Aspidistra verruculosa Aver., Tillich & D.D. 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 : 108-109

Aspidistra verruculosa Aver., Tillich & D.D. Nguyen , sp. nov. ( Fig. 3 )

Type: — VIETNAM. Southern Vietnam, Lam Dong province, Di Linh district, Gung Re commune, 11.461111°N 108.064167°E, primary broad-leaved, mixed and coniferous forest at elevation 1300–1350 m a.s.l., terrestrial herb on shady slope, not common, 20 December 2018, Nguyen Danh Duc, Le Tuan Anh, LTA 910 (holotype LE01049296 !; isotype VNMN!) .

Etymology:—Species epithet refers to the remarkably verruculose adaxial surface of perigone lobes.

Description: —Terrestrial perennial rhizomatous herb 25–40 cm tall. Rhizome hypogeous, erect to suberect, orthotropic, usually simple, (0.6)0.8–1.2(1.4) cm tall, in lower part densely covered by numerous fleshy straight yellowish roots, at the apex with few dissected fibrous or papyraceous remnants of the cataphylls and (2)3–4 erect close leaves. Cataphylls convolute, tubular, papyraceous, dull brownish or yellowish-grey, (2)3–5(6) cm long, withered and partially disintegrated before anthesis. Leaves arising from the rhizome apex, touching each other, petiolate, internodes 0.5–1.0 mm long. Petiole slender, erect, straight, up to (10)12–16(18) cm long. Leaf blade upright, oblique or almost horizontal, narrowly ovate to elliptic, broadly cuneate at base, shortly attenuate at apex, (14)16–18(20) cm long, (4.0)4.5–5.5(6.0) cm wide, grassy green finely marked with small yellow spots, with prominent midvein on the lower surface and several inconspicuous secondary veins at both sides. Flowers solitary, pedunculate, widely opening, (1.2)1.4–1.6(1.8) cm in diameter. Peduncle ascending or arising horizontally, white and more or less heavily speckled with dirty violet, (0.6)0.8–1.2(1.4) cm long, (2.8)3.0–3.4(3.6) mm in diameter (when fresh), with (2)3–4(5) bracts at the peduncle base and (3)4(5) bracts densely adpressed to the base of the perigone; all bracts broadly ovate, fleshy to papyraceous, dirty purple, roundish to blunt at apex, concave, straight along the margin, (4)5–8(10) mm long and wide (being flattened). Perigone tube widely campanulate bowl-shaped, (0.9)1.0–1.1(1.2) cm in diameter, (6.0)6.5– 7.5(8.0) mm tall, with 6 lobes; outside smooth, dull purple-violet; inside rough to finely verruculose, with no keels or other ornamentations, very dark purple-violet or almost black. Perigone lobes 6, subsimilar, broadly triangular ovate, roundish or blunt at apex, little fleshy, with entire or slightly finely erose margin, smooth outside, finely verruculose or tuberculate inside, recurved and spreading, (2.6)2.8–3.8(4.0) mm long, (3.6)3.8–4.0(4.2) mm wide, outside dark dirty purple-violet, inside very dark purple–violet or almost black, with no keels or any other ornamentations. Stamens 6; anthers sessile, bean-shaped, (1.7)1.8–2.0(2.1) mm long, (1.3)1.4–1.5(1.7) mm wide, attached to the basal part of the perigone tube, faced to the style; pollen pale yellow. Pistil table-shaped, with peltate, slightly convex stigma; ovary purple-violet, inconspicuous; style stout, white, densely speckled with purple-violet marks, shortly cylindrical, (2.6)2.8– 3.2(3.4) mm tall, (1.9)2.0–2.2(2.3) mm in diameter. Stigma large, fleshy, circular in outline, (8.5)9.0–11.0(11.5) mm in diameter, 6-lobed, lobes obtriangular, truncate at the apex with somewhat convex center, laterally more or less densely adpressed to each other or irregularly separated by short incisions, white with light violet along margin, almost smooth to slightly finely papillose. Fruits unknown.

Habitat, phenology and conservation status:—Shady primary evergreen broad-leaved, mixed to coniferous submontane forests on granite, at elevations of 1300–1350 m a.s.l., usually on declivous mountain slopes. Not common. Flowering in November–December. The observations available for the species are insufficient and fragmentary, so that we cannot provide a reliable assessment. Hence, this species should be categorized as DD (Data Deficient) according to IUCN Red List criteria ( IUCN 2017).

Distribution:—Southern Vietnam (Lam Dong province, Di Linh district). The species is probably endemic to a small area within the Di Linh district of Lam Dong province in southern Vietnam (Central Highlands).

Similar species:— Aspidistra verruculosa may be compared to A. revoluta H. Zhou, S.R. Yi & Q. Gao ( Zhou et al. 2016: 281) described recently from central China (Chongqing metropolitan area, Jinfoshan Mountain), but differs in very short erect to suberect orthotropic rhizome 1–2 cm tall densely covered by fleshy roots (vs. creeping plagiotropic rhizome 15–25 cm long with distant sparse wiry roots), (1)2–3 leaves at the apex of individual rhizome (vs. 5–7 leaves spaced along the apical part of the individual rhizome), elliptic leaf blade 4.5–6.5 cm wide (vs. linear leaf blade less than 3 cm wide), perigone lobes uniformly dark violet to almost black, finely verruculose, with no keels (vs. perigone lobes smooth, dirty purple with dull yellow margin and distinct yellowish median keel) and almost flat stigma with straight lobes (vs. stigma strongly convex with downcurved lobes).

Figures

FIGURE 3. Aspidistra verruculosa Aver., Tillich. & D.D. Nguyen, sp. nov. (picture of the plate made from LTA 910). Photos by Danh Duc Nguyen, correction and design by L. Averyanov and T. Maisak.