香港绶草 xiang gang shou cao

Plants 11-44 cm tall. Roots 1.5-3.5 mm in diam. Leaves 2-6, erect and spreading, linear to oblanceolate, 4-12 × 0.5-0.9 cm, apex acute. Inflorescence erect, 10-42 cm, becoming densely glandular pubescent distally; rachis 3.5-13 cm, with many spirally arranged flowers; floral bracts lanceolate, sparsely glandular pubescent, apex acuminate. Flowers creamy white; ovary green, ca. 4 mm, glandular pubescent. Dorsal sepal forming a hood with petals, oblong, cymbiform, ca. 4 × 1.5 mm, outer surface glandular pubescent, apex obtuse; lateral sepals oblong-lanceolate, slightly oblique, ca. 4 × 1.5 mm, outer surface glandular pubescent, apex obtuse. Petals sometimes tinged pale pink, oblong, slightly oblique, ca. as long as dorsal sepal, thinly textured, apex obtuse; lip broadly oblong, 4-5 × ca. 2.5 mm, basal portion thickened and with 2 transparent, spherical glands, lateral margins erect and crisped, apex truncate-obtuse and recurved; disk papillate. Column erect, ca. 1 mm; anther ovoid; pollinia ca. 1 mm; rostellum triangular-lanceolate; stigma slightly raised, shield-shaped, distinctly 3-lobed. Fl. Mar-Apr. 2n = 60*.

● Open moist to dry hillsides, grasslands, meadows; 800-900 m. Hong Kong.

Since it was first described, this species has largely been ignored by subsequent authors who have referred it to synonymy of Spiranthes sinensis. However, Hu and Barretto (Chung Chi J. 13(2): 4-6. 1976) identified the often densely glandular pubescent rachis, glandular pubescent floral bracts and sepals, and the broad, distinctly 3-lobed stigma as clear morphological characters that distinguish it from S. sinensis. More recently, Sun (Amer. J. Bot. 83: 252-260. 1996) demonstrated that S. hongkongensis is an allopolyploid probably derived from natural hybridization between S. sinensis and S. spiralis (Linnaeus) Chevallier. Though S. hongkongensis has only been confirmed from Hong Kong to date, it is likely to be more widespread, particularly where the two parental species are sympatric; re-examination of herbarium material may result in the revoking of its endemic status, and synonymy may have to be re-assigned.