Dendrobium chrysotoxum

Dendrobium chrysotoxum Lindley

Languages: English

Overview

General Description

Stem pseudobulbous, erect, fusiform, 6-30 cm, 1.5-5 cm in diameter at middle, with 2-5 internodes, with many bluntly rounded ridges, golden-yellow when dry. Leaves 2-5, subterminal, oblong, to 19 cm long, 2-3.5 cm or wider, leathery, base contracted, not decurrent into clasping sheaths, apex acute and hooked. Inflorescence subterminal, ascending or slightly pendulous, to 20 cm, laxly many flowered; peduncle and rachis stout, basal sheaths 4 or 5; floral bracts ovate-lanceolate, 2-3 mm, membranous, apex acute. Pedicel and ovary to 5 cm. Flowers slightly fragrant, thickly textured, golden-yellow, lip deeper golden-yellow with red stripes on each side at base, anther cap pale yellow. Dorsal sepal oblong, 12-20 mm long, 5-9 mm wide at middle, 7-veined, slightly obtuse; lateral sepals nearly equal to dorsal sepal; mentum semiglobose, ca. 4 mm wide. Petals oblanceolate, ca. as long as dorsal sepal, ca. 2 times as wide as sepals, ca. 10-veined, margin minutely dentate, apex rounded; lip nearly reniform-orbicular, ca. 20-23 mm, adaxially densely pubescent, margin undulate, apex shallowly bilobed; disk often opposite V-shaped raised, sometimes with U-shaped chestnut spots. Column ca. 5 mm; anther cap tower-shaped.

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Description

Diagnostic Description

Dendrobium chrysotoxum is close relative of Dendrobium sulcatum, but differs from the latter in its stems not laterally compressed, thickly fusiform, with many ridges (vs. distinctly laterally compressed, clavate), petal margin minutely dentate (vs. entire), lip margin undulate (vs. minutely erose to ciliate-hairy).

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Genetics

The chromosomal number of Dendrobium chrysotoxum is 2n = 38 (Cheng et al., 1985; Hashimoto, 1987; Vijayakumar and Subramanian, 1994).

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Ecology and Distribution

Cyclicity

Flowering from March to May.

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Distribution

Dendrobium chrysotoxum is occurring in S and W Yunnan of China, NE India, Laos, Myanmar, Thailand, and Vietnam.

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Habitat

Epiphytic on tree trunks in sunny evergreen broad-leaved forests, lithophytic on rocks in open forests; 500-1600 m.

Author(s): Wen, Jun
Rights holder(s): Wen, Jun

Taxonomy

  • Callista chrysotoxa (Lindley) Kuntze (synonym)
  • Dendrobium chrysotoxum var. delacourii Gagnepain (synonym)

References

Cheng, S. J., Hu Z. H., Li X. L., & Chen R. Y. (1985).  A preliminary study on the chromosomes of Dendrobium in China. Acta Horticulturae Sincae. 12,
Hashimoto, K. (1987).  Karyomorphological studies of some 80 taxa of Dendrobium, Orchidaceae. Bulletin of the Hiroshima Botanical Garden. 9,
Vijayakumar, N., & Subramanian D. (1994).  Karyomorphological studies of Orchidaceae from Tamilnadu. Cell and Chromosome Research. 17,