Paris tengchongensis Y.H. Ji, C.J.Yang & Y.L.Huang, 2017

Ji, Yunheng, Yang, Chengjin & Huang, Yuling, 2017, A new species of Paris sect. Axiparis (Melanthiaceae) from Yunnan, China, Phytotaxa 306 (3), pp. 234-236 : 234-236

Paris tengchongensis Y.H. Ji, C.J.Yang & Y.L.Huang sp. nov. ( Figs. 1 , 2 )

Paris tengchongensis can be distinguished from other species in Paris sect. Axiparis by sepals with purple markings, reddish purple petals, an ovoid ovary, and a sub-globose berry.

Type: — CHINA. Yunnan: Tengchong County, Houqiao Township, 3120 m, 25 º 34’02”N, 98 º 16’23”, 14 April 2015, Y. H. Ji 1341 (holotype KUN!, isotype KUN!, PE!).

Perennial herb, rhizome cylindrical, oblique or horizontal, 1–4 cm in diameter, 3–10 cm long, bearing a bud at the top and fleshy roots ca. 4–20 cm long. Stem erect, cylindric, 40–60 cm tall. Leaves 4–7 in a whorl at the top of stem, green; petiole green, ca. 1.5–4.5 cm long; blade oblong to elliptic, 7–12× 2–5 cm, base subcordate, apex acute; lateral veins one pair, basely developed, net veins obvious, 6–8 pairs. Peduncle yellowish green, 5–10 cm. Flower solitary, developing from top of stem. Sepals 4–7, ovate-lanceolate, 1.5–3cm × 5–10 mm, with purple markings at base or along midvein. Petals 4–7, narrowly linear, reddish purple, 3–6 cm × 2–3 mm. Stamens 2-whorled, filaments 4–8 mm, anther yellow, dehiscing by lateral slit, 5–10 mm long. Ovary 4- to 7-loculed, red, ovoid, placentation axile; stigmas 4–7, distinct, 5–15 mm long. Berry indehiscent, red, subglobose. Seeds ovoid, slightly enveloped by spongy aril.

Additional specimens examined (paratypes): — CHINA. Yunnan. Tengchong County: Houqiao Township , 3200 m, 25 º 33’57’’N, 98 º 16’58”, 16 August 16 2015, Y. H. Ji & C. J. Yang 021 ( KUN!) ; Gudong Township , 2810 m, 25 º 33’17”N, 98 º 16’08”, 18 August 2015, Y. H. Ji & C. J. Yang 029 ( KUN!); Jietou Township, 2950 m, 25 º 32’06”N, 98 º 15’44”, April 2016, Z. M. Wang s.n. ( KUN!) .

Distribution and ecology: —The new species is endemic to China, where it is only found on the west slope of Gaoligongshan Mountains in Tengchong County, Yunnan Province. The plant grows in bamboo thickets and conifer forests at 2750–3200 m a.s.l. It flowers in April, and its fruit reaches maturity in August.

Etymology: — The specific epithet “ tengchongensis ” is named after the type locality, Tengchong County, Yunnan Province, China.

Taxonomic relationships: — On the basis of its thick rhizome, ovary 4- to 7-loculed, axile placentation, fruit an indehiscent berry, and seeds enveloped by an imperfect aril, Paris tengchongensis is clearly a member of P. section Axiparis H.Li , a section so far represented by five species: P. axialis Li (1984: 273) , P. dulongensis H.Li & S.Kurita in Li (1992: 14), P. forrestii ( Takhtajan 1983: 268) Li (1984: 359) , P. rugosa H.Li & S.Kurita in Li (1992: 13), and P. vaniotii Léveillé (1906: 355) . Compared with other species in the section, P. tengchongensis shows closest affinity with P. forrestii . These two species share oblong to elliptic leaf blades that are subcordate at the base and acute at the apex, the petals longer than the sepals, and a red berry. However, P. tengchongensis is easily distinguished from P. forrestii in its sepals with purple markings (vs. markings lacking), reddish purple petals (vs. greenish yellow petals), and sub-globose berry (vs. angular berry). In addition, P. forrestii has been collected in evergreen broad-leaved forests at 1900–2500 m a.s.l. ( Li 1998), whereas P. tengchongensis occurs at of 2750–3200 m a.s.l. or higher, where bamboo thickets and conifer forests predominate.

Conservation status: — Paris tengchongensis is only known from three localities, and there are fewer than 1,000 mature individuals at each locality. The plant is commonly harvested as medicinal herbs by local people, which could result in continuing decline of population size and occupancy. According to the IUCN (2012) red list categories and criteria, P. tengchongensis should be assessed as Endangered, EN B2ab(iii, v). We assume that human activities in the region could lead them to rapid extinction.

Figures

FIGURE 1. Paris tengchongensis. A. flowering plant; B. sepal; C. petal; D. stamen; E. pistil; F. transverse section of ovary showing axile placentation; G. berry; H. transverse section of berry; I. seed enveloped by imperfect aril. Illustration drawn from the holotype by Dongyan Wang.

FIGURE 2. Paris tengchongensis. A. habitat; B. habit; C. rhizome and roots; D. leaves (abaxial and adaxial surface); E. sepals (abaxial and adaxial surface); F. pistil; G. transverse section of ovary showing axile placentation; H. berry; I. transverse section of berry; J. petals; K. stamens; L. seeds enveloped by imperfect aril.