Tetramicra canaliculata (Aubl.) Urb.

Authority

Ackerman, James D. 1995. An orchid flora of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 73: 1-203.

Family

Orchidaceae

Scientific Name

Tetramicra canaliculata (Aubl.) Urb.

Description

Species Description - Plants glabrous epiphytes or terrestrials. Roots produced from base of erect stems, gray and 1-2 mm diam. when aerial, white and 2-4 mm diam. when subterranean. Rhizomes elongate, commonly above the soil surface on stilts of aerial roots. Stems slightly thickened, 4-25 mm long. Leaves several, thick, stiff, narrowly subcylindric, 1-21 cm long. Inflorescences slender, erect; scape bracteate; racemes laxly few-flowered, rarely paniculate; floral bracts thin, ovate, 2-3 mm long. Flowers showy, resupinate. Pedicellate ovary filiform, 12-18 mm long. Sepals and petals greenish brown, sometimes spotted, spreading. Sepals oblonglanceolate to elliptic-obovate, acute, 7-11 mm long, 2-5 mm wide, the lateral sepals slightly larger than the dorsal. Petals elliptic to oblanceolate, acute to obtuse, 6-9 mm long, 1-3 mm wide. Lip rose-colored, prominently trilobed, 11-15 mm long; lateral lobes sometimes with dark veins, broadly elliptic, rounded, 6-8 mm long, 4-7 mm wide; midlobe with dark veins and yellowish at the middle, obovate, 8-12 mm long, 4-9 mm wide. Column stout, apically expanded and conspicuously winged, c. 6 mm long; pollinia of 4 very unequal-sized pairs. Fruits ellipsoidal, ca. 15 mm long.

Discussion

1. Tetramicra canaliculata (Aublet) Urban, Repert. Spec. Nov. Regni Veg. 15: 306. 1918. Limodorum canaliculatum Aublet, Hist. PL Guiane 2: 821. 1775. Type. Plumier s.n., from Haiti (original illustration at P, not seen; reproduction: Plumier, PL Amer. t. 181, f. 1. 1758). Fig. 86. Cymbidium rigidum Willdenow, Sp. PL, ed. 4, 106. 1805. Tetramicra rigida (Willdenow) Lindley, Gen. Sp. Orchid. PL 119. 1831. Type. Plumier illustration mPl. Amer. t. 181. 1758. Cyrtopodium elegans Hamilton, Prodr. PL Ind. Occid. 53. 1825. Tetramicra elegans (Hamilton) Cogniaux in Urban, Symb. Ant. 6: 548. 1910. Type. Hamilton s.n., from Green Castle, Antigua (P, not seen). Epidendrum subaequale Eggers, Fl. St. Croix 113. 1879. Syntypes. Eggers 333, from St. Thomas (NY, photograph seen); Eggers 837, from St. Thomas (LE, photograph seen). Phenology & Pollination. Flowering occurs from January to June. Plants in sunny, exposed sites flower more frequently than do plants in shady sites. The nectarless flowers are partially self-incompatible because hand self-pollinations yield 10-14% fruit set. Cross-pollinations are 8 0 % successful. At one population in Susua, natural fruit set was only 6%, mostly because of the rarity of pollinator visits (Pagan, Martinez, & Ackerman, unpub.) Taxonomic Notes. Dod (1983) suggested that the Tetramicra of Hispaniola are different from those of Puerto Rico and the Virgin Islands. If the different island populations represented separate species, then T. canaliculata would be endemic to Hispaniola and T. elegans would represent our plants. The latter (sensu Dod) differs by having a yellow stigma, yellow groove on the lip, and mostly terete leaves. When the two are grown in a common garden, T. elegans always flowers later than T. canaliculata. Unfortunately, dried specimens do not clearly show these differences. A field-oriented study is needed to clarify relationships in the group.

Distribution

General Distribution. Florida (U.S.A.), Hispaniola, the Lesser Antilles, Puerto Rico, and the Virgin Islands.

United States of America North America| Haiti South America| Dominican Republic South America| West Indies| Puerto Rico South America| Virgin Islands South America|