Paris nitida G.W.Hu, Z.Wang & Q.F.Wang, 2017

Paris nitida G.W.Hu, Z.Wang & Q.F.Wang View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 )

The new species differs from Paris caobangensis Ji et al. (2006: 700) by its smaller individuals, stem only 10–15 cm tall; leaf blades elliptic, thick membranous to subcoriaceous, lustrous adaxially; petioles only 3–8 mm long; sepals elliptic; petals 1.2–1.8 cm long, shorter than half length of sepals; stamen 4–10, in 1–2 whorls, filaments only 3–5 mm long, free portion of connective 1–2 mm long, rounded at apex; stigmas revolute.

Type: — CHINA. Hubei Province: Tongshan County, Jiugongshan Mountain, Anping , under forest, 29° 23′ N, 114° 35′ E, elev. 1070 m, 7 April, 2016, G. W. Hu & Z. Xu HGW-01060 (holotype, HIB! GoogleMaps ; isotypes, HIB! GoogleMaps , HNNU! GoogleMaps ).

Perennial herb, erect, glabrous. Rhizome thickened to cylindrical, oblique or horizontal, yellowish-brown outside, white and starchy inside, 3–3.5 cm long, 0.8–1.2 cm in diameter, fibrous roots borne only on the three newborn nodes. Stem simple, cylindric, green or purplish-red, 10–15 cm tall, 3–5 mm thick, surrounded by three white membranous scales at base, the scales left three inconspicuous rings of scars on the rhizome when they withered. Leaves 4–5 in a whorl at the top of stem; petioles 3–8(–13) mm long; leaf blades elliptic, 5.5–7.5 × 1.9–2.5 cm, green, lustrous, thick membranous to subcoriaceous, apex acuminate, base cuneate or subrounded; triplinerved, middle vein obvious, net veins inconspicuous. Flower solitary and terminal; pedicel 2–6 cm long, often purplish red; sepals (3–)4–5, usually with same number as leaves, seldom 1 less than them, green and lustrous adaxially, pale green abaxially, elliptic, 3.5–4.2 × 1–1.4 cm, base cuneate or rounded, with a very short claw, apex acuminate, persistent; petals (3–)4–5, filiform, 1.2–1.8 cm long, shorter than half length of sepals, persistent, usually pendent under sepals, light green at lower 3/4 portion, green-yellow at upper 1/3 portion; stamens 4–10, in 1–2 whorls, filaments yellow-green, 3–5 mm long, anthers golden yellow, 6-8 mm long, free portion of connective 1–2 mm long, rounded at apex; ovary ovoid, yellow-green at base, purplish red on the top, with (3–)4(–5) longitudinal ridges, carpels (3–)4, unilocular with parietal placenta, anatropous ovules ovate, white, transparent, numerous, on two longitudinal rows along every placenta; style ca. 1 mm long, style base purple, disciform; stigmas (3–)4, free, ca. 1.5 mm long, purple, revolute. Capsule spheroidal, with (3–)4(–5) longitudinal ridges, green at maturity, 0.8–1.4 cm in diameter, irregularly dehisces between ridges. Seeds numerous, ovoid, white, wholly enveloped by red, fleshy and juicy aril.

Distribution: —The new species is known from Jiugongshan Mountain and Taiyangshan Forest, Tongshan County, eastern Hubei Province and Daweishan Mountain, Liuyang County, eastern Hunan Province at elevations of 730–1420 m. Our field investigations in western Hunan (Hongjiang County) and western Hubei (Changyang County) found some more individuals of this species cultivated by local farmers, who stated that these plants were collected from the mountains around, but exact localities were unknown. It is possible that Paris nitida has a relatively wide distribution in South Central China and more studies are needed.

Ecology & Habitat: — Paris nitida grows under forest at elevations of 730–1420 m. The vegetation in the areas is subtropical evergreen forest.

Phenology: —The new species was observed in flower from March to May and in fruit from September to October.

Etymology: —The epithetic “nitida ” refers to the shiny character of adaxial leaf surface of the new species.

IUCN Red List Category: —Three populations of Paris nitida were found from Jiugongshan Mountain, Taiyangshan Forest, Daweishan Mountain in Hubei and Hunan Province, China. The species is considered ‘Endangered’ (EN B2ab(v)) using the criteria set out by IUCN (2012) and China species red list ( Wang & Xie 2004) as it has been collected from only 3 sites, its known area of occupancy is less than 100 km 2 and the number of mature individuals is in extreme fluctuation. However, due to its recent discovery, the full range of its distribution is unknown and further evaluation is needed.

Additional specimens examined (paratypes): — CHINA. Hubei Province: Tongshan County, Xiapu Township, Taiyangshan Forest , elev. 730 m, 16 October 2014, H.D. Huang & D.C. Bao 001007 ( HIB!) ; 29° 20′ N, 114° 30′ E, elev. 930 m, 8 April 2016, G.W. Hu & Z.Xu HGW-01061 ( HIB!) GoogleMaps . Hunan Province, Liuyang County, Daweishan Mountain: Yuquan Lake , 28° 25′ N, 114° 06′ E, elev. 1420 m, 14 April 2016, Z. Wang wz-0659 ( HIB!; HNNU!) GoogleMaps ; On the way from Yuquan Lake to Chuanwodi , 28° 25′ N, 114° 06′ E, elev. 1330 m, 14 April 2016, Z. Wang wz-0661 ( HIB!; HNNU!) GoogleMaps ; Chuanwodi, 28° 25′ N, 114° 06′ E, elev. 1280 m, 14 April 2016, Z. Wang wz-0662 ( HIB!; HNNU!) GoogleMaps ; Chuanwodi , 28° 25′ N, 114° 06′ E, elev. 1230 m, 27 October 2016, Z. Wang wz-0699 ( HIB!; HNNU!) GoogleMaps .

Taxonomic relationships: —Morphologically, the new species Paris nitida is similar to P. caobangensis in characters such as the number of tepals equal to the leaves, triplinerved leaf blade, green calyxes, and seeds wholly enveloped by red, fleshy and juicy aril. Differences of the new species from P. caobangensis include individuals much smaller, stem only 10– 15 cm tall, leaf blades elliptic, thick membranous to subcoriaceous, lustrous; petioles only 3–8 mm long (vs. stem 30–35 cm tall, leaf blades ovate-lanceolate, papery, petiole 2.5–3 cm long in P. caobangensis ); sepals elliptic (vs. ovate-lanceolate in P. caobangensis ); petals 1.2–1.8 cm long, shorter than half of sepals (vs. 6–9 cm long, longer than sepals in P. caobangensis ); filaments only 3–5 mm long, stigmas revolute (vs. filaments 1.6–1.9 cm long, stigmas erect in P. caobangensis ).

Palynology: —Pollen grains of Paris nitida are prolate in polar view, moncolpate, regulate-reticulate, 40.8–42.5 × 18.3–20.8 (P [polar length] × E [equatorial length]) μm ( Fig. 2 View FIGURE 2 ).