Aspidistra quangngaiensis N.S.Lý, T.Haevermans & Tillich, 2017

Aspidistra quangngaiensis N.S.Lý, T.Haevermans & Tillich View in CoL sp. nov. ( Fig. 1 View FIGURE 1 )

Type:― VIETNAM. Quảng Ngãi Province, Nghĩa Hành District, Hành Tín Ðông Commune, Trường Lệ Village, Mount Dầu, Nhự hill , 14°51950′N, 108°48.467′E, 157 m elev., 23 September 2016, Ngọc-Sâm Lý & Thomas Haevermans Lý-807 (holotype VNM !; isotypes P! , VNM! ).

Perennial rhizomatous herb, 38.5–74 cm tall. Rhizome creeping, unbranched, epigeous, with dense short internodes, 5–8(–10) mm diam., brownish, with many swollen roots, up to 25 cm long, 4–6 mm in diam. Cataphylls 5–7, oblong to ovate-oblong, up to 14 cm long, the inner ones longer than the outer ones near the base, light greenish, whitish towards base, later straw-brown. Leaves solitary, ca. 0.5 cm apart, distinctly divided into petiole and lamina; petiole stiff, (14–) 22.5–45.5 cm long, green, ventrally with shallow v-shaped furrow, basally 5–7 mm swollen, whitish-green; lamina ovate, unequal, (19–)22–35 × (6.4–) 8.5–10.9 cm, tapering into attenuate tip, base somewhat rounded, adaxially dark-green, semi-glossy, abaxially light green, semi-glossy, mid vein strongly prominent on abaxial surface, each half of lamina with 3–4 prominent secondary veins, between them 4–9 fine-tertiary nerves with numerous anastomoses, somewhat prominent at lower surface, margin very minutely serrate. Flowers 1‒2, obliquely upright or horizontal, 22–40 mm long, 35–53 mm in diam., slightly fragrant. Pedicel stout, thick, obliquely upwards then horizontal, (1.2–) 2.5–3.9 cm long, 2.5–3.5 mm in diam., white with pale purple dots/spots, with 7–8 scale leaves, translucent white with densely purple dots at dorsal surface, with 9 translucent nerves, prominent on outer surface, apex acute or mucronate; basally 4–5 triangular ovate scales, 4.5–5.5 × 6– 5 mm, distally with 2–3 larger broadly ovate scales adjacent to flower, 14.3–16 × 11–14 mm. Perigone tube urceolate, fleshy, 14.5–18 mm long, 15–22 mm wide at base, mouth 6–8 mm wide, externally white at lower half, distally sparsely dark violet to black-violet, internally white at basal third, distally black-violet, finely verrucose at upper third, 6-lobed apically; lobes outcurved, ovate-lanceolate, acuminate, apex rounded, unequal, arranged distinctly in 2-whorls; lobes (13–) 18–27.5 mm long, 7–11.5 mm broad at base, each with two strongly prominent keels, 1–2.5 mm high, running from the lower third of adaxial side to the upper third of inner surface of perigone tube, dark violet to black-violet at basal half, distally white to greenish white, adaxially finely verrucose, abaxially smooth, thin marginal edges ca. 0.3 mm wide, deflexed; tube wall 1–1.5 mm thick, lobes 3–3.5 mm thick near base. Stamens 6, inserted at 2–4 mm from base of perigone tube (ca. 1/5 of the perigone tube), completely covered by stigma, arranged at the same radii with lobes; anther sessile, ovate, 3.3–4 mm long, ca. 1.5 mm wide near the base, yellow, latrorse, thecae separated by whitish connective tissue, without a connective appendage; pollen orange-yellow. Pistil table-shaped, 5–7 mm tall, ovary indistinct; style stout, shortly cylindrical, 2.5–3 mm long, 3–3.5 mm in diam., white; stigma fleshy, discoid-peltate, (14–) 18–22 mm in diam., filling nearly complete the base of tube, 3-lobed, upper surface flat, rough, densely purple-black mottled, verruculose, lower surface smooth, white at centre, deeply purple black with purple dots at margins, lobes with semicircular dents between them, leaving relatively large openings for pollination, each lobe emarginated and reflexed. Fruits not seen.

Distribution and Ecology:―This species is currently known only from type locality, where several subpopulations of scattered mature clumps of non-flowering and flowering are rather frequent around Mount Dầu. For this reason, we believe that this new species can be considered as locally abundant and treated as an endemic species. It grows on hill slopes composed of eroded sandstone at 130–270 m elev., under the canopy or shady areas of secondary evergreen broad-leaved forest dominated by Dipterocapus Gaertner (1805: 50) sp. pl., Parashorea Kurz (1870: 65) sp. pl. ( Dipterocarpaceae ), Dialium cochinchinense Pierre (1899: t. 384 A), Peltophorum pterocarpum Backer ex Heyne (1927: 755) , Afzelia xylocarpa Craib (1912: 267) ( Fabaceae ), Scaphium macropodum Beumee ex Heyne (1927: 1068) ( Malvaceae ), and ground herbs dominated by some recently described species of gingers (Zingiberace) from Mount Dầu as Alpinia newmanii Lý (2017: 177) , Newmanina serpens Lý & Škornič. (2011: 1390) , N. orthostachys Lý & Škornič. (2011: 1392) , Zingiber skornickovae Lý (2016: 140) .

Conservation status: ―Vulnerable VU B1ab(iii). Small subpopulations of Aspidistra quangngaiensis occur on Mount Dầu with a total area of occupancy of 6.5 km 2 (650 ha). Although this species is under the protection of the local authorities of Khánh Giang and Trường Lệ Villages (Quảng Ngãi Province), these populations are, however, vulnerable and continuing to decline in area, extent and quality of habitat due to destruction through human activities, such as harvesting of non-timber forest products, forest fires, and especially clearing of forest land for Acacia Miller (1754: 25) plantations. According to the IUCN Red list criteria ( IUCN, 2012), we propose to rate this taxon as vulnerable VU B1ab(iii).

Etymology:―The specific epithet is named after the geographical locality where the new species was discovered.

Additional specimens examined (paratypes):― VIETNAM. Quảng Ngãi Province, Nghĩa Hành District, Hành Tín Ðông Commune, Trường Lệ Village, Mount Dầu, Nhự hill , 14°51.365′N, 108°49.512′E, 225 m elev., 23 September 2016, Ngọc-Sâm L ý & Thomas Haevermans Lý-808 ( VNM!) GoogleMaps ; ibidem, 14°51.991′N, 108°48.762′E, 270 m elev., 23 September 2016, Ngọc-Sâm Lý & Thomas Haevermans Lý-809 ( VNM!) GoogleMaps .

Taxonomic relationships:― Aspidistra quangngaiensis is similar to A. phanluongii Vislobokov (2013: 349) from Đồng Nai Reserve, Đồng Nai Province (ca. 440 km S from Mount Dầu) in having the low, table shaped pistil, violet colour, urceolate tube, and lobes with two keels, but differs in the ovate leaves (vs. lanceolate to elliptic), larger flowers, 14.5–18 × 15–22 mm (vs. smaller, 10.5–16.5 × 10–16 mm), and much larger, ovate-lanceolate and recurved lobes, (13–)18–27.5 × 7–11.5 mm (vs. smaller, oblong and reflexed, 5–7.5 × 3–4.5 mm), filament missing (vs. 0.5–0.8 mm), and larger flat stigma, (14–) 18–22 mm in diam. (vs. smaller, 10–13 mm). Aspidistra quangngaiensis is slightly similar to A. ventricosa Tillich & Leong-Škorničková (2014: 28) , from Núi Chúa National Park, Ninh Thuận Province (ca. 350 km SE from Mount Dầu) by the same plant habit, perigone and pistil shape. The purple flowers, much smaller, triangular, reflexed lobes with three keels, short filament and smaller stigma of A. ventricosa distinguishes it from the new species.