Peliosanthes longicoronata Vislobokov & N.Tanaka, 2018

Vislobokov, Nikolay A., Tanaka, Noriyuki, Kuznetsov, Andrey N., Kuzmicheva, Evgeniya A. & Romanov, Mikhail S., 2018, Peliosanthes longicoronata (Asparagaceae), a new species from central Vietnam, Phytotaxa 360 (3), pp. 296-299 : 296-298

Peliosanthes longicoronata Vislobokov & N.Tanaka , sp. nov. ( Fig. 1 )

Morphologically most similar to Peliosanthes teta Andrews (1810: 605) , differing by its solitary, upward-facing flowers each with an upwardly curving stalky floral base and a white, tubular, distally incurved staminal corona.

Type:— VIETNAM, Ha Tinh Province, Vu Quang district, Vu Quang National Park . Collected in nature in August 1999 by A.N. Kuznetsov 1999.13445. The herbarium specimen prepared from a living cultivated plant in November 2017 by M.S. Romanov & N.A. Vislobokov 17001 (holotype MW!) .

Herbaceous evergreen perennial ( Fig. 1a ). Rhizome short, plagiotropic or ascending, Ø 6.1 –7.3 [6.7] mm. Cataphylls purplish, oblong, papyraceous, up to 4.5–7.8 [6.2] cm long. Roots gray, wiry, Ø 2.1 –2.6 [2.3] mm, densely covered with light gray root hairs. Leaves green, ascending or arching, petiolate ( Fig. 1a, b ). Petiole rigid, adaxially sulcate, 10–18 [16] cm long, Ø 1.7 –2.1 [1.9] mm. Lamina elliptic, basally cuneate and distally acuminate, 14–16 [15.2] cm long, 3.2–4 [3.6] cm wide, glabrous, with 7–9 prominent longitudinal veins (including the midvein), crossed sub-perpendicularly with many unbranching transversal veinlets ( Fig. 1b ). Inflorescence a raceme, 36–69 [52] cm tall; scape (peduncle) erect, 24–38 [31.7] cm long, Ø 1.6 –2.3 [2] mm, with 12–14 greenish, lanceolate, sterile bracts (without flowers in axils) 7.5–8.6 mm long, 1.2– 1.5 mm wide; rachis 12–23 [17.5] cm long bearing 26–49 flowers ( Fig. 1a, c ). Floral bracts light green, narrowly lanceolatetriangular or subulate, 2.7–6.9 [4.5] mm long, 0.8–1.4 [1] mm wide. Flowers solitary, facing upward, pedicelate. Pedicel horizontal or subhorizontal. straight, green, 2.7–4.6 [3.9] mm long, at base with single lanceolate or subulate bracteole 1.1–1.5 [1.4] mm long, 0.2–0.4 [0.3] mm wide ( Fig. 1d–g ). Perigone completely light green, funnel-shaped, 3.5–4.5 [4.2] mm long, Ø 6.8 –8 [7.4] mm; basal syntepalous part obconic-crateriform, elongating below like a stalk, 3.6–4 [3.8] mm long, Ø 2.3 –2.8 mm, including the basal stalky part 1.4–2.2 [1.9] mm long, Ø 0.5 –0.7 [0.6] mm in distal part, curving upward; lobes 6, arranged in two whorls, homomorphic, somewhat recurved, narrowly triangular, revolute laterally, 2.3–2.6 [2.5] mm long, 1.2–1.7 [1.5] mm wide. Stamen filaments white, fleshy, fused forming cylindrical corona-like structure 1.3–2 [1.5] mm high, Ø 2.1 –2.6 [2.4] mm; anthers 6, at the radii of tepals, white-yellowish, sessile, dorsally adnate to upper portion of corona, 0.5 mm long, introrse, each anther with two elliptic thecae somewhat divergent and upwardly facing in lower part when dehisced. Style green, cylindrical, ca 1 mm high. Stigma greenish, flat, slightly 3-lobed, Ø 0.5 mm. Ovary semiinferior, globular, 3-locular, 1.3 mm high. Seeds green when young, elliptical, 16.2–16.4 [16.3] mm long, Ø 9.9 –10.6 [10.3] mm ( Fig. 1h ).

Additional specimen examined:— Living plant in Main Botanic Garden of Russian Academy of Sciences (Moscow), garden number: 1999.13445, collected from type locality in August 1999. The herbarium specimen prepared from the living cultivated plant in February 2017 by M.S. Romanov & N.A. Vislobokov 17002 ( MW!) .

Etymology:— The specific epithet refers to the comparatively long staminal corona.

Flowering:— From November to February in a greenhouse.

Fruiting:— April in a greenhouse.

Distribution:— Peliosanthes longicoronata is known only from the type locality. Presumably it is a local endemic of central Vietnam.

Taxonomic relationships: — Peliosanthes longicoronata appears most closely allied to P. teta in having an inflorescence exceeding the leaves, columnar styles, and thecae somewhat diverging and facing upward in the lower part, but differs markedly by the solitary (vs. 1–5 in axils of bracts), upward-facing (vs. horizontal to obliquely upward-facing) flowers with an upwardly curving, basal stalky part of perigone, white, tubular, distally incurved (vs. usually purple, broadly conic) staminal corona, and strongly revolute (vs. not or sometimes weakly revolute) perigone lobes. It also approaches P. tonkinensis Wang & Tang (1936: 83) described based on the specimen B. Balansa 280 (in Herbarium Kew: K000099379!) from northern Vietnam by having thecae facing upward in the lower part, but is distinguishable chiefly by the solitary (vs. 2–3), larger flowers (Ø 6.8 –8 vs. 4.5–5 mm), and higher (1.2–1.7 vs. 0.7 mm), tubular (vs. subtubular-hemispheric) corona. The new species somewhat resembles P. divaricatanthera Tanaka (2004: 157) described from central Vietnam and southern China (Yunnan) by having an inflorescence overtopping the leaves and revolute perigone lobes, but is readily distinguishable by the solitary (vs. 1–3) flowers per bract, longer pedicels (2.7–4.6 vs. 2.5 mm), longer basal stalky part of perigone (1.4–2.2 vs. 0.5–1.2 mm), longer perigone lobes (2.3–2.6 vs. 1.4–2 mm), higher (1.3–2 vs. 0.3 mm) and wider (Ø 2.1 –2.6 vs. 1.5–2 mm) staminal corona, thecae slightly divergent in the lower part (vs. divaricate, upward-facing thecae), and columnar (vs. depressed pyramidal) style.

Figures

FIGURE 1. Peliosanthes longicoronata. a. flowering plant; b. leaf blade, adaxial view; c. inflorescence (the constriction is arrowed); d, e. longitudinal section of flower; f. flower, view from below (the constriction is arrowed); g. flower, view from above; h. seeds emerging from ovary. (Images provided by M.S. Romanov, illustration designed by E.A. Kuzmicheva).