Rhipidorchis micrantha

Native Fan Orchid

Rhipidorchis micrantha (A.Rich.) D.L.Jones & M.A.Clem., Orchadian 14(8): Suppl. xv (2004).

Oberonia micrantha A.Rich., Voy. Astrol., Bot. t. 3 (1833) 7 (1834); Eria richardiana Rchb.f. in Seem., Fl. Vitiensis 300 (1868); Phreatia richardiana (Rchb.f.) Kraenzl. in Engler, Pflanzenr. Orch.-Mon. 50: 26 (1911); Phreatia micrantha (A.Rich.) Schltr., Repert. Spec. Nov. Regni Veg. Beih. 1: 919 (1913); Rhynchophreatia micrantha (A.Rich.) N.Hallé, Fl. Nouve.-Caledon. Depend. 8: 341 (1977). Type: Vanikoo, echantillon perdu, A. Richard s.n. (holo P, iso W; icon P).

Thelasis samoensis Kraenzl., Bot. Jahrb. Syst. 25: 607-8 (1898); Phreatia samoensis (Kraenzl.) Schltr., Mem. Herb. Boissier 21: 75 (1900). Type: Upolu: Lapua, May 1895, [Anon] 652 (syn ?); Westlichdavon, [Anon] 606 (syn?).

Phreatia macrophylla Schltr., Bot. Jahrb. Syst. 39: 78 (1908). Type: New Caledonia, Nord-Bezirk: auf Baumen in den Walden der Berges bei Oubatche, Dec. 1902, R. Schlechter 15465 (holo B; iso BM, P, PR, S).

Phreatia macrophylloides Kraenzl. in Vieteljahrsschr. Nat. Ges. Zurich 74: 93 (1929). Type: Ins Loyauts, lufon, 26 Nov. 1925, A.Ü. Däniker 2483 (holo Z; iso Z).

Phreatia robusta R.S.Rogers, Trans. & Proc. Roy. Soc. South Australia 54: 39-40 (1930). Type: cult. Brisbane, Jan. 1930, C.T.White ex Queensland; Near Cairns, Jan. 1930, A. Beck s.n. (holo AD).

Distribution

Occurs in north-eastern Queensland from Iron Range to Tully River.

Altitude: 0-400 m.

Also occurs in Indonesia, New Caledonia, New Guinea, the Solomon Islands and Vanuatu.

Description

Epiphytic or lithophytic herb with single, fan-like growth that enlarges each year. Leaves 4-10, crowded, erect to prostrate, distichous, alternate, in fan-like array, sessile, bases sheathing stem, closely imbricate; lamina articulate on apex of leaf base, linear, 10-35 cm x 2-2.5 cm, dark green, thin-textured, conduplicate in lower third, apex unequally emarginate. Inflorescence an axillary raceme, erect to arching, 200-450 mm long, thin, wiry; base sheathed by conduplicate leaf base; pedicels 2.5 mm long, including ovary. Flowers numerous, resupinate, porrect, cupped, 2-2.5 mm x 2-2.5 mm, white. Sepals and petal spreading, ovate, apices acute. Dorsal sepal porrect, 1.5 mm x 1 mm. Lateral sepals free, divergent, 1.5 mm x 1.5 mm, bases fused to column foot. Petals incurved, 1 mm x 0.7 mm. Labellum unlobed, 1.2 mm x 1.2 mm, decurved near the middle, with shallow basal depression containing sticky liquid. Column 1 mm long. Column foot short, slightly curved. Capsules porrect, dehiscent.

Ecology

Occurs in rainforests and coastal ranges at moderate altitudes, where it grows in humid airy positions on trees, and less often rocks. It is commonly found growing on mossy branches overhanging streams.

Locally common.

Flowering period: October-February.

Name Changes

Until recently known as Rhynchophreatia micrantha.