Angraecum liliodorum Frappier

Pailler, Thierry, Verlynde, Simon, Bytebier, Benny, Florens, F. B. Vincent & Baider, Cláudia, 2020, Revision of Angraecum sect. Perrierangraecum (Orchidaceae; Epidendroideae; Vandeae) for the Mascarenes, with a description of a new endemic species for Mauritius, Phytotaxa 442 (3), pp. 183-195 : 192

5. Angraecum liliodorum Frappier in Jacob de Cordemoy (1895: 198). ( Fig. 2B )

Homotypic synonyms:— Jumellea liliodora (Frapp.) Schlechter (1915: 429) ; Perrierangraecum liliodorum (Frapp.) Szlach., Mytnik & Grochocka in Szlachetko et al. (2013: 20). Type :— RÉUNION. Grand Tampon, Cordemoy s.n. (lectotype P00750176 !, suggested by Bosser with a det. slip on the specimen, here designated) .

Description:— Plants epiphytic, upright or pendulous; stem (10–)20–80(–100) mm long, covered with old leaf sheaths; internodes 0.5–0.8 mm. Roots basal, few, thick, smooth, white. Leaves 3–7(–9), distichous, 30–60 × 12–15 mm, oblong-elliptic, thick, coriaceous, shiny dark green, V-shaped, apex unequally bilobed, slightly granulose, margin slightly wavy. Inflorescences 1–3, single-flowered. Peduncle 6–8 mm long, twisted, 3-angled; covered by 1 to 2 membranous sheaths. Floral bracts 14–16 mm long, ovate, keeled at back. Flower resupinate, 40–60 mm in diameter, creamy to yellowish white, sometimes with green tinge; fleshy, sweetly scented at all times, nectariferous. Sepals 28 × 5 mm, narrowly-ovate, similar to each other, acuminate, 7–9-veined; median sepal slightly less wide and shorter than laterals, acute, 7-veined. Petals 22–26 × 3–4 mm, similar to sepals, 5-veined. Labellum 23–25 × 12–14 mm, largely ovate, rarely elliptic or nearly cordate, acuminate, white. Spur 50–60 mm, filiform, pendulous. Anther cap 2.5–3.0 mm, keeled in front. Column 3–4 mm high, fleshy, auricles 1.5 mm, oblong-truncate. Ovary 10–14 mm long, thick. Capsule triquetrous, 3 × 10–12 mm, long lasting; peduncle 6–8 mm long, thick.

Distribution:— Réunion.

Habitat and ecology:— This species occurs in native semi-dry to wet forests between 50–500(–700) m elevation, from the north-west to the south-east of the island ( Fig. 3F ). The species is, most probably, pollinated by a hawk moth ( Sphingidae ) and has a low fruiting success.

Phenology:— Flowering from January to March in the semi-dry forest and from May to June in the wet forest.

Conservation status:— This species is not common ( Jacquemyn et al. 2007) and is the rarest member of A. sect. Perrierangraecum on Réunion. It is found in few localities and in low density, mostly at the base of trees or on large tree branches. As the species is known from an Area of Occupancy of 20 km 2, with a small Extent of Occurrence (554 km 2), within habitats being progressively invaded by alien plants, it should be considered Endangered (EN B1ab(iii)+B2ab(iii)).

Additional specimens examined:— RÉUNION. Grande Chaloupe, 450 m, March 1973, fl., Friedmann 2158 ( P00754491 ) ; Ravine de la Grande Chaloupe, 1 March 1978, fl., Bosser 22350 ( P00754490 ) ; St Philippe, Mare Longue, Réserve Biologique, 200 m, fl., Cadet 3239 ( P00754492 ) ; Ile Bourbon, s.d., fr., Delteil s.n. ( P00754489 ) .

Figures

FIGURE 2. Angraecum sect. Perrierangraecum of the Mascarenes.A. Angraecum cucullatum. B. Angraecum liliodorum. C. Angraecum cornigerum. D. Angraecum borbonicum. E. Angraecum baiderae. Photos: A, C, D. Frederic Henze; B. François Vandeschricke; E. F.B. Vincent Florens.

FIGURE 3. Distribution of the five species of Angraecum sect. Perrierangraecum on the islands of the Mascarenes. A. Angraecum baiderae (Mauritius). B. Angraecum borbonicum (Réunion). C. Angraecum cucullatum (Réunion). D. Angraecum cucullatum (Mauritius). E. Angraecum cornigerum (Réunion). F. Angraecum liliodorum (Réunion).