AFRICAN

ORCHIDS

Malaxis cardiophylla (Rchb.f.) Kuntze, Revis. Gen. Pl. 2: 673 (1891).
Homotypic Synonyms:
Microstylis cardiophylla Rchb.f., Flora 68: 543 (1885).
Orestias cardiophylla (Rchb.f.) Marg., Ann. Naturhist. Mus. Wien, B 107B: 218 (2005 publ. 2006).
Description:
Small, terrestrial, lithophytic or epiphytic tufted plant 5.5 – 10 cm high, on a very short, occasionally branching rhizome, roots fibrous. Pseudobulbs slender, caulescent, 20 – 60 × 3 – 5 mm, covered by 3 – 4 membranous sheaths, generally carrying two leaves, sometimes accompanied by a third smaller leaf, leaves persistent on previous growths. Leaves thin, broadly cordate, more or less unequally lobed at the base, shortly acute at the tip, with a short 6 – 12 mm petiole, 1.8 – 3 × 1.3 – 2 cm. Inflorescence erect, thin, 6 – 10.5 cm, with 7 – 23 flowers. Peduncle short, with 3 – 5 bract-like sheaths. Rachis loosely racemose, flowering in succession hardly 1 – 2 cm above the upper leaf. Floral bracts erectly spreading, narrowly lanceolate to cordate-triangular, 2.5 – 5 × 0.9 – 1.1 mm. Flowers small, 5 – 6 mm including the ovary, violet or purplish, the lip green with a yellow callus. Pedicel and ovary glabrous, 3 – 3.5 × 1.1 – 1.3 mm. Dorsal sepal oval-lanceolate, obtuse, 1.9 – 2.8 × 0.7 – 1.2 mm. Lateral sepals ovate, obtuse, 2 – 2.8 × 1 – 1.3 mm. Petals linear, obtuse, narrowed towards the apex, 2.1 – 2.7 × 0.5 – 0.6 mm. Lip oblong, obtuse and sinuate at the anterior margin, broadly winged at the base not surpassing the column, the disk with two rounded minutely pubescent longitudinal ridges, 1.5 – 2.1 × 1.6 – 2 mm. Column slender, up to c. 1.1 × 0.3 mm, the apical wings triangular-acute, ascending. Anther ovate with a rounded anterior lobe, c. 0.6 × 0.8 mm. Pollinia ovate 0.8 × 0.5 mm.
Etymology:
A reference to its heart-shaped leaves.
Recognition:
Malaxis cardiophylla is a small plant with two, broadly cordate, persistent leaves with a long petiole, a loosely racemose rachis, with up to 20 small flowers, an oblong, broadly lobed, obtuse lip, with two longitudinal vein-like ridges.
Malaxis cardiophylla is similar to M. weberbaueriana but the plant and flowers are distinct, especially the leaves which are cordate (vs lanceolate) and a lip which is broader and does not surpass or envelop the column. A drawing by Ridley (at K) based on Humblot 437 (presumably based on the BM specimen), shows differently shaped (not cordate) leaves. Perhaps M. cardiophylla is an aberrant or local form of M. weberbaueriana but based on current evidence it is left as a separate entity. It is also similar in lip-shape to M. atrorubra but it is broadly vs narrowly winged, its habit and leaf shape are slightly different with a broadly cordate leaf vs ovate with the base oblique, and its column structure with rounded (vs angular) lobes.
Habitat:
Near rock, in forest, terrestrial or epiphytic. Altitude: around 300 – 400 m.
Flowering time:
December to January.
Distribution:
Comoros (Njazidja)
References:
Malaxideae (Orchidaceae) in Madagascar, the Mascarenes, Seychelles and Comoro Islands Kew Bulletin volume 75, Article number: 1 (2020)
Images:
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