HARVARD PAPERS IN BOTANY 4(2): 431-433. 1999.

PLEIONE AUTUMNALIS (ORCHIDACEAE),

A NEW SPECIES FROM CHINA

SHINGCHI CHEN (XINQI CHEN)

Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Nanxinchun 20, Xiangshan, Beijing 100093, P. R. China.

GUANGHUA ZHU

Missouri Botanical Garden, P. O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.

Abstract. Pleione autumnalis, a new species from Yunnan Province, China, is described and illustrated.

Keywords: China, Orchidaceae, Pleione, taxonomy.

Pleione D. Don includes 19 species, 16 of which are found in China (Zhu and Chen, 1998). During the preparation of a treatment for the Flora Reipublicae Popularis Sinicae, an additional species was detected, and it is herein described as new.

Pleione autumnalis S. C. Chen & G. Zhu, sp. nov. TYPE: CHINA. Yunnan: Tengchong County, on way to Sadon near the Myanmar border, on rocks along Shito Ho; 7 November 1922, J. F. Rock 7281 (Holotype: OAO). Fig. 1.

Lithophytic herb. Pseudobulbs ovoid-conical or flask-shaped with an elongated neck (7 mm long), 2.5-4.0 cm long, 1.0-1.4 cm in diam., densely covered by remains of sheaths. Leaves 2, have fallen. Inflorescence appearing before the new leaves, erect, 1-flowered; peduncle 2-4 cm long, partly to completely covered by inflated sheaths; bract oblong-obovate, 1.8-2.2 cm long, 1.0-1.3 cm wide, usually crisped-erose toward the obtused apex, cymbiform and embracing the ovary; pedicel and ovary glabrous, 1.5-2.0 cm long, slightly shorter than or almost as long as the bract; flower 5-6 cm across, white; dorsal sepal oblong-oblanceolate, 3.3-3.7 cm long, 9-10 mm wide, subacute, 5- or 7-nerved; lateral sepals similar to dorsal sepal, slightly oblique; petals oblong-oblanceolate, 3.2-3.6 cm long, 8-9 mm wide, slightly oblique toward the acute apex, 5- or 7-nerved; lip 3-lobed in upper part, broadly ovate or suborbicular when flattened, 2.3-2.7 cm long, 2.4-2.8 cm wide; side-lobes erect, embracing the column, undulate-margined, with 2 or 3 broad stripes densely covered with minute warts on upper surface; mid-lobe subquadrate-ovate or subquadrate-orbicular, 1.0-1.2 cm long, 1.2-1.4 cm wide, undulate, neither ciliate nor lacerate on the margin, with 17 longitudinal rows of sparse papillae along the central veins, 5 of them running to the lower part of the lip; papillae suboblong, 0.5-0.7 mm long; column subclavate, 1.4-1.7 cm long, winged along both sides; wings broadened upward, notched and usually with 2 arm-like teeth toward the apexes. Capsule oblanceolateoblong, ca. 2.5 cm long, 7-8 mm wide.

Two sections are currently recognized in the genus (Cribb and Butterfield, 1988; Zhu and Chen, 1998). Pleione sect. Pleione includes all of the autumn-blooming species, and Pleione sect. Humiles includes all of the spring-blooming species (Zhu and Chen, 1998). Pleione autumnalis clearly belongs to sect. Pleione. It resembles P. maculata (Lindl.) Lindl. and P. lagenaria Lindl. in having two leaves and five to seven longitudinal rows of papillae along the central veins on the lip but differs in having ovoid-conical pseudobulbs with elongated necks up to 6-7 mm long, much shorter columns of 1.4-1.7 cm long, and much more sparse papillae along the central veins of the lip.

The type specimen of the described species consists of four plants and several flowers. It was identified by P. R. Hunt as P. grandiflora Rolfe, a spring-flowering species of Pleione sect. Humiles collected by A. Henry near Mentze (now Mengzi County) in southern Yunnan in 1898. Superficially these two look alike, but, besides the different flowering time, the latter has only one leaf, a coarsely lacerate apical margin of the flower lip, and lacerate lamellae. Judging from floral structures, P. autumnalis is more closely related to P. hookeriana (Lindl.) B. S. Williams. There is not enough evidence, however, to suggest that P. autumnalis is a hybrid between P. hookeriana and P. maculata or any other autumn-blooming species due to their different flowering periods.

ACKNOWLEDGMENTS

We thank the Missouri Botanical Garden and curator of OAO for the opportunity to examine the type specimen. We also thank David E. Boufford for help with the manuscript.

LITERATURE CITED

CRIBB, P. J., AND I. BUTTERFIELD. 1988. The Genus Pleione. Timber Press, Portland.

ZHU, G. H., AND S. C. CHEN. 1998. Humiles, a new section of Pleione (Orchidaceae). Novon 8: 461-463.