Peliosanthes separata Vislobokov, 2016

VISLOBOKOV, NIKOLAY A., 2016, Peliosanthes separata (Asparagaceae), a new species from Laos with rare structure of androecium, Phytotaxa 275 (2), pp. 186-188 : 186-188

Peliosanthes separata Vislobokov , sp. nov. ( Fig. 1 )

Similar to P. stellaris , but style shorter, tepals wider, petiole shorter and lamina larger.

Type: — LAOS, Vientiane province, Vang Vieng district, 3.5 km W from Vang Vieng town, around the point 18° 55’ 57.6’’ N, 102° 24’ 41.1’’ E, alt. 300 m, forest, at the bank of temporary stream, 12 Dec 2015, N.A. Vislobokov 15052 ( MW) .

Herbaceous perennial evergreen plant. Rhizome short plagiotropic or ascending, Ø 2.5 –3.5 mm. Cataphylls papyraceous, purplish, up to 7 cm long. Roots grey, Ø 2–3 mm. Foliage leaves dark green, erect, petiolate ( Fig. 1a ). Petiole rigid, adaxially sulcate, 14.5–19.5 cm long, Ø 1.5 mm. Lamina elliptic, basally cuneate and distally acuminate, 13.5–14.5 cm long, 4.1–4.6 cm wide, glabrous, with 2 secondary veins at both sides of the midvein ( Fig. 1b ). Inflorescence a raceme, 8 cm tall; scape erect or ascending, 3 cm long, Ø 2–2.8 mm, with 4–5 greenish, ovate-cuneate, sterile bract, 9–10.5 mm long, 4.5–6 mm wide; rachis 4–5 cm long bearing about 27 flowers ( Fig. 1d ). Floral bracts green to light greenish, scarious, cuneate to narrowly lanceolate, 7.4–9 mm long, 2.4–4.4 mm wide. Flowers solitary, almost completely greenish, articulated with short green pedicel 1.1–1.6 mm long, Ø 0.7 –0.8 mm, with single narrowly lanceolate bracteole 2–2.4 cm long, 0.7 mm wide. Perigone campanulate, 4.3–5 mm long, Ø 5.6 –6.7 mm; tube light green at both sides, widely campanulate, 1–1.9 mm long, Ø 3.5 –4.4 mm; lobes 6, arranged in two whorls, equal, somewhat incurved, light green inside, light green or partly dark grey spotted outside, ovate-triangular acuminate, 3.1–4.2 mm long, 1.8–2.9 mm wide ( Fig. 1e–g ). Stamens 6, at the radii of tepals; filaments light green, fleshy, triangular, almost completely free (somewhat fused at the base, forming stamen ring less 1 mm high, not forming corona), 1.2–1.7 mm long, 1.6–1.9 mm wide near the base; anthers small, yellowish, 0.8–0.9 mm long, introrse. Style dark grey spotted, cylindrical, very short, less 1 mm high ( Fig. 1h, i ). Stigma greenish, flat, 3-lobed, Ø 0.5 mm. Ovary semi-inferior, broadly obconical, 3-locular, 1.2 mm high. Fruits berries, blue (young fruits green), ellipsoidal, 11–13 mm long, Ø 7.3 –8 mm ( Fig. 1c ).

Additional specimens examined: — Living plant in Main Botanic Garden of Russian Academy of Sciences (Moscow), garden number: 2015.11343 01, collection number: VV15PS02, collected from the type locality 12 Dec 2015.

Etymology: — The specific epithet refers to structure of androecium, which consists of six separate stamens without formation of corona, which occurs in most species of Peliosanthes .

Flowering: — Flowering was recorded in early June in greenhouse.

Fruiting: — Fruiting was recorded in December in nature.

Distribution: — The species is known from type locality only. Presumably it is local endemic of northern Laos.

Taxonomic relationships:—The new species resembles P. stellaris Ridl. by the presence of almost separate stamens, which is unique feature for these two species only. Also P. separata resembles P. stellaris by inferior ovary and green color of perigone but differs in shorter style (not ascending stamen ring vs longer that the stamens), shape of tepals (triangularovate vs. narrowly linear), shorter petioles (14.5–19.5 cm vs. 7.6 cm) and lager lamina (13.5–14.5 × 4.1–4.6 cm vs. 12.7 × 2.5 cm).

Figures

FIGURE 1. Peliosanthes separata. a. fruiting plant; b. plant, view from above; c. fruits; d. flowering plant; e, f. inflorescence; g. flower, view from side; h, i. longitudinal section of flower. (Images d–f, h, i provided by M.S. Romanov).