Aeranthes campbelliae Hermans & Bosser, 2003

Hermans, Johan & Bosser, Jean, 2003, A new species of Aeranthes (Orchidaceae) from the Comoro Islands, Adansonia (3) 25 (2), pp. 215-217 : 215-217

Aeranthes campbelliae Hermans & Bosser , sp. nov.

Affinis Aeranthes ecalcarata H. Perrier sed habitu majore, foliis oblongis 3-8 mm latis in flabello dispositis, inflorescentiis 2-4-floribus, bracteis maioribus 3 mm longis, labello ovato calcari obscure conico satis distinguenda.

TYPUS. — Hermans 3915, Comoro Islands (holo-, K!) .

A small-sized erect epiphyte, up to 90 mm tall. Stem simple, leafy, flattened, 2-3 mm in diam.; roots 1 mm in diam., smooth. Leaves 3-6, persistent, narrowly oblong, 40 to 62 mm long, 3 to 8 mm broad. Inflorescences several, racemose, 2- to occasionally 4-6-flowered, with an undeveloped terminal bud, erect, axillary; peduncle wiry, terete, up to 85 mm long, 0.6 mm in diam., normally simple, occasionally few-branched, with at the base a tubular sheath 4-6 mm long, 0.8 to 1 mm wide, bearing above 2-3 further sheaths partly covering the internodes; floral bracts 3 mm long, 1 mm wide. Flowers 12-14 mm tall, 9- 11 mm wide, 8 mm deep, translucent greenishwhite, with a few microscopic black specks on the exterior, the lip and tails of petals and lateral sepals more yellowish-white, column green; tepals with 3 obscure veins and a few shorter veinlets towards the margin; ovary pedicellate, 7 mm long, 0.9 to 1.2 mm at the widest point, roundly ridged, with some small dark-brown specks towards the base. Dorsal sepal 11 mm long, 3 mm wide, oblong-ovate, tip slightly obtuse, erect to slightly leaning forward. Lateral sepals spreading, 11 mm long, 4 mm wide, ovate, long acuminate into a tail c. 6 mm long. Petals slightly reflexed at the tip, 9 mm long, 2.8 mm wide, ovate, long acuminate into a tail c. 3 mm long. Lip broadly oval, 4.6 mm long, 3.8 mm wide, articulate to the column-foot, mobile, auriculate at the base, forming two rounded swellings, base of the disk farinose and papillose, with three central veins converging toward the tip, a further 2-3 veins branching towards the margin; spur very short, rounded and almost indistinct from the column-foot and mentum, 1 × 1 mm. Column short and semi-rectangular, somewhat thickened at the apex, 1.2 mm long, 0.9 mm broad, 1 mm high; rostellum indistinctly bi-lobed; column-foot boat-shaped, very slightly inflated and continuous with the short spur; anther cap 0.8 mm wide, 0.8 mm high, white, membranous and globular; pollinia porate, globular, 0.3 mm in diam., with a short thread-like viscidium, waxy, yellow. Fruit unknown.

DISTRIBUTION. — Endemic to the Comoro Islands, Grande Comore.

ETYMOLOGY. — Named for Heather CAMPBELL, who propagated plants of this new species, originally collected by Mrs. Jean CLASSEN.

Aeranthes campbelliae has flowers similar in shape to those of Aeranthes ecalcarata H. Perrier , which is endemic to Madagascar and the only other species of the genus lacking a distinct spur. Although several collections of A. campbelliae have flowers that are larger than those of the Madagascan species, those of some other specimens are almost identical in size. The main difference between the two species is in the leaves and the inflorescences. In A. ecalcarata the leaves are narrowly linear, canaliculate on top, and the inflorescences have very slender peduncles with a few sheaths only and bearing 1 to 2 flowers at the tip. In A. campbelliae the leaves are fan-shaped and narrowly oblong, and the inflorescences have a more robust raceme with more prominent sheaths, sometimes bearing more flowers. One could regard the Comorean plant a subspecies of A. ecalcarata , but considering its important differences in the inflorescence and the leaves, it is described here as a distinct species.