Dichocarpum wuchuanense S. Z. He, 2015

Jiang, Wei-Ke, Ding, Ling, Zhou, Tao, He, Shun-Zhi, Li, Yun-Chao & Huang, Lu-Qi, 2015, A new species of Dichocarpum (Ranunculaceae) from Guizhou, China, Phytotaxa 227 (1), pp. 66-74 : 71-73

Dichocarpum wuchuanense S. Z. He , sp. nov. ( Fig. 7 )

Dichocarpum wuchuanense resembles D. hypoglaucum W. T. Wang & P. K. Hsiao , but differs from it by its slender and longer rhizome, 3(‒5)-foliolate abaxially non-pruinose and smaller seeds.

Type:— CHINA. Guizhou: Wuchuan, Yangxi, Woyang Valley , on limestone in a bushy ravine, elev. 650 m, 28°31′14.32″‒ 28°31′14.37″N, 107°52′22.50″‒ 107°52′22.51″E, 20 April 2008, Y. C. Li 080420 (holotype: GZTM!; isotype: GZTM!) .

Perennial herb, glabrous. Rhizome robust, 2‒8 cm, ca. 0.4‒1 cm in diameter. Unbranched or few branches, with numerous fibrous roots. Leaves 2‒3, basal, pedately compound, 3(‒5)-foliolate, papery, petiole 20‒25 cm, leaf blade 6‒14 × 3‒6.5 cm, central leaflet rhombic-ovate, base cuneate or ovate, above mid-lower margin with 3‒8 pairs shallow coarse teeth, apex attenuate, leaflet petiole 1.6‒5 cm; lateral leaflets 1‒2, oblique ovate, 5‒12 × 3‒5 cm. Flowering stem ca. 18‒38 cm tall. Inflorescence monochasium or dichasium, 2‒11 flowered; bract obovate, 3-lobed, lower bracts 0.6‒1.8 cm, shortly petiolate, upper bracts not split and smaller; pedicel 2‒4cm. Sepals 5, ovate-oblong, white, 0.6‒1.4 × 0.4‒0.7 cm, apex acute. Petal limbs rounded or fan-shaped, golden yellow, apex curved, 1.5 × 2 mm, claw 2‒3 mm. Stamens 15‒20, anther narrowly oblong, ca. 1.2 mm. Filaments ca. 6.5 mm; ovary narrowly obovate, 0.7‒1.2 cm, persistent styles ca. 2 mm. Follicles lanceolate, 9.5‒ 1.5 cm, beaks 2.5‒3 mm. Seeds ovate, brown, ca. 1 mm, hilum subround, raphe distinctively raised. Flowering April‒May, fruiting May‒June.

Distribution, habitat, and ecology:— The new species is only known from a ravine, northeast of Wuchuan in Guizhou, China ( Fig. 8 ), elev. 650‒1000 m, where two populations of more than 100 individuals were found. Annual rainfall in this region varies ca. 1280 mm and occurs mainly in the summer, with a mean annual temperature of 15.6 °C and an annual frost-free period of 287 d, as a subtropical humid monsoon climate.

Phenology:— Flowering April‒May, fruiting May‒June.

Etymology:— The specific epithet is derived from the type locality, Wuchuan in the northern part of Guizhou, China.

Additional collection:— CHINA. Guizhou: Wuchuan, Yangxi, Woyang Valley, elev. 650 m, 9 April 2014, LING DING 2014040902 (GZTM), Wuchuan, Yangxi, Woyang Valley, elev. 947 m, 9 April 2014, LING DING 2014040908 (GZTM).

Figures

FIGURE 7. Dichocarpum wuchuanense S. Z. He. a flowering and fruiting states; b ovary; c fruit; d petal; e sepal; f stamen; g seed. Drawn by Xiang-li Wu from the holotype.

FIGURE 8. Distribution map of Dichocarpum wuchuanense in China.