Orchids of New Guinea

Prev Taxon: Genus Corybas section Gastrosiphon

Current Genus: Genus Corybas section Geosiphon

Next Taxon: Genus Corymborkis

Prev Species: Corybas umbonatus

Jump:

Corybas viridisepalus

Corybas viridisepalus S.P.Lyon, Malesian Orchid J. 18 (2016) 87, fig. 2-4.

Type: S.P. Lyon SPL 408 (holo LAE, iso L).

Terrestrial herb. Tuberoid ovoid, 0.7 by 0.6 cm. Stem slightly angular, c. 0.75 cm long; basal sheath 0.9 cm long; apex subulate. Leaf sessile, cordate, 1.3–1.6 by 1.1–1.2 cm, slightly rugose, glabrous; margins undulate; apex apiculate; nerves reticulate with two lateral nerves on either side of the midnerve,the outermost extending three-fourths of the way to the apex before anastomosing with the inner lateral veins. Peduncle less than 0.1 cm long. Floral bract narrowly triangular, 0.5–0.6 cm long; apex acute. Pedicel and ovary cylindrical, c. 0.35 cm long, ridged. Flower solitary, upright Median sepal spathulate-oblanceolate, 2.3 by 0.5 cm, glabrous, keeled; apex acute; 7-nerved. Lateral sepals filiform, c. 0.35 by 0.1 cm, emerging from behind spurs. Petals filiform, c. 0.3 by 0.1 cm. Lip from tubular basal part, abruptly curved downward and opening into a 0.9 cm wide, expanded oval blade, c. 1.6 cm long when flattened out, blade densely hispidulous, margins minutely fimbriate, apex incised, opening to floral tube V-shaped; spurs narrowly conical, c. 0.35 cm long. Column upright, 0.3 by 0.2 cm; ventral pad 0.2 by 0.1 cm. Fruit not seen.
(after Lyon 2016)

Colours:

Leaf deep green with paler nerves above, purple patches between nerves below. Peduncle greenish. Floral bract green. Median sepal pale translucent green. Lateral sepals and petals whitish. Outer surface of lip tube pale green with dark purple longitudinal streaks; spurs greenish-white; inner surface of lip blade pale green with 10 or more thin purple longitudinal stripes, these becoming irregular blotches in the centre of blade, and a thin purple margin. Ovary green.

Habitat:

Terrestrial in mossy montane forest. Altitude c. 2300–2900 m.

Distribution:

Malesia (New Guinea), endemic.

Distribution New Guinea:

Papua New Guinea (Enga and Jiwaka Provi.), see map

Cultivation:

Cool growing epiphyte.

Flowering time in the wild:

December

Classification:

Family Orchidaceae
Subfamily Orchidoideae
Tribe Diurideae
Subtribe Acianthinae
Genus Corybas
Species Corybas viridisepalus

Notes:

Corybas viridisepalus is closely related to theC. striatus (aff.), as evident from molecular data and presence of relatively short lateral petals and sepals, darkly striped lip blades, and dark green, cordate, rugose leaves with reddish markings below, held on a short stem close to the ground, but differs in the pale green floral background colour (versus white), the somewhat shorter lateral sepals and a more expanded lip blade which is more oblong than orbicular.