AFRICAN

ORCHIDS

Platanthera azorica Schltr., Repert. Spec. Nov. Regni Veg. 16: 378 (1920).
Homotypic Names:
Habenaria longebracteata Hochst. ex Seub., Fl. Azor.: 25 (1840).
Platanthera micrantha var. longebracteata (Hochst. ex Seub.) Soó, Arch. Bot. (Leipzig) 23: 104 (1928).
Limnorchis longebracteata (Hochst. ex Seub.) Efimov, Novosti Sist. Vyssh. Rast. 40: 50 (2008 publ. 2009).
Description:
Tubers broadly fusiform, narrowing to a single, long, fleshy apical root; a further 2–4 roots emerge horizontally from the base of the stem; old and new tubers separated by a substantial stolon 30–50% the length of the tuber. Stem 20 ± 10 cm, 3.8 ± 2.0 mm in diameter. Sheathing leaves usually 2, occasionally 1, largest 111 ± 64 mm × 40 ± 24 mm, broadly ovate/obovate, spreading and lacking an elongate petiole; bracteoidal leaves 1.8 ± 1.4, usually distributed fairly evenly along stem and grading into basal bracts. Inflorescence 85 ± 46 mm, 18± 11 flowers (4.7 ± 2.8 fls/cm). Basal bracts 28 ± 17 mm, floral bracts 18 ± 7 mm × 5.4 ± 1.8 mm, lanceolate; marginal cells rounded, 51 ± 16 µm in longitudinal diameter. Flowers uniformly agathia green (RHS 142B, C in natural light, 140A–144D in artificial flash); median sepal forms an operculum over the lateral petals, which project directly forward, together forming an ‘awning’ above the gynostemium. Labellum occasionally paler toward spur entrance, entire, 8.3 ± 2.0 × 2.4 ± 0.5 mm, linear-lanceolate, recurved moderately to strongly backward and also curved gently to moderately backward. Spur 9.5 ± 1.8 mm long × 1.4 ± 1.1 mm in diameter at mouth, 1.1 ± 0.5 mm midway along its length, strongly or occasionally moderately down-curved; spur entrance ± equidimensional rather than compressed vertically. Ovary 14.0 ± 2.8 mm. Lateral sepals oriented closer to horizontal than vertical, 8.2 ± 1.8 × 3.6 ± 0.9 mm. Lateral petals 5.7 ± 1.7 mm. Gynostemium 3.2 ± 1.0 mm long × 3.5 ± 0.8 mm wide; stigma immediately above spur entrance, a horizontally elongate crescent, 2.7 ± 1.0 mm wide; rostellum a subdued, elongate crescent; auricles lateral to, and largely fused with, remainder of gynostemium, comparatively large, 0.8 ± 0.9 mm. Anther locules linked by a wide, well-developed connective, robust, locule aperture sigmoid, relatively taut; paired pollinaria 2.5 ± 1.1 mm, slightly to moderately convergent from viscidium to pollinium apex, viscidia separated by 3.1 ± 0.7 mm, apices of pollinaria by 2.2 ± 0.6 mm; viscidia ± opposed, orbicular, obscurely bipartite; caudicle proximally geniculate, terete, ± equalling the pale yellow pollinium; pollinium bears several vertical rows of massulae. Fragrance comparatively subtle, of musk and spice.
Habitat:
Alpine grassland and open, dwarfed laurisilva scrub at ca 950–1000 m asl.
Distribution:
Azores (São Jorge)
References:
Systematic revision of Platanthera in the Azorean archipelago: not one but three species, including arguably Europe’s rarest orchid by Richard M. Bateman,corresponding author Paula J. Rudall,1 and Mónica Moura