Stichorkis distichis Thouars

Hermans, J., Verlynde, S., Cribb, P. et al. Malaxideae (Orchidaceae) in Madagascar, the Mascarenes, Seychelles and Comoro Islands. Kew Bull 75, 1 (2020). https://doi.org/10.1007/s12225-019-9851-0

Morphology General Habit

Medium-sized, erect epiphytic or lithophytic plant up to 20 cm high, on a short, branching rhizome, roots thin, wiry.

Vegetative Multiplication Pseudobulbs

Pseudobulbs ovoid to pyriform, more or less angular, 8 15 נ5 12 mm, covered with 3 5 lanceolate-acute sheaths, the upper ones longer (up to 25 mm), disintegrating with age, a single leaf at the apex.

Morphology Leaves

Leaf linear, bilobulate-acute at the apex, longly attenuate at the base, 12 20 נ0.9 1.5 cm.

Morphology Reproductive morphology Inflorescences

Inflorescence terminal, more or less arching, 8 18 cm long with up to 20 flowers.

Morphology Reproductive morphology Inflorescences Peduncles

Peduncle thin, about 2/32/3 of the inflorescence, with 1 3 amplectant sheaths.

Morphology Leaves Rachis

Rachis flattened, covered with prominent floral bracts, 1 5 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Floral bracts distichous, initially partly overlapping becoming distant with age, some without flower, greenish-yellow, persistent, oval acute, 3 6.5 נ1.5 1.8 mm.

Morphology Reproductive morphology Flowers

Flowers medium in size, overall av. 12 נ6 mm, 2 to 10, opening in succession, sepal and petals greenish yellow to orange, lip darker yellow to dark orange.

Morphology Reproductive morphology Flowers Pedicel and Ovary

Pedicel and ovary cylindrical, recurved at the base, 6 9 נ0.8 2 mm.

Morphology Reproductive morphology Flowers Calyx

Dorsal sepal reclined and almost parallel with the ovary, narrowly oval, acute, 4.5 7 נ2 2.5 mm. Lateral sepals descending, the margins recurved obliquely oval-acute, 5 7 נ2.1 3.2 mm.

Morphology Reproductive morphology Flowers Corolla

Petals erect, margins recurved, linear obtuse, 3.8 7 נ1.1 נ1.5 mm, sometimes a little wider at the tip.

Morphology Reproductive morphology Flowers Labellum

Lip pandurate, recurved at the base, the margins forming two rounded lobes, at the angular basal part carrying 2 small calli, the middle inflexed, the terminal part triangular-acute, recurved, 3.6 5.5 נ2 4.1 mm.

Morphology Reproductive morphology Flowers Column

Column triangular with the base very broad, wings triangular-acute towards the apex, 2.1 3 נ1.1 2 mm.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther oval, with a small lobule at the anterior margin, c. 0.4 נ0.5 mm.

Morphology Reproductive morphology Flowers Pollinia

Pollinia ovate, in two parts, c. 0.3 נ0.2 mm.

Morphology Reproductive morphology Seeds

Seed capsule ovoid, triangular, 8 10 נ4 5 mm.

Distribution

Comoros (Grande Comore, Anjouan), Mauritius and R鵮ion (Map 59).

Ecology

Dense humid forest, evergreen forest, locally forming small populations on tree trunks, main branches or rock in undergrowth. Altitude: 300 1400 m.

Conservation

Category LC: the extent of occurrence (EOO) of Stichorkis disticha is estimated to be 3,899,035 km2 (far exceeding the limits for Vulnerable status under criterion B1) whereas its minimal area of occupancy (AOO) is estimated to be 64 km2 (which falls within the limits for Endangered status under the criterion B2). With 11 known subpopulations representing 13 locations (sensu IUCN), this species has been preliminarily assessed as LC using the green listing method. This species is threatened by selective logging, timber harvesting for small-scale subsistence, slash-and-burn farming, grazing and anthropogenic fires, resulting in habitat reduction and habitat quality reduction.

Phenology

Throughout the year but mainly from December to March.

Note

Refers to the distichous habit of the rachis and floral bracts.