Apios chendezhaoana (Y.K. Yang, L.H. Liu & J.K. Wu) Bo Pan

Zhang, Fan, Feng, Si, Zhou, Jianjun, Zhang, Rong, Liu, Linhan, Yang, Chengzi, Yu, Xunlin & Pan, Bo, 2018, Apios chendezhaoana (Fabaceae), an overlooked species and a new combination from China: evidence from morphological and molecular analyses, Phytotaxa 371 (1), pp. 1-16 : 4-6

Apios chendezhaoana (Y.K. Yang, L.H. Liu & J.K. Wu) Bo Pan (Ñṻ), Xun-Lin Yu, & Fan Zhang, comb. nov. (Figure

2 & 3) (ḿṅŀ Į)

Basionym :— Sinolegumenea chendezhaoana Yong-Kang Yang, Lin-Han Liu & Jia-Kun Wu, (2004: 62–76) . syn. nov.

Type: — CHINA. Hunan: Yanling, Pikeng Forestry Station, hillside, 600 m, sandy soil, among roadside grasses, rare, ca. 1.5 m long, 30 July 1973, Barcode 18447, labelled ‘ Dunbaria hunanica sp. nov. ined. ’, Lin-Han Liu 11227 (holotype HNNU!).

Perennial, herbaceous, twining climber, 1.5–3 m long, above-ground part deciduous in winter. Broken parts produce white latex. Root usually with 2–4 tubers, 3–7 cm long, connected by long stalks. Tubers fusiform, 3–7 cm long, 5–10 mm in diameter, sometimes segmented. Rootstalk 4–12 cm long, erect, connected to the top of tubers. Adventitious roots usually clustered at the end of lower tubers, ca. 30 cm long, horizontally stretched in the top soil on the surface of granite rocks. Soil layer on the rock is about 20 cm deep, soft, dark brown in color and humid. Stem slender, dark reddish brown, tomentose. Leaves 3–5 pinnately foliolate, sometimes only one foliolate. Stipules filiform, ca. 4 mm, hirsute, caduceus. Petiole green or dark reddish brown, ca. 3–9 cm, tomentose. Petiolules small, densely hirsute. Stipels small, 1–2 mm, awn-shaped. Leaflets membranous, all 10 mm caudate, tips mucronate, glabrous on both sides, or with sparse horizontal hairs along main veins. Upper side green, lower side glaucous. Terminal leaflet broad triangular or triangular-ovate, membranous, 3.5–10 × 3.5–10 cm; apex acute, base truncate and wide. Lateral leaflets smaller, rhomboid ovate, oblique, 2.5–9 × 1.5–6 cm. Inflorescence 6–22 flowered, a nodose pseudoraceme, solitary and axillary, sometimes 2–3 clustered from one axil, 2–8 (–13) cm, usually 2 flowers per node; peduncle 1–2 cm; rachis somewhat zigzag; nodes swollen; sometimes the lowest node subtended with 1-foliolate leaf; bracts linear, 1–3 mm, minute; bracteoles subtending the calyx, 1.5 mm; pedicels ca. 7 mm. Calyx campanulate, 5–7 mm, 4 toothed, the upper lobe the widest, and the lower tooth the longest, appressed hairy on the outer surface; inner surface of calyx sparsely hairy on the teeth and the upper area along the calyx tube, while glabrous on the lower part. Corolla white, exerted, longer than the calyx, ca. 15–17 mm. Flowers usually incompletely open, with standard apex and keel apex very close to each other. Standard the largest, covering up all the other petals, ca. 12–17 × 11–16 mm, like a pocket in shape, not revolute, with a green patch at the lower part, shortly auriculate at both sides, shortly clawed 2.5 mm; wings much smaller, 8 × 3 mm, oblong, refolded into a S shape, auriculate on one side, ca. 2 mm clawed; keel ca. 14 × 5 mm, falcate and very curved, the lower 2/3 connate, and the upper 1/3 separate; keel claw 3 mm; lower part of blades with pink markings. Stamens diadelphous, 9+1, 10–13 mm; anthers ovoid, equal in size. Pistil filiform, 10–12 ovuled, ca. 13 mm, shortly hairy; style coiled and dilated; stigma capitate, with several short tufts of hairs beneath. Floral disc at the base of the pistil, yellowish green, 1.5 mm. Pods linear to falcate, glabrous, 9–13 cm long, 7–11 mm wide, attenuate towards base, ca. 10 seeded; valves leathery, twisted when dry; seeds orbicular, laterally compressed, 7–10 mm, black and nitid; aril short, 0.5–1 mm; hilum linear, 0.5–0.7 mm, slightly sunken, white in color,

Phenology: —Flowering June to August, fruiting August to October.

Distribution and habitat: ( Figure 4 )— A. chendezhaoana , endemic to China, occurs only in moist and shady gullies of the Luoxiao, Nanling, and Wuyi Mountains along the borders of Fujian, Guangdong, Hunan, and Jiangxi provinces, at elevations between 400–1300 m. It climbs in bushes of the evergreen broadleaved forest undergrowth. The soil is usually wet, shallow and soft, dark brown in color.

Etymology: —The Latin epithet is in honor of a female botanist, Mrs. Te-Chao CHEN (ḴDZffi, Chen Dezhao in Chinese pinyin), from the South China Botanical Garden, who contributed to the treatments of many legumes in the Flora of China. The Chinese name ‘ ḿṅ ’ refers to one of its main areas of distribution in China —the Nanling Mountain Range.

Conservation status:— Apios priceana was listed as an endangered species in the USA because there are only 47 known populations from 22 counties in four states ( Woods 2005). The situation of A. chendezhaoana is very similar to this. We have so far found only 23 specimens and 15 recorded populations from four provinces. Each population has only 1–10 known individuals, and each location is very remote from the next. The total number of individuals is estimated to be less than 250, allowing for undiscovered populations. Most specimens were collected decades ago and recent records are rare. Like all its allies, but unlike most legumes, this species prefers shady and undisturbed habitats, shallow and fertile soils, along creeks and streams, so it is very susceptible to human disturbance. In view of the very small number of individuals and scattered distribution, we evaluate this species as Endangered (EN D) in accordance with the IUCN Red List Categories and Criteria version 3.1 (2001) (http://www.iucnredlist.org/static/ categories_criteria_3_1).

Additional specimens examined:— CHINA. Fujian: Taining, Datian, Yangkeng, among grasses in forest, 10 July 1979, labelled ‘ Apios fortunei ’, Ming-Sheng Li 971 (IBSC). Guangdong: Longtou Shan, Lingnan, in small ravine, along hillside. Vine 1.8 m. Flower white. 15 July 1924, labelled ‘ Apios fortunei ’, To & Tsang 12895 (NAS, P). Beijiang, Yaoshan, Huangdong, 686 m, 19 June 1930, labelled ‘ Apios fortunei ’, Shu-Chi Xin 10027 (IBSC). Qujiang, Xiaokeng Forestry Station, sparse forest, streamside, rare, 6 August 1985, Nanling Team 850 (IBSC). Lechang, Liangjiang, Shizishan, 700 m, in valley, sparse forest, 28 October 1987, Lechang Team 4100 (IBSC). Shixing, Duheng, Taoyuan, 580 m, 17 July 1982, Gui-Cai Zhang & Hua-Gu Ye 447 (IBSC). Heping, Liyuan, Qutan, 500 m, 5 August 1983, Gui-Cai Zhang & Hua-Gu Ye 365 (IBSC). Hunan: Yanling, Pikeng Forestry Station, 38KM, hillside, 450 m, humid soil, in valley, along roadside within a 25 m distance, sparse forest, canopy cover 15%, scattered, 30 August 1985, Lin-Han Liu 11439 (HNNU). Yanling, Taoyuandong, Niujiaolong, Qiguxian, Shunfengqiao, 1270 m, in valley, fertile loam, streamside, under dense broadleaved forest, canopy cover 70%, rare and scattered, 14 September 2008, Lin-Han Liu & Ying-Di Liu 30105 (HNNU). Jianghua, Daxi, Jilong village, hillside, 500 m, in valley, dense forest, roadside, rare, 18 July 1999, Guang-Wan Hu 219082 (HNNU). Jianghua, Daxi, hillside, 240 m, in valley, sparse forest, rare, 9 September 1999, Ke-Ming Liu 767215 (HNNU). Yizhang, Qitianling Forestry Station, streamside, under broadleaved forest, 1078 m, 2 August 2017, Xun-Lin Yu & Fan Zhang 1708020101 (CSFI). Jiangxi: Zixi, Matoushan (Wuyi Mountain), in bamboo shade, streamside, 450 m, 15 July 1958, Min-Xiang Nie & Shu-Shen Lai 3455 (LBG, KUN). Jinggangshan, Ganggangshan, roadside along shady slope, grassland, 1300 m, 9 July 1965, Shu-Shen Lai, Ru- Jü Yang & Da-Fu Huang 4393 (KUN, LBG). Anfu, Wugongshan, Wenjiadaling, in forest undergrowth, shady slope, along the creek, 800 m, 8 August 1963, Jun-San Yue 3172 (KUN, NAS). Anfu, Wugongshan, Dabeitou, in streamside bushes, 500 m, 3 August 1963, Jun-San Yue 2773 (KUN, NAS). No. 007955, Jinggangshan, June 1975, labelled ‘ Apios fortunei ’, Anonymous 75002 (JXCM). No. 007358, August 1971, Anonymous s.n. (JXCM). No. 741143, labelled ‘ Vigna umbellata ’, Anonymous s.n. (JXU).

Figures

FIGURE 4. Geographical distribution of Apios chendezhaoana. Prepared by Dr. Rui-Wu Zhou.