ABSTRACT. Two sections in the genus Pleione D. Don are recognized here. The acceptance of Pleione praecox as the lectotype of the generic name Pleione (J. E. Smith) D. Don makes Pleione sect. Dictyopleione synonymous with Pleione sect. Pleione. A new name, Pleione sect. Humiles G. Zhu & S. C. Chen, is proposed for the other section represented by P. humilis (J. E. Smith) D. Don, which is described here. A key to sections and a list of currently recognized species of the genus are provided.

Pleione D. Don (Orchidaceae, Coelogyneae) is a small genus of great beauty. Nineteen species are currently recognized, occurring from the Qinling Mountains in central China, southeast to Taiwan, southwest to the Himalayas, and south to northern Thailand, Laos, and Vietnam in subtropical Asia. They grow in a wide variety of usually well drained habitats, on tree trunks, woody slopes, and on rocks and cliffs covered with mosses, occurring at altitudes from 600 to 4200 m. The plants are of great horticultural importance, because they all have one showy flower and are easy to cultivate and propagate by vegetative means. There have been many artificial hybrids reported in recent years. There are also modern revisions of this economically important genus (Cribb et al., 1983; Cribb & Butterfield, 1988). The present paper deals with an unresolved nomenclatural problem of the sections in the genus.

Pleione was established by David Don (1825) based on two Himalayan species previously described by James E. Smith, namely Epidendrum praecox and E. humile. However, there was no indication of a type species. Half a century later, Ludovicus Pfeiffer (1874) cited the species Epidendrum praecox J. E. Smith after the generic name Pleione. According to his introductory comments at the start of the work, Pfeiffer used this method to indicate types, and the species Pleione praecox (J. E. Smith) D. Don is here accepted as the lectotype of the generic name Pleione. Subsequently, in Engler’s Das Pflanzenreich, Ernst Pfitzer recognized 13 species of Pleione, which he placed in two sections: section Eupleione with 8 species and section Dictyopleione with 5 (Pfitzer & Kraenzlin, 1907). Unaware of Pfeiffer’s earlier typification, Pfitzer placed P. praecox in his section Dictyopleione, and P. humilis (J. E. Smith) D. Don in section Eupleione. No type was designated for either sectional name. Until recently, this confusion of typification has puzzled some modern authors. For example, both P. praecox and P. humilis have been considered as types of the genus Pleione (Cribb et al., 1983; Cribb & Butterfield, 1988).

The two sections in Pleione are well defined and widely accepted. According to the International Code of Botanical Nomenclature (Greuter et al., 1994, Article 22.1), a name of any subdivision of a genus that includes the type of the adopted, legitimate name of the genus to which it is assigned is to repeat that generic name unaltered as its epithet. Therefore, the acceptance of Pfeiffer’s designation of Pleione praecox as the lectotype of the name Pleione, as by the Index Nominum Genericorum (Farr et al., 1979), automatically makes Pleione sect. Dictyopleione synonymous with Pleione sect. Pleione. This section, represented by P. praecox, includes the autumn-flowering species. The other section, typified by P. humilis, includes the spring-flowering species. The name Pleione sect. Humiles G. Zhu & S. C. Chen is here proposed for the latter section.

The current nomenclature and taxonomy of the genus Pleione may be summarized as follows:

Pleione D. Don, Prodr. Fl. Nepal. 36. 1825. TYPE: Pleione praecox (J. E. Smith) D. Don, Prodr. Fl. Nepal. 37. 1825 [Epidendrum praecox J. E. Smith, Exot. Bot. 2: 73. 1806], (lectotype, designated by Pfeiffer (1874: 754)).

Pleione sect. Pleione sect. Dictyopleione Pfitzer & Kraenzlin, in A. Engler, Das Pflanzenreich (IV. 50. II B. 7): Coelogyninae, 121. 1907. Nom. superfl.

1. Pleione lagenaria Lindley in Paxt., Fl. Gard. 2: 5. t.39. 1851. India (Assam).

2. Pleione maculata (Lindley) Lindley, Paxt., Fl. Gard. 2: 5. t. 39. 1851. Bhutan, Myanmar, China (Yunnan), India (Assam and Manipur), Sikkim, Nepal, and Thailand.

3. Pleione praecox (J. E. Smith) D. Don, Prodr. Fl. Nepal. 37. 1825. Bhutan, Myanmar, China (Yunnan and Xizang), N India, Nepal, and Thailand.

4. Pleione saxicola T. Tang & F. T. Wang ex S. C. Chen, Acta Phytotax. Sin. 25(6): 473, fig. 1. 1987. China (Yunnan).

Pleione sect. Humiles G. Zhu & S. C. Chen, sect. nov. TYPE: Pleione humilis (J. E. Smith) D. Don, Prodr. Fl. Nepal. 37. 1825.

Pseudobulbis ovoideis vel ampulliformibus, unifoliis, vere florens.

Flowering in spring; pseudobulbs ovoid to flask-shaped, narrowed gradually at the apex, 1-leaved (2-leaved in P. scopulorum), never mottled or warted; basal sheaths of the inflorescence smooth.

5. Pleione albiflora Cribb & C. Z. Tang, Curtis’s Bot. Mag. 184: 117. 1983. Myanmar, China (Yunnan).

6. Pleione bulbocodioides (Franchet) Rolfe, Orchid Rev. 11. 291. 1903. China (Anhui, Gansu, Guangdong, Guangxi, Guizhou, Sichuan, Yunnan, and Xizang).

7. Pleione chunii C. L. Tso, Sunyatsenia 1: 148. 1933. China (Guangdong and Yunnan).

8. Pleione confusa Cribb & C. Z. Tang, Curtis’s Bot. Mag. 184: 126. 1983. China (Yunnan).

9. Pleione coronaria Cribb & C. Z. Tang, Curtis’s Bot. Mag. 184: 123. 1983. Nepal.

10. Pleione formosana Hayata, J. Coll. Sci. Univ. Tokyo 30, art. 1: 326. 1911. China (Fujian, Jiangxi, Taiwan, and Zhejiang).

11. Pleione forrestii Schlechter, Notes Bot. Gard. Edinb. 5: 106. 1912. Myanmar and China (Yunnan).

12. Pleione grandiflora (Rolfe) Rolfe, Orchid Rev. 11: 291. 1903 (Oct.). China (Yunnan).

13. Pleione hookeriana (Lindley) B. S. Williams, Orch. Grow. Man. (ed. 6) 548. 1885. Bhutan, Myanmar, China (Guangdong, Guangxi, Guizhou,Yunnan, and Xizang), India (Assam), Laos, Nepal, Sikkim, and Thailand.

14. Pleione praecox (J. E. Smith) D. Don, Prodr. Fl. Nepal. 37. 1825. Myanmar, India (Assam and Manipur), and Nepal.

15. Pleione kohlsii Braem, Schlechteriana 2(4): 168. 1991. China (Yunnan). (= Pleione forrestii ´ P. chunii, hybr. nat.)

16. Pleione limprichtii Schlechter, Feddes Repert. Sp. Nov. Beih. 12: 346. 1922. Myanmar and China (Sichuan and Yunnan).

17. Pleione pleionoides (Kraenzlin ex Diels) Braem & H. Mohr, Orchis 65/66: 126. 1989. China (Guizhou, Hubei, and Sichuan).

18. Pleione scopulorum W. W. Smith, Notes Bot. Gard. Edinb. 13: 218. 1921. Myanmar, China (Yunnan and Xizang), and India (Assam).

19. Pleione yunnanensis (Rolfe) Rolfe, Orchid Rev. 11: 292. 1903 (Oct.). Myanmar and China (Guizhou, Sichuan, and Yunnan).

Key to the Sections of Pleione

1a. Flowering in autumn; pseudobulbs turbinate, 2-leaved (1-leaved in P. saxicola), often mottled or warted; basal sheaths of the inflorescence inflated or warted ...sect. Pleione

1b. Flowering in spring; pseudobulbs ovoid to flask-shaped, narrowed gradually at the apex, 1-leaved (2-leaved in P. scopulorum), never mottled or warted; basal sheaths of the inflorescence smooth ...sect. Humiles

Acknowledgment. We thank Richard K. Brummitt, Phillip Cribb, William D’Arcy, and Hong Song for help with the manuscript.

Literature Cited

Cribb, P. J. & I. Butterfield. 1988. The Genus Pleione. Timber Press, Portland, Oregon.

---, C. Z. Tang & I. Butterfield. 1983. The genus Pleione. Curtis’s Bot. Mag. 184: 93--147.

Don, D. 1825. Pp. 36--37 in Prodromus Florae Nepalensis. J. Gale, London.

Farr, E. R., J. A. Leussink & F. A. Stafleu. 1979. Index Nominum Genericorum (Plantarum), Vol. III: 1364. The Hague, Utrecht.

Greuter, W. G., F. R. Barrie, H. M. Burdet, W. G. Chaloner, V. Demoulin, D. L. Hawksworth, P. M. Jørgensen, D. H. Nicolson, P. C. Silva, R. P. Trehane & J. McNeill (Editors). 1994. International Code of Botanical Nomenclature (Tokyo Code). Regnum Veg. 131.

Pfitzer, E. & F. Kraenzlin. 1907. Pleione D. Don. In: A. Engler, Das Pflanzenreich IV. 50. (Heft 32): 119--129. Wilhelm Engelmann, Berlin.

Pfeiffer, L. 1874. Nomenclator botanicus 2: 754. Theodori Fischeri, Cassellis.