Cheniella tsoongii (Leguminosae: Cercidoideae), a rare, critically endangered new species from southern China Author Peng, Xia 0009-0004-1347-4464 State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China & University of Chinese Academy of Sciences, Beijing 100049, China pengxia@scbg.ac.cn Author Jiang, Kai-Wen 0000-0002-5917-1846 State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China & University of Chinese Academy of Sciences, Beijing 100049, China & Ningbo Botanical Garden, Ningbo 315201, China kevinchiangensis@gmail.com Author Fang, Tian-Song 0009-0003-9835-0622 Guangdong Forest Resources Conservation Center, Guangzhou 510173, China fts1973@126.com Author Gu, Qiao-Yun 0009-0006-4676-6433 Guangdong Forest Resources Conservation Center, Guangzhou 510173, China 57616162@qq.com Author Gu, Shi-Ran State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Xie, Zhi State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Duan, Lei State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Li, Shi-Jin State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Wang, Xiang-Ping State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Shi, Miao-Miao State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Tu, Tie-Yao State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China Author Zhang, Dian-Xiang State Key Laboratory of Plant Diversity and Specialty Crops / Guangdong Provincial Key Laboratory of Applied Botany / Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China & South China National Botanical Garden, Guangzhou 510650, China text Phytotaxa 2024 2024-05-02 646 2 193 202 http://dx.doi.org/10.11646/phytotaxa.646.2.8 journal article 302197 10.11646/phytotaxa.646.2.8 3cbf0891-91d6-444e-8036-4661c84fb1a2 1179-3163 13215377 Key to species of Cheniella 1. Leaf entire to emarginate, bilobed to less than 1/5 of length .............................................................................................................2 - Leaf bilobed to at least 1/4 of length ..................................................................................................................................................5 2. Leaf entire, ovate, hairy on lower surface ....................................................................................................................... C. ovatifolia - Leaf emarginate, hairy on lower or both surfaces ..............................................................................................................................3 3. Leaf densely tomentose; ovary villose along both sutures; legume hairs ferruginous................................................. C. tianlinensis - Leaf pubescent; ovary glabrous or with few hairs; mature legume glabrous.....................................................................................4 4. Leaf on lower surface dark ferruginous tomentose, white tomentose on upper surface; inflorescence a raceme, ferruginous tomentose; pedicel persistent after flowering, hypanthium 23–25 mm ; ovary glabrous ......................................... C. clemensiorum - Leaf on lower surface pale ferruginous appressed hairy, tomentose, villose, or pilose on veins, upper surface glabrous; inflorescence a raceme or corymb, pale tomentose; pedicel falling after flowering, hypanthium 7–20 mm ; ovary with few hairs at the base........ ................................................................................................................................................................................... C. quinnanensis 5. Leaf length ≤ 51 mm , bilobed to ≥ 1/2 of length................................................................................................................................6 - Leaf length 20–80 mm , bilobed to ≤ 1/2 of length...........................................................................................................................10 6. Petals yellowish green; hypanthium 4–8 mm ; ovary mostly glabrous but with ferruginous hairs along the dorsal suture................. ........................................................................................................................................................................................ C. hechiensis - Petals white or pink; hypanthium 9–28 mm ; ovary glabrous.............................................................................................................7 7. Leaf bilobed almost to the base, or the lobes joined by ca 1–2 mm ; petals white; hypanthium 9–15 mm ......................... C. didyma - Leaf bilobed to a lesser degree, the lobes joined by at least 3 mm ; petals white or pink; hypanthium 11–28 mm ...........................8 8. Inflorescence an elongate raceme, axis length 2–16 mm ; petals white, flowers zygomorphic; lengths of fully developed stamens and mature pistils 10–22 mm ; legume curved or twisted, tardily dehiscent along one or both sutures............................ C. longipes - Inflorescence a corymb, axis length 2–7 mm ; petals white or pink, flowers nearly actinomorphic; lengths of fully developed stamens and mature pistils 10–15 mm ; legume straight, tardily dehiscent ........................................................................................9 9. Petals pink; hypanthium length 18–28 mm ; upper surface of leaves and branches glabrous, lower surface of leaves sparsely appressed pilose............................................................................................................................................................. C. corymbosa - Petals white; hypanthium length 11–16 mm ; both surfaces of leaves and branches densely hairy ...................... C. tsoongii sp. nov. 10. Leaf width greater than length; legume hairy................................................................................................................. C. pubicarpa - Leaf length greater or lesser than width; legume glabrous...............................................................................................................11 11. Hypanthium length ≤ 14 mm ............................................................................................................................................................12 - Hypanthium length ≥ 15 mm ............................................................................................................................................................14 12. Hypanthium distinctly inflated at the base; petals yellowish to greenish; ovary hairy along lower suture ................. C. touranensis - Hypanthium not distinctly inflated at the base; petals white; ovary glabrous..................................................................................13 13. Inflorescence a corymb; hypanthium glabrous, or with very few hairs at base, 10–15 mm long; petals white, width ≥ 5 mm .......... .............................................................................................................................................................................................. C. glauca - Inflorescence a raceme, or lax and few-flowered; hypanthium sparsely to moderately pilose, slender, 5.5–8.5 mm long; petals yellowish white, width ≤ 4mm ............................................................................................................................ C. damiaoshanensis 14. Buds with sepals folded to form 5 prominent longitudinal ridges, deflexed from pedicel; flowers zygomorphic; petals white; fertile stamens at least two times longer than the petals; legume straight or slightly curved, tardily dehiscent ................ C. longistaminea - Buds psilate, without ridges, not deflexed from pedicel; flowers nearly actinomorphic; petals white, pinkish or pink; fertile stamens nearly equal in length to petals; legume straight, indehiscent..........................................................................................................15 15. Inflorescence axillary; petals white with pink stripes; legume width 17–23 mm ....................................................... C. lakhonensis - Inflorescence terminal; petals white to pink; legume width 30–60 mm ......................................................................... C. tenuiflora