AFRICAN

ORCHIDS

Microcoelia gilpinae (Rchb.f. & S.Moore) Summerh., Bot. Mus. Leafl. 11: 153 (1943)
Homotypic Synonyms:
Angraecum gilpinae Rchb.f. & S.Moore, J. Linn. Soc., Bot. 16: 206 (1877).
Gussonea gilpinae (Rchb.f. & S.Moore) Ridl., J. Linn. Soc., Bot. 21: 491 (1885).
Epidorchis gilpinae (Rchb.f. & S.Moore) Kuntze, Revis. Gen. Pl. 2: 660 (1891).
Mystacidium gilpinae (Rchb.f. & S.Moore) T.Durand & Schinz, Consp. Fl. Afric. 5: 52 (1894).
Rhaphidorhynchus gilpinae (Rchb.f. & S.Moore) Finet, Bull. Soc. Bot. France 54(9): 34 (1907).
Heterotypic Synonyms:
Gussonea gilpinae var. minor Schltr., Beih. Bot. Centralbl. 34: II (1916).
Gussonea melinantha Schltr., Repert. Spec. Nov. Regni Veg. Beih. 33: 377 (1925).
Microcoelia melinantha (Schltr.) Summerh., Bot. Mus. Leafl. 11: 155 (1943).
Description:
Stem short, up to 20x2—3(^4) mm. Scale-leaves acute, with 5-7 nerves, ± splitted when old. Roots few, slender, variously spreading, usually twisted, distally with few branches, terete, smooth, up to 40 cm x 1.0-1,5(—2.0) mm. Inflorescence(s) erect, spreading, up to 45 mm long, up to 3—4(—15) simultaneously, usually densely flowered at the outermost 1 /2—1/3(—1/6) of the total length, each with up to 10(—20) flowers; peduncle distinct, terete, up to 40 mm long; rachis straight, ± terete, slightly angular at the flower joints, indistinctly flexuose, greenish; bracts sheathing, acute, rarely obtuse, with 1 nerve, up to 2 mm long, ± transparent yellowish brown. Pedicel long, straight or slightly curved, up to 9.5 mm long, greenish or orange-yellow; ovary straight, (1.3—)1.8—3.2 (-4.3) x 0.4-0.8 mm, greenish fading into orange-yellow distally or orange-yellow. Flowers ± erect, spreading, up to 19 mm long including ovary and pedicel; orange-red or orange-yellow. Glandular hairs present or not, if present sparsely scattered on pedicel, ovary and the basal parts of the tepals. Dorsal sepal ± hooded, elliptic to oblong, obtuse to subacute, with (I-2-) 3 nerves, (2.0-)2.7-3.9(-4.5) x 1.3-2.0 (-2.5) mm. Lateral sepals asymmetric, ± ovate, convex, acute, subapiculate, lower base extended, rounded, ± connate below ovary, with (1-2-) 3 nerves, (3.1-)3.4-4.6(-5.0) x (1.9-)2.4-3.2 mm. Petals ± obovate, acute, subapiculate, with (1—2—)3 nerves and occasionally with indistinctly branched nerves, 2.6—3.6(—4.1) x (1.4—) 1.6-2.2 (-2.6) mm. Labellum obovate to suborbi-cular, ± calceolate, margins ± infolded and ± uneven or minutely erose, apex ± incurved and sometimes extended into a small prolongation with 5 main nerves, lateral nerves branched, spur mouth constricted by a ± ringformed thickening and at each side sometimes with an indistinct protruding thickening, (2.0-)2.3-3.5(-4.0)X (1.2—) 1.6—2.1 (—3.0) mm spur long, cylindrical, ± appressed to the ovary and pedicel, slightly sigmoid in outline with the basal part distinctly incurved, ± inflated and sometimes pouch-like, tapering apically to an obtuse or a spherically inflated apex, (5.4—)6.3—8.8(—9.5) mm long, at the base up to 13 mm wide, apical inflation up to 0.9 mm in diameter. Column elongated, straight or slightly recurved, 0.8—1.7(—2.6) mm long, 0.4—1,2(—1.9) mm high; androclinium slightly excavated, with a central slightly raised angular-ovate area; rostellum-lobes porrect or slightly recurved, acute, at the base with 2 minute membranous wedge-shaped lobes, (0.5-)0.6-0.9 mm long. Anther hemispherical in side view and slightly bivalved at the base, tapering into a narrow beak-shaped apex, ± acute to truncate, ± recurved, 1.2—1.8(—2.0) x 0.6—0.9(—1.1 ) mm. Pollinia subglobose, asymmetric; in side view circular to elliptic, with ± flattened facets, (390-)470—490(-630) x (360-)430-450(-590) µm; in median section ± ovate, unequally flattened, up to 450 µm thick. Stipes ± straight from a curved base, rigid, channelled, with an obtrian-gularly capitate apex, tapering into a very narrow base, 1.0—1.4(—1.6) mm long; viscidium convex, ± obovate, obtuse, with a ± truncate base, 0.6-0.8 x 0.3—0.5(—0.6) mm. Capsule ellipsoid, straight, c. 8 x 4—5.5 mm; pedicel distinct, up to 9.5 mm long. Seeds fusiform to ± bottleshaped, testa cells narrowly elongate (in a dry state), with ± club-shaped and loop-shaped or with few hook-shaped processes; anticlinal walls ± sulcate with finer striations, sometimes indistinctly spirally sculptured, terminal ends elongated, proximal end obtuse with a ± pointing distal end, (570-)600-690(-750) x (40-)50-70 µm. Scent not percepted.
Etymology:
Named in honour of Helen Gilpin (1834-1907), a British missionary teacher in Antananarivo (1869-1895), who collected plants for herbarium
Habitat:
Dense rain forest and in secondary vegetation; epiphytic on various understorey vegetation, often attached to almost nothing. Expanded cobweb-shaped formations are often found, sometimes (densely) covered with mosses. Altitude. 200-1800 m.
Flowering period:
Throughout the year, with a tendency of concentration to the transitions to the main rains.
Cultivation:
As given for the genus, hot to cool growing epiphyte.
Notes:
This species may be recognised by the marked almost naked peduncle which is usually as long as, if not longer than, the flower-bearing part of the inflorescence. The column is also remarkable, the rostellum curving up in front so as to form in continuity with the sloping androclinium a sickle-shaped apex to the column along which lies the stipes of the pollinia. The lip is very concave and almost impossible to flatten out while the spur is incurved for a short distance at its base; it is shorter and thicker than in Microcoelia elliott (Finet) Summerh.
Distribution:
Madagascar
References:
Flora of Madagascar Perrier 1981; A Monograph of the Genus Microcoelia [Orchidaceae] Jonsson 1981; AOS Bulletin Vol 74 No 11 2005; Angraecoid Orchids Stewart, Hermans, Campbell 2006; Orchids of Madagascar Hermans 2007; Field Guide to the Orchids of Madagascar Cribb & Herman 2009; WCSP (2017). 'World Checklist of Selected Plant Families. 03.03-2017; http://apps.kew.org/wcsp/
Images:
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Habitat/In situ Habitat/In situ Habitat/In situ
Microcoelia gilpinae 01 Microcoelia gilpinae 02 Microcoelia gilpinae 03
Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission. Photograph ©Gilles Grunenwald. Image used with kind permission.