Anoectochilus medogensis H.Z. Tian & Y. Jin, 2021

Jin, Yue, Sun, Mei, Jiang, Hong, Kumar, Pankaj, Liu, Zhen, Schuiteman, Andre, Wu, Jianyong & Tian, Huaizhen, 2021, Anoectochilus medogensis (Goodyerinae, Cranichideae, Orchidaceae), a new species from Tibet, China, Phytotaxa 510 (3), pp. 213-227 : 216-219

Anoectochilus medogensis H.Z. Tian & Y. Jin sp. nov. FIGURE 2–3

Type:— CHINA. Tibet: Motuo , 1,700 m, 17 August 2019, Tian et al. 20190817003 (Holotype HSNU0079764 ). Paratypes : Tibet: Beibeng, 1,700 m, 17 August 2019, Tian et al. 20190817004 ( CSH0180101 ); 1,600 m, 18 August 2019, Tian et al. 20190818006 ( PE); 20190818017 ( HSNU0079765 ); 1,530 m, 5 August 2018, H. Jiang et W. P. Zhang 07465 ( YAF 07465) .

Diagnosis:— Anoectochilus medogensis is similar to A. albolineatus but can be differentiated on the basis of broad, semi-circular column wings (vs. narrow, straight column wings). It also shows a close morphological affinity to A. elatus , however, the spur of A. medogensis is ca. 4.5 mm, much shorter than that of A. elatus (over 8 mm long).

Description:—Terrestrial herbs, plant 15–22 cm tall, stem ascending, 3–5-leaved. Leaves adaxially almost black with fine white to golden veins, abaxially tawny, ovate to orbicular, apiculate, apex acute, 3–6 × 3–4 cm; petiolelike base and tubular sheath, 1–1.5 cm long. Inflorescence pubescent, 15 cm long, 3–12-flowered, with 2 brown, ovate-lanceolate, caudate, abaxially pubescent, up to 1 cm long peduncle–scales; floral bracts similar to the pedunclescales, 0.6 cm long. Flowers resupinate, reddish-brown to green, ovary and pedicel twisted, fusiform, 1.5 cm; sepals concave, green with reddish-brown apex, pubescent on the outer surface; dorsal sepal 7 × 4.5 mm, ovate-orbicular, apex apiculate; lateral sepals obliquely elliptic, apex cuspidate, 12 × 4 mm; petals obliquely falcate, greenish-white, apex long acuminate, middle part widest, 2.5 × 5 mm, joined with dorsal sepals to form a hood; lip white, Y-shaped, 15 mm long, epichile ca. 5 mm long, longitudinally dilated, 2-lobed, lobes diverging at an acute angle, entire; mesochile 5 mm long, flange bearing 7 or 8, 8– 12 mm long hair-like filaments on each side, basal half near hypochile green; spur conical, 4.5 mm long, apex shallowly bilobed, parallel with ovary, containing 2 trapezoid calli. Column ca. 5 mm long, stout, ventrally with 2 broad, semicircular lamellae, not projecting into the spur. Stigma lobes 2, distinct, located to the sides of the rostellum. Anther cap ovate, brownish-yellow, 3–4 mm. Pollinia 2, shortly caudiculate, obliquely clavate, yellow, 3.5 mm long. Fl. Jul.–Aug.

Vernacular name:—“mo tuo jin xian lan” “Ḇüżȗ兰”.

Etymology:—The specific epithet refers to the name of the type locality, Medog County. Medog County is the English name of Motuo, belonging to Nyingchi Prefecture, in the Tibet Autonomous Region.

Ecology:— Anoectochilus medogensis grows as a terrestrial herb in dense and humid broad-leaved forests at an elevation of 1,500 –1,700 m. ( FIGURE 2 )

Distribution:— CHINA: Tibet, endemic.

Conservation status:—During the survey in Motuo, the new species was only found at two separate sites, each containing a small sub-population comprising not more than 100 mature individuals. Plants are known to be collected for use in Traditional Chinese Medicine, which is a major threat to this species of the restricted distribution and a small population size. Considering that valuable ingredients in Anoectochilus have been identified ( Cui et al. 2013, Yin et al. 2016, Li et al. 2018, Mei et al. 2018), the risk of collection remains high. Hence, there is an evidence of continuing decline in the number of mature individuals. Area of Occurrence was calculated using GeoCAT ( Moat 2007) as 8 km 2. Fruit set was not observed. On the basis of available information on population size of less than 200 mature individuals and continuing decline in number of mature individuals, the species can be assessed according to IUCN guidelines ( IUCN 2020) as Critically Endangered [CR: B2ab(v)].

Figures

FIGURE 2. Anoectochilus medogensis (from the holotype 20190817003) A, habit; B, sepals and petals; C, anther cap and pollinia; D, leaves; E, side and top view of flower without petals and sepals; F, column and spur (side view, with pollen on stigmas); G, column and calli in spur (front view, with pollen on stigmas).

FIGURE 3. Anoectochilus medogensis A, plant; B, sepals and petals; C, flower (front view); D, flower (side view); E, column and calli in spur (lateral view); F, column and calli in spur (front view); G, pollinia.