.

Figures

FIGURE 1. Neobertiera micrantha. A. Habit. B. Node with stipule. C. Flower in anthesis. D. Dissected long-styled flower, with stamens inserted at lower portion of the corolla tube. Drawn from Cremers & Granville 14097 (CAY). Illustration by Piero G. Delprete.