Angraecum cornigerum Cordem., Rev. Gén. Bot. 11: 418 (1899).
Homotypic Synonyms:
Pseudojumellea cornigera (Cordem.) Szlach., Mytnik & Grochocka, Biodivers. Res. Conservation 29: 21 (2013).
Description:
Plants epiphytic, erect or pendulous with age; stem sometimes branched, up to 500 mm long, covered with old leaf sheaths; leaf sheaths reticulate, rough; internode 10-20 mm. Roots few, sub-basal to basal, thick, verrucose, white-greyish. Leaves 4-12, erect, distichous, 30-80 x 2-4 mm, linear, coriaceous, rough, dark green with bluish tinge, slightly V-shape, sub-cylindrical, canaliculate on both sides, acute, sometimes recurved. Inflorescences 1 to 2, single-flowered. Peduncle 40-60 mm long, covered by 2 to 3 membranous sheaths; sheaths 3-7 mm long, striate, thin. Floral bracts (1—)6—7 mm long, semi-amplexicaul, striate, keeled. Flower resupinate, 40-70 mm diameter, white, sometimes with green tinge, slightly fleshy, nectariferous with only few drops of nectar present, odourless. Sepals 40-45 x 8-9 mm, narrowly-ovate, acuminate; similar to each other; median sepal slightly narrower than laterals. Petals 35 x 4 mm, narrowly-ovate. Labellum 35-40 x 18-25 mm, largely ovate, long-acuminate. Spur 130-150 mm long, filiform, pendent. Rostellum abnormally developed. Pollinia in direct contact with stigma (autogamy). Ovary (including peduncle) 40-60 mm long, narrow at the base. Capsule triquetrous, apex truncate, 30-40 x 18-22 mm, long lasting; peduncle 10 mm long.
Habitat:
Found in mid to high-elevation native forests in the north of the island, also in the calderas (‘cirque’), between 850-1950 m elevation (Fig. 3E). Usually growing as an epiphyte in the crown of canopy trees and difficult to detect. Although having a large elevational range, it occurs infrequently and in low densities in any given locality (Jacquemyn et al. 2007). The species is autogamous, with high fecundity and flowers are open for 1 to 2 days only. On Madagascar, the putative specimens were collected in the central highland (Andriananjamanantsoa et al. 2016), in an area where small native vegetation patches survive within a matrix of anthropogenic landscape (Andriananjamanantsoa, pers. comm., 14 April 2020).
Phenology:
Flowering in November and December.
Notes:
Superficially this species seems very similar to Angraecum chimanimaniense (section Perrierangraecum) from Zimbabwe but is clearly distinguished by the long slender peduncle which is quite bare below the bract.
Distribution:
Réunion, ?Madagascar. The species is likely present on Madagascar (Andriananjamanantsoa et al. 2016), but collection of flowering material is necessary to determine its identity.
References:
Cultivated Angaecoid Orchids Hillerman/Holst 1986; Angraecoid Orchids Stewart, Hermans and Campbell 2006; Revision of Angraecum sect. Perrierangraecum (Orchidaceae; Epidendroideae; Vandeae) for the Mascarenes, with a description of a new endemic species for Mauritius; POWO (2022). "Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; http://www.plantsoftheworldonline.org/ Retrieved 21 November 2022."
Images:
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