Calanthe himalaicum Raskoti, 2019

Raskoti, Bhakta Bahadur & Ale, Rita, 2019, New species of orchids and notes on Orchidaceae of Nepal, Phytotaxa 394 (4), pp. 257-266 : 257-260

Calanthe himalaicum Raskoti sp. nov. Figs. 1 and 2 .

Type:— Nepal, Doti District, Wagalek, at an altitude of 2200 m, 24 August 2011, Raskoti Bhakta B. 0019 (holotype: KATH).

Diagnosis: Calanthe himalaicum is close to Calanthe arcuata ( Rolfe 1896: 196) but the former differs by its scape shorter or equal to leaves, petal lanceolate, lip unlobed, free from column wings, spurless, disk without any ridges, ovary and pedicel glabrous.

Herb terrestrial, whole plant 20–32 cm tall. Pseudostem sheathed, 3 cm long, 8 cm in diameter. Leaves 4–5, basal, narrowly lanceolate, 12–28 × 1.5–2.0 cm, apex acuminate, margin entire. Scape 20–27 cm long, arising from axil of leaf, slightly pendent, pubescent; raceme 6–9 cm with 3–5 lax flowered; floral bracts 10–15 × 2 mm, lanceolate, apex acuminate, persistent. Flower not opening widely, ca. 1.5 cm across, yellowish green, inner surfaces markings reddish brown; pedicel and ovary 1.0– 1.5 cm long, glabrous. Dorsal sepal 11 × 3 mm, lanceolate, slightly oblique, concave, 5-veined, only mid vein reaches at apex, apex acuminate; lateral sepals nearly similar to dorsal sepal 10 × 3 mm, obliquely oblong-lanceolate, slightly curved, 5-veined, only mid vein reaches at apex, apex acuminate. Petals 10 × 2 mm, obliquely lanceolate, concave, 3-veined, only mid vein reaches at apex, apex acuminate. Lip entire, free from column wings, 11 × 3 mm, oblong-lanceolate, base without ridges, 3-veined, apex acuminate to aristate; spur absent. Column 5 mm, flat. Fruit an ovoid capsule, 4-rigded, 1.5 cm long and 9 mm in diameter.

Flowering time: —August.

Habit, habitat and distribution: —Terrestrial in forest margins, grows in moist shady slopes. Taxon is known only from type locality in far-western Nepal at an altitude of 2200 meters. During the fieldwork in 2011, total forty individuals of C. himalaicum were observed in two different localities at the same altitude and habitat.

Etymology: — Calanthe himalaicum is the name of the type locality from Himalayan country Nepal.

Notes: — Calanthe himalaicum is close to Calanthe arcuata with which it shares the yellowish green flowers flushed with purplish brown markings (Rolf 1896). It is distinguished from C. arcuata by the scape equal or shorter than leaves, pedicel and ovary glabrous; petal lanceolate; lip entire, without spur, nearly similar to sepal and petal, base without ridges and free from column wings.

Another species Calanthe actinomorpha (Fukuy1935: 668) is similar to Calanthe himalaicum in lip shape (unlobed lip) but C. actinomorpha differs in having very dense and longer inflorecence, caducous floral bracts and lemon yellow flowers.

Figures

FIGURE 1. Calanthe himalaicum. A, Flowering plant; B, Flower; C, Dorsal sepal; D, Lateral sepal; E, Petal; F, Lip (All drawn by first author from the type specimen).

FIGURE 2. Calanthe himalaicum.A, Flowering plant; B, Flower; C, Dorsal sepal; D, Lateral sepal; E, Petal; F, Lip, G, Fruit.