Aspidistra cadamensis (Asparagaceae), a new species from Central Vietnam

1Institute of Tropical Biology, Vietnam Academy of Science and Techology, 85 Trần Quốc Toản road, District 3, Hồ Chí Minh City, Vietnam;
2Ludwig-Maximilians-University, Systematic Botany, Menzinger Str. 67, D-80638 Munich, Germany.
*author for correspondence

The genus Aspidistra Ker Gawler (1822: 628) is represented in tropical and subtropical SE Asia by more than 160 species. It has the highest diversity in southern China and northern Vietnam (Tillich 2005, 2014, Tillich & Averyanov 2012, Vislobokov et al. 2013). In Vietnam, more than 50 species are known: many species have been discovered from the limestone regions in North Vietnam, while about 21 species are found from sandstone forests in Central and South Vietnam (Gagnepain 1934, Bogner & Arnautov 2004, Bräuchler & Ngoc 2005, Averyanov & Tillich 2012, 2013, 2016a, 2016b, Averyanov et al. 2016, Tillich 2005, 2014, Tillich & Averyanov 2008, Tillich et al. 2007, Leong-Škorničková et al. 2014, Vislobokov 2015, Vislobokov et al. 2013, 2014b, 2014c, 2016a, 2016b, Lý & Tillich 2016). During extensive floristic surveys in Central Vietnam in 2016, several interesting specimens of Aspidistra were collected by the first author. The critical examination of these specimens and study of literature for Aspidistra in Vietnam and neighbouring countries allowed to evidence several new taxa, two of which have been recently described: A. averyanovii Lý &
Tillich (2016: 54) and A. parviflora Lý & Tillich (2016: 56). In the present paper, we describe a further new species from Cà Đam mountains, Quảng Ngãi Province, namely Aspidistra cadamensis.

Description of the new species
Aspidistra cadamensis N.S.Lý & Tillich sp. nov. (Fig. 1)
Type:—VIETNAM. Quảng Ngãi Province: Tây Trà District, Trà Trung Commune, Cà Đam mountains, Bà Noong stream, 15°09.344 N, 108°27.723 E, 1.008 m elev., 25 September 2016, Lý Ngọc Sâm and Trương Bá Vương, Lý-818 (holotype VNM!; isotypes P!,
Perennial rhizomatous herb, 50–80 cm tall. Rhizome creeping, unbranched, epigeous, with dense short internodes, 4–10 mm in diameter, dark brown, with many roots, 3–8 mm in diameter. Cataphylls ca. 5, ovate-oblong, up to 11 cm long, the inner ones longer than the outer ones near the base, purple to dark red-purple, whitish towards base, later straw-brown. Leaves solitary, 0.5–1 cm apart, distinctly divided into petiole and lamina; petiole stiff, 19.7–46 cm long, green, ventrally with shallow v-shaped furrow at base, basally 4–6 mm swollen, purple-red to black purple; lamina sometimes with yellowish spots, broadly ovate to elliptic-ovate, slightly asymmetric at base, 22–33 cm long and 7.5–9 cm at widest point, tapering into acuminate apex with a minute spine ca. 0.2 mm long, base cuneate or obtuse, adaxially dark-green, semi-glossy, abaxially light green, semi-glossy, mid vein strongly prominent on abaxial surface, each half of lamina with 4–6 prominent secondary veins, between them 4–8 fine-tertiary nerves with numerous anastomoses, margin almost entire, minutely serrate at apex. Flowers (1‒)2–6, arising from apex of rhizome, obliquely upright to horizontal, 10–11.5 mm long, ca. 15 mm in diameter. Peduncle slender, thin, obliquely upright to horizontal, 1–10 cm long, 1–1.5 mm in diam., purple or black-purple, with 5–7 scale bracts, broadly triangular, 3-veined, abaxially redpurple with whitish spots, adaxially paler, glabrous, margin membranous, translucent white, papery, apex cucullate; 3–4 bracts at base, 2–3 mm long, 3–4 mm wide at base, a single scale at the middle to the upper third, distally with 2–3 subtending bracts, 5.5–7.5 mm long, 5–8 mm wide at base. Perigone tube campanulate, fleshy, 6–7 mm long, 7–8 mm in diam., externally mainly whitish or cream-white with purple or red-purple dots towards the upper third, smooth, semi-glossy at the basal half, internally cream-white at basal half, purple-red toward apex; lobes 6, nearly equal, recurved, fleshy, triangular-ovate, 3.5–4.7 mm long, 3.2–5 mm broad at base, apex obtuse, externally purple-red with whitish spots, glabrous, somewhat verrucose, internally purple-red, margin and apex sometimes whitish, with 2-keels running to the upper third of perigone tube, finely verrucose; tube wall and lobes ca. 0.2 mm thick. Stamens 6, inserted at the basal third of perigone tube, positioned lower than stigma, arranged at the same radii with lobes; anthers
sessile, ovate, 1.4–1.6 mm long, ca. 1 mm wide near the base, yellow, latrorse, thecae separated by whitish connective tissue, without a connective appendage; pollen orange-yellow. Pistil widely obconical, 7–8 mm tall, filling nearly completely the space of tube, ovary indistinct; style stout, shortly cylindrical, ca. 2 mm tall, ca. 1.2 mm in diameter, white; stigma fleshy, 6–7 mm in diameter, composed of three lobes firmly adpressed to each other, with 9–12 teeth at margin corresponding to abaxial ridges, apical surface somewhat concave, white, with irregular radial ridges formed during the flowers aging process, margins and lower part purplish-red, abaxially with 12 longitudinal ridges forming deep furrows in between. Fruiting peduncles stiff, 2.5–10 cm long, 1.5–2 mm in diameter, whitish-purple, tinged green-purple or black-purple. Mature fruits globose-obovoid, 7–9 mm long, to 12 mm in diam., tinged green-purple when young, purple-black when ripe, surface rugose, tuberculate, densely prickly with spines up to 4.5 mm long; seeds wedge-shaped, 6–6.5 mm long, 4–5 mm wide at widest point, whitish.
Distribution and ecology:―Currently known only from the type locality, where many subpopulations of scattered mature clumps of non-flowering, flowering and/-or fruiting plants of Aspidistra cadamensis were rather frequent around Cà Đam mountains. For this reason, we believe that this new species can be considered as locally abundant. It grows on hill slopes composed of sandstone at 830–1000 m elev., under the canopy and near stream of lower primary evergreen broad-leaved forests.
Phenology:―Aspidiatra cadamensis was observed flowering and with mature fruits in later July to later September.
Conservation status:―Data Deficient (DD). Four fairy large populations, with a total of about 500 individuals of the new species were found in a total area of less than 5 km2 in Cà Đam mountains. This area is under the protection of the local authorities of the Department of forest protections in Tây Trà and Trà Bồng Districts, Quảng Ngãi Province, and all recognised populations are more or less stable in their strength. However, human activities by local people as harvesting of timber and non-forest products, especially clearing of forest land for Acacia Mill. (1754: 25), plantations have negative impacts on this species. According to the IUCN Red list criteria (IUCN, 2012), we therefore propose here the conservation status of A. cadamensis as data deficient (DD). Further field work of the area around Cà Đam mountains is needed to understand the situation better and amend the conservation status if necessary.
Etymology:―The specific epithet is named after the locality where this new species was found.
Additional specimens examined (paratypes):―VIETNAM. Quảng Ngãi Province: Tây Trà District, Trà Trung Commune, Vàng Village, Cà Đam mountains, Bà Noong stream,15°09.344′N, 108°27.723′E, 1008 m elev., 25 September, 2016, Lý Ngọc Sâm and Trương Bá Vương, Lý-823 (VNM!); the same locality, 14°09.342′N, 108°27.669′E, 939 m elev., 29 July 2016, Lý Ngọc Sâm and Trương Bá Vương, Lý-786 (VNM!); the same locality, 15°09.260′N, 108°27.528′E, 846 m elev., 29 July 2016, Lý Ngọc Sâm and Trương Bá Vương, Lý-789 (VNM!).

Aspidistra cadamensis
FIGURE 1. Aspidistra cadamensis N.S.Lý & Tillich. A. Plant in natural habit; B. Front view of flower; C. Side view of flower with peduncle; D. Basal part of the plant with flowers arising from the rhizome; E. Basal part with young fruit arising from the rhizome; F. Mature fruits arising from the rhizome. G. Portion of basal part and rhizome of plant showing flower and dried cataphyll; H. Flattened plant; I. Leaf blade, abaxial surface, base obtuse (I1), base cuneate (I2); J. Flower with peduncle and scales; K. Sterile bract; L. Longitudinal section of perigone showing stamens attached at basal third of tube; M. Longitudinal section of flower showing side view of pistil; N. Pistil
and stamens, side view (N1) and side view of pistil (N2); O. Basal half of the perigone with stamens; P1. Stigma, view from above, P2. Stigma, at aging stage, view from above; Q. Cross-section of fruit; R. Seeds. J–M, N–P, and Q–R share the same scale, respectively.

Phytotaxa 303 (1): 084–088

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