Angraecum idae Hermans & Sieder, Orchids (West Palm Beach) 90: 313 (2021).
Diagnosis:
Angraecum idae fits well in section Humblotiangraecum Schltr. (1925, p. 310), which is characterized by the short stem, several-flowered raceme, fleshy flowers with a short pedicel and a long thin spur. The species is distinct by the succulent lorate leaves that are strongly conduplicate; the short few-flowered inflorescence, angular peduncle and ovary carrying short scarious sheathing bracts; medium-sized flowers for the genus with a long spur, elliptic to obovate lip with a mucronate anterior margin and two round calli at the base.
Description:
Erect to arching, epiphytic or lithophytic herb up to 16 cm high. Roots basal, thick, slightly flattened against the substrate, more or less verrucose, 3-8 mm in diameter, silvery green when young, becoming silvery grey with age. Stem stout, short, very rarely branching, up to 5 cm long, 2-3 cm wide, more or less flattened, completely covered by overlapping leaf sheaths, the base carrying persistent, dark brown corrugate leaf sheath remnants. Leaves 3 to 5, basal, erectly spreading, articulate to and confluent with the leaf sheaths, succulent, narrowly elliptic, lorate, strongly conduplicate, 8.5-15 x 0.5 - 1.6 cm, V-shaped in cross-section, roundly ridged underneath, unequally roundly bilobed at the apex, pale to glaucous green. Inflorescence from the axis of the leaf sheaths, spreading, short, 2- to 3-flowered plus an embryonic bud. Peduncle short, angular in cross-section, distinctly keeled, slightly thickened at the join with the pedicellate ovary, circa (c.) 0.9-1.5 x 3-5 mm, persistent, with 1-2 thin, amplectant, reddish brown sterile bracts at the base. Floral bracts thin, ovate, conduplicate, dorsally ridged, attenuate, 5-6.4 x 1.2-1.5 mm, reddish brown. Flowers, overall 28-40 x 33-37 mm not including the spur; sepals and petals pale greenish-yellow becoming almost white on maturity, often pale green towards the base, lip white, all segments becoming pale ochre when fading, column, spur and ovary pale green, anther cap and pollen pale yellow. Pedicel and ovary angular-keeled, somewhat twisted longitudinally, curved towards the base of the flower, glabrous, 23-29 x 1.8-2.9 mm. Dorsal sepal narrowly ovate, 14.8-16.5 x 4.5-5.3 mm, attenuate, concave, slightly recurved; lateral sepals lanceolate, attenuate, 17.218.1 x 3.8-4.1 mm, the base overlapping the base of the spur. Petals lanceolate attenuate, 16.1-17.3 x 3.5-4.1 mm. Lip elliptic to obovate, anterior margin mucronate, 18-19.2 x 10.1-10.7 mm, flat, the margins slightly curved, with a central raised area and two distinct calli at the base by the entrance of the spur; spur incurved or sigmoid, slender, filiform, 85-92 mm long, 1.1-1.5 mm in diameter, narrowing towards the apex. Column c. 4 mm in diameter, wings oblong-truncate; lobule of the rostellum indistinct; anther cap galeate, with a raised rounded ridge on the exterior, auricular at the base, 2.12.3 x 2.5-2.7 mm; pollinia 2, pyriform, c. 1.1 x 1.3 mm, stipes indistinct with a small viscidium c. 0.5 mm long.
Etymology:
The epithet refers to Ida, the nymph of Greek mythology and to the name of the granddaughter of Christa and Anton Sieder, cofinders of the new species.
Habitat:
Epiphyte in forest remnants, on wet rock in pockets of humus. Altitude 120-630 m.
Phenology:
February to March.
Distribution:
Endemic to the Antsohihy area in Mahajanga Province, northern Madagascar.
References:
A new orchid from Madagscar by Hermans, Sieder, Rajaoyelona and Andriantiana Lindleyana.; 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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