Dorstenia stellaris A. Sant. & Romaniuc, 2012

Santos, Alessandra dos & Neto, Sergio Romaniuc, 2012, A new species of Dorstenia (Moraceae) from southeastern Brazil, PhytoKeys 12, pp. 47-51 : 48-50

Dorstenia stellaris A. Sant. & Romaniuc sp. nov. Fig. 1 A-D Fig. 2

Diagnosis.

Coenanthium ellipticum, irregulariter stellatum et lamina basis cordiformis differt.

Type.

BRASIL. São Paulo, Pindamonhangaba, distrito de Ribeirão Grande, near Fazenda São Sebastião do Ribeirão Grande, 26 Nov. 2011, A. Santos et al. 142 (Holotype: SP!); Brasil. São Paulo, Pindamonhangaba, distrito de Ribeirão Grande, Fazenda São Sebastião do Ribeirão Grande, 30 Mar. 1994, I. Cordeiro et al. 1323 (Paratype: SP!); São Paulo, Pindamonhangaba, distrito de Ribeirão Grande, near Fazenda São Sebastião do Ribeirão Grande, 26 Nov. 2011, A. Santos et al. 143, 144, 145, 146 (Paratype: SP!).

Description.

Camephytes 30-70 cm tall; stems aerial, erect, hirsute to tomentose; internodes 1-2.5 cm long.; latex white and abundant. Stipules 1-2 mm long., subulate, narrowly triangular, ciliate, persistent to deciduous, hairs white. Leaves distichous to whorled; blade 8-12 × 3.5-5 cm, membranaceous, apex long acuminate, base cordate, adaxial side scabrous, hairs sparse, white, abaxial side puberulous to hirsute, hairs gathered on the veins; margins entire to denticulate; petiole 2.5-5 cm long., hirsute; brochidodromous venation; 5-6 pairs of secondary veins; tertiary veins scalariform. Coenanthium elliptic, 1-2 cm diam., pateliform, stellate, 3-5 angulate, puberulous; margin with sessile bracts, 0.5-1 mm long., mostly on the angle apex, puberulous, fringes 0.5-0.7 mm alt., greenish to vinaceous; peduncle 1.5-2.5 cm long., puberulous. Staminate flowers distributed through the whole coenanthium; stamens 2; perianth 2 lobed. Pistilate flowers distributed through the whole coenanthium: perianth short lobed, whit apex minutely 2-3 lobed, puberulous; stigma 0.5-1 mm long., slender, white. Drupes elliptical, endocarp smooth to verrucosus; stigmas persistent. Seeds with a flat testa.

Phenology.

Collected with flowers in march and november, and fruits in march.

Ecology.

Dorstenia stellaris is a camephyte from shady and moist areas within the Atlantic forest, which occur in litter soils, near waterfalls inside forests of the type locality.

Similar species.

The angulate shape of Dorstenia bowmaniana , and Dorstenia carautae coenanthium is similar to that Dorstenia stellaris , however, the differs on the strongly irregularly-stellate coenanthium and on the cordate leaves. Dorstenia milaneziana and Dorstenia setosa are also similar to Dorstenia stellaris by the cordate leaves, however, they differ from Dorstenia stellaris by the rounded coenanthium. The other species of the Lecanium section are mostly orbicular to elliptic coenanthium.

Distribution and conservation status.

As Dorstenia stellaris is a newly described and very restricted taxon occurring in a non-conserved area, it warrants special attention with regard to its conservation status. This species has only been found within its type locality in small populations. We believe, indeed, that this species is endangered and following IUCN (2011) criteria we recommend its classification within the endangered status of conservation (EN).

Etymology.

stellaris epithet refers to the irregularly-stellate shape of the coenanthium.

Figures

Figure 1. Dorstenia stellaris A. Sant. & Romaniuc A habit B ciliate stipule C stellate coenanthium D inflorescence, detail of coenanthium fringes and bracts on the angles of the coenanthium margin. (A. Santos et al. 142).

Figure 2. Dorstenia stellaris inflorescence, detail of coenanthium (photo: A. Santos 2011).