Aspidistra sarcantha Aver., Tillich, T.A. Le & K.S. Nguyen, 2019

Averyanov, Leonid V., Le, Tuan Anh, Nguyen, Khang Sinh, Tillich, Hans-Juergen, Nguyen, Danh Duc, Hoang, Le Tuan Anh, Tran, Hoang Dung, Dat, Pham Thi Thanh & Maisak, Tatiana V., 2019, Aspidistra erosa, A. sarcantha, and A. verruculosa (Asparagaceae), three new species from Vietnam, Phytotaxa 404 (3), pp. 102-110 : 107-108

Aspidistra sarcantha Aver., Tillich, T.A. Le & K.S. Nguyen , sp. nov. ( Fig. 2 )

Type: — VIETNAM. Central Vietnam, Quang Tri province, Dakrong district, Dakrong municipality, 16.614583°N 106.863556°E, 150–200 m a.s.l., shady reclined slopes in assemblage with Pachystylidium hirsutum, Tropidia angulosa and Impatiens sp. , flowering in August–September, common, 25 August 2018, Le Tuan Anh, Hoang Le Tuan Anh, LTA 536 (holotype — LE 01048210!; isotype — VNMN!).

Paratypes: — VIETNAM. Northern Vietnam, Ha Tinh province, Cam Xuyen district, Cam My commune, Ke Go Nature Reserve , Ke Go Lake , 18.17400° N, 105.90800° E, at elevation of 100–200 m a. s. l. Secondary evergreen broad-leaved forest on non-limestone forest mountain, terrestrial herb about 50–70 cm tall, fruit dirty black purple, common, 18 June, 2017, Nguyen Sinh Khang et al., NSK 944 a ( HN!) ; herbarium specimens prepared from plant cultivated in Hanoi in K. S. Nguyen garden, collected in Cam Xuyen district, Cam My commune, Ke Go Nature Reserve , Ke Go Lake , terrestrial herb about 50 cm tall, flower black-purple, 22 November 2017, Nguyen Sinh Khang, NSK 944 b ( HN!) ; central Vietnam, Quang Tri province, Dakrong district, Ta Long commune, Dakrong Nature Reserve , 16.60775°N 106.8835°E, shady primary and secondary evergreen broad-leaved lowland forest on karstic limestone hillsides at elevation 200–250 m a.s.l., terrestrial herb on shady slope, common, 18 May, 2017, Le Tuan Anh, Le Thi Xuan, LTA 135 ( LE01048206 !, VNMN!) .

Etymology:—Species epithet refers to fleshy thick keels of the perigone lobes touching each other and forming a fleshy annular-shaped structure that retains a small entrance into the tube.

Description: —Terrestrial perennial rhizomatous herb 40–60 cm tall. Rhizome terete, epigeous to hypogeous, creeping, plagiotropic, much branched; individual branches (2.5)3.0–4.0(5.0) mm in diameter, (0.8)1.0–1.5(2.0) cm long, densely nodal, covered by dissected papyraceous remnants of the cataphylls, with (2)3–4(5) distant erect leaves. Cataphylls convolute, narrowly triangular cuneate, papyraceous, dull grey, (1.0)1.5–3.0(5.0) cm long, withered and partially disintegrated before anthesis. Leaves spaced throughout the apical parts of the rhizomes, petiolate, internodes (3)4–6(8) mm long. Petiole slender, erect, straight, (25)30–35(40) cm long. Leaf blade upright, oblique or almost horizontal, narrowly ovate to elliptic, broadly cuneate at the base, shortly attenuate at the apex, (14)18–24(26) cm long, (5.5)6.5–8.5(9.0) cm wide, uniformly grassy green, with prominent midvein on the lower surface and few inconspicuous secondary veins at both sides. Flowers solitary, pedunculate, not widely opening. Peduncle white to light greenish, sometimes slightly mottled with some purple near the apex, (2.5)3.0–6.0(8.0) cm long, (2.8)3.0– 3.8(4.0) mm in diameter (when fresh), with (3)4–5(6) scattered and (1)2(3) bracts at the base of the perigone; lower bracts broadly ovate, hyaline or papyraceous, white with fine irregular dirty purple markings, roundish to blunt at apex, (5)7–9(10) mm long and wide (being flattened), the distal bracts adpressed to perigone base, broadly triangular-

ovate, concave, (7)8–9(10) mm long and wide, obtuse to subacute, often splitting at the apex. Perigone tube urceolate, (1.6)1.8–2.0(2.2) cm in diameter, (0.6)0.8–0.9(1.1) cm tall, with 6 lobes; outside smooth, white to light greenish, sparsely mottled with dirty purple at the apical half; inside smooth, ridged, very dark purple-violet or almost black. Perigone lobes 6, subsimilar, narrowly triangular, roundish or blunt at the apex, fleshy, with narrow scarious irregularly wavy margin, smooth outside, rough inside, erect, slightly outcurved, with apex bent inward, (8)9–13(14) mm long, (6)7–9(10) mm wide, outside densely purple mottled at the lower half, distal half and margin dark purple, inside dark purple with often pale greenish upper third; each lobe inside with 2 prominent fleshy roughly papillose keels running down to the middle of perigone tube, all keels at level of the tube opening approaching side by side and thus narrowing the tube entrance. Stamens 6; anthers sessile, flat, broadly ovate, cordate at the base, (2.4)2.5–2.8(3.0) mm long, (2.4)2.5–2.8(3.0) mm wide, adpressed to the base of the perigone tube, horizontally spreading with pollen sacs oriented upwards; pollen bright yellow. Pistil mushroom-shaped, with peltate, slightly convex stigma; ovary white, inconspicuous; style stout, white, shortly cylindrical, (1.4)1.5–2.0(2.2) mm tall, (3.7)3.8–4.0(4.2) mm in diameter. Stigma large, fleshy, hexagonal, (1.5)1.6–1.8(2.0) cm in diameter, obscurely 6-lobed, with low radiate ribs between sinuses and convex center, entirely white, heavy marked throughout with dark purple-violet, finely papillose. Fruits on stout ascending the stalk, subglobular, 1.5–2.0 cm in diameter, dark brown to dull purplish-brown, sparsely prickled.

Habitat, phenology and conservation status:—Shady primary and secondary evergreen broad-leaved lowland forests on karstic limestone and non-limestone rocks at elevations 150–250 m a.s.l., usually on declivous slopes in assemblage with Pachystylidium hirsutum, Tropidia angulosa and Impatiens sp. Locally common. Flowering in August–September (cultivated plants flower in November), fruiting in June–August. Since no special surveys were carried out for delimiting its distribution, this species was considered as meeting the criteria of Data Deficient (DD) in terms of IUCN Red list categories and criteria ( IUCN 2017).

Distribution:— Vietnam, Ha Tinh (Cam Xuyen district) and Quang Tri provinces (Dakrong district). Endemic of the central part of Vietnam.

Similar species:— Aspidistra sarcantha is most similar to A. semiaperta Aver. & Tillich (2015: 373) , known ( Averyanov & Tillich 2015, Averyanov et al. 2018b) from northern Vietnam (Hoa Binh province, Lac Son district) and central Laos (Bolikhamsai province, Thaphabat district), but differs clearly in larger flowers, 1.6–2.2 cm in diameter (vs. flowers 1–1.6 cm in diameter), the perigone tube urceolate (vs. perigone tube depressed urceolate), tube outside white to light greenish mottled with purple (vs. tube outside uniformly dark purple), perigone lobes outcurved, longer than wide, inside with 2 tall keels (vs. perigone lobes straight erect or inward directed, wider than long, inside with 2 low insignificant keels) and much longer peduncle, 2.5–8 cm long (vs. peduncle 0.6–1.2 cm long, often flowers subsessile). These differences, together with the certain geographic distance between known area of A. semiaperta and locations of new species in central part of Vietnam are good reasons to recognize a new species.

Figures

FIGURE 2. Aspidistra sarcantha Aver., Tillich, T.A. Le & K.S. Nguyen, sp. nov. (picture of the plate made from LTA 135 & LTA 536). Photos by Tuan Anh Le, correction and design by L. Averyanov and T. Maisak.