Holopogon (Chen, 1997)

Mu, Xian-Yun, Liu, Bing, Zhu, Yi-Xuan, Tong, Ling, Lin, Qin-Wen & Zhang, Zhi-Xiang, 2017, Holopogon pekinensis (Orchidaceae), a new heteromycotrophic species from Northern China, Phytotaxa 326 (2), pp. 151-155 : 154

Key to the species of Holopogon

1. Flowers actinomorphic, lip very similar to the petals; stigma antrorse (sect. Holopogon )................................................................2

1. Flowers zygomorphic, lip bilobed at the apex, utterly different from the petals; stigma slightly curved forwards (sect. Furcilla)..5

2. Sepals ovate-oblong or ovate, nearly twice as broad as petals, scarcely pubescent (northwest India) ................................................ ....................................................................................................................................... Holopogon microglottis (Duthie) S. C. Chen

2. Sepals oblong, as broad as petals.......................................................................................................................................................3

3. Flowers green, inflorescence and fruits with light green pubescence (Beijing City of China)............................................................ ....................................................................................................................................... Holopogon pekinensis X. Y. Mu & Bing Liu

3. Flowers purplish red or white, inflorescence and fruits with red pubescence....................................................................................4

4. Flowers white (Far East Russia)..................................................................................... Holopogon ussuriensis Komarov & Nevski

4. Flowers purplish red (Henan, Shanxi and Liaoning Province of China) ...... Holopogon gaudissartii (Handel-Mazzetti) S. C. Chen

5. Lip nearly oblong, slightly longer than or as long as the petals (endemic to Japan)... Holopogon japonicus (M. Furuse) S. C. Chen

5. Lip obovate or nearly cuneate, much longer than the petals..............................................................................................................6

6. Lip obovate, horizontally spreading; free filament 1/3-1/4 as long as the column (Sichuan and Shaanxi of China) .......................... .................................................................................................................................. Holopogon smithianus (Schlechter) S. C. Chen

6. Lip nearly cuneate, pointing upwards; free filament about 1/2 as long as the column (Sikkim) ......................................................... .................................................................................................................................... Holopogon pantlingii (W. W. Sm.) S. C. Chen