Eulophia epiphytica P.J. Cribb, D. Du Puy & Bosser, 2002

Eulophia epiphytica P.J. Cribb, D. Du Puy & Bosser View in CoL , sp. nov.

Affinis Eulophiae palmicolae H. Perrier sed pseudobulbis carentibus caulibus cylindraceis non dilatatis pendulis ramosis vaginibus obtectis, foliis pluribus linearibus distichis, inflorescentiis lateralibus pendentibus quam foliis brevioribus flores 2-9 ferentibus, sepalis petalisque acutis viridibus vel luteo-viridibus, lobo medio labelli emarginato et calcare breviore 2 mm longo distinguenda.

TYPUS. — Du Puy, Cribb, Andriantiana & Ranaivijaona M857, Madagascar, Toliara Province, 7 km N of Taolanaro, Ampasinahampoana , 7 Feb. 1995, cult. Kew 15 May 2001 (holo-, K!; iso-, P!, TAN!) .

A large epiphytic herb with pendent or trailing branching cylindrical stems, up to 1.5 m long, 0.7 cm in diam., leafy in upper part and partly covered by acute papery sheaths up to 2.7 cm long in lower half. Leaves 28-32, thin, flexible, linear, acute, 10-25 cm long, 1-1.2 cm wide, articulated with 1.5-3 cm long whitish sheaths at the base. Inflorescences several per stem, lateral, 2-9-flowered, arcuate to pendent; peduncle 3-7 cm long, almost covered by short acute sheathing sterile bracts; rachis 1-4 cm long; bracts lanceolate, acute, 3-8 mm long.

Flowers spreading, distinctively fragrant, c. 3- 3.5 cm broad, with green or yellowish green sepals and petals, lip white turning pale yellow with age, marked on the base of the midlobe with purple veins, side lobes green with dark purple veins; pedicel and ovary 2.1-2.7 cm long. Dorsal sepal elliptic, acute, 2.2-2.4 cm long, 0.7-0.8 cm wide. Lateral sepals spreading, oblong-elliptic, acute, 2.5-2.7 cm long, 0.7-0.75 cm wide. Petals slightly obliquely elliptic, acute, apically slightly recurved, 1.8-2.3 cm long, 0.8-0.9 cm wide. Lip 3-lobed, shortly spurred at the base, 1.8-2 cm long, 1.6-1.8 cm wide; side lobes erect, obliquely oblong, rounded and slightly recurved in front; midlobe transversely oblong, slightly emarginate, slightly recurved in front, 8 mm long, 14 mm wide; callus of three to five ridges on disc, coalescing towards the base, two or four outer keels erose in front, with outer veins of midlobe also erose-papillose; spur shortly conical-cylindrical, 2 mm long. Column slightly sinuous, 8.5-9 mm long, foot 2 mm long; anther cap with a distinct terminal knob; pollinia 2, deeply porose, stipe short, fleshy, viscidium semilunate. — Fig. 1. View Fig 1

HABITAT. — Epiphytic on Elaeis guineensis , Raphia farinifera and probably also on Dypsis palm trees, climbing amongst leaf bases on trunk of palm; sea level- 100 m.

IUCN CONSERVATION STATUS. — Critically endangered (CR). Based upon IUCN Red List criteria A1a, c; B1; 2c, e; C2b.

Eulophia epiphytica is a very distinctive orchid. The only other epiphytic species of Eulophia is the Madagascan E. palmicola H. Perrier but that species has three- or four-leaved pseubobulbous stems on a short rhizome, long erect inflorescences as long as the leaves and flowers with apiculate sepals and petals, a lip with a 2-ridged callus at the base, a shortly apiculate midlobe and a 4 mm long spur. The type of Eulophia palmicola (Perrier de la Bâthie 18893, P!) was collected in southeast Madagascar between Manambovo Riv. and Menarandra Riv., growing on the palm Ravenea xerophila Jum .

Eulophia epiphytica is apparently very restricted in its distribution in the southeast corner of the island, not far from Taolanaro (Ft. Dauphin) where it is most frequently seen on oil palms, Elaeis guineensis and on raffia palms, Raphia farinifera . The avenue of oil palms where the type collection was made is next to a swampy plantation of Raphia farinifera . Eulophia epiphytica grows on both palms in the immediate area. The reference in DU PUY et al. (1999) to Eulophia palmicola being found on Raphia refers rather to this species. Raphia farinifera is almost certainly an introduction from tropical Africa, being always found growing near villages or in plantations in Madagascar ( DRANSFIELD & BEENTJE 1995). Oil palm is also an introduction in this area but may be native elsewhere in Madagascar (DRANSFIELD, pers. comm.). The orchid grows with the bases of its stems running through the leaf bases of the palms with the leafy stems of the orchid hanging in a curtain from all around the palm stem. Its natural host cannot be Ravenea xerophila , the palm that hosts E. palmicola , which is rare, reduced to about 65 mature trees and only grows in the dry spiny Didieriaceae/ Euphorbia forests on laterite and gneiss between 200 and 700 m elevation ( DRANSFIELD & BEENTJE 1995). That is a much drier habitat and well removed from the type locality of E. epiphytica .

John DRANSFIELD (pers. comm.) suggests that Beccariophoenix madagascariensis Jum. & H. Perrier and Dypsis fibrosa (Wright) Beentje & J. Dransf. , both found in suitable habitats nearby, might be searched for the orchid. The crown of the former may be a suitable habitat for the orchid but we have examined all of the trees in the southern population which is slightly north of the type locality of E. epiphytica and this orchid was not found there. Dypsis fibrosa is a known host of other epiphytic orchids and is a widespread species. In the region it can be found in littoral and lowland peat-swamp forests on white sand. It seems the likeliest native host for the orchid. Another possibility is that it might grow on Pandanus , a host elsewhere for orchids.

Conservation status

The only known population, and a large one, of this extraordinary orchid grows in a swampy Raphia and oil palm plantation abutting the main road not far north of Taolanaro (Ft. Dauphin). Unfortunately, most of the plantation was destroyed due to development in the mid 1990s and only a few palms survive along the roadside. The orchid survives there but in very reduced circumstances, probably less than 100 plants. It is a showy species and it has only ever been found in the type locality. Its possible native host trees are Beccariopsis madagascariensis , itself a critically endangered species ( DRANSFIELD & BEENTJE 1995), and Dypsis fibrosa , which is more widespread and not threatened. Nevertheless, E. epiphytica has not, to date, been found growing on either palm. When the 2000 IUCN Red List criteria (HILTON- TAYLOR 2000) are applied, the evidence suggests strongly that Eulophia epiphytica is critically endangered in the wild.

Seedlings have been raised for the joint Parc Tsimbazaza/RBG Kew Madagascan Endangered Orchid Project. The survival of the seedlings sent back to Madagascar is unknown but a number of plants grown from seed survive in Kew’s living orchid collection.