ORCHIDACEAE. 85 



sepals narrowly lanceolate, 2.5-3 cm. long, the spur 8-10 mm. long; petals 

 narrowly lanceolate, about 2 cm. long; lip white; capsule about 2 cm. long, 

 6-ribbed. 



Shady coppices, Great Bahama, Andros and New Providence : Florida ; Cuba 

 to Guadeloupe and Trinidad ; Colombia to Brazil. LONG-SPURRED PELEXIA. 



4. IBIDIUM Salisb. Trans. Hort. Soc. Lond. 1: 291. 1812. 



Erect terrestrial orchids, with fleshy-fibrous or tuberous roots and slender 

 stems or scapes, leaf-bearing below or at the base. Flowers small, spurless, 

 spiked, 1-3-rowed, the spikes more or less twisted. Sepals free, or more or less 

 coherent, or sometimes united with petals into a galea. Lip concave, erect, 

 embracing the column and often adherent to it, spreading and crisped, or 

 rarely lobed or toothed at the apex, bearing minute callosities at the base. 

 Column arched below, obliquely attached to the top of the ovary. Anther 

 without a lid, borne on the back of the column, erect. Stigma ovate, pro- 

 longed into an acuminate beak, at length bifid. Pollinia 2, 1 in each sac, 

 powdery. Capsule ovoid or oblong, erect. About 80 species, natives of tem- 

 perate and tropical regions. Type species: Ophrys spiralis J. E. Smith. 



Flowers white ; basal leaves linear. 1. I. tortile. 



Flowers green ; basal leaves oblong-lanceolate to elliptic. 2. 7. lucayanum. 



1. Dridium tortile (Sw.) House, Muhlenbergia 1: 129. 19*06. 



Neottia tortilis Sw. Vet. Akad. Handl. 1800: 226. 1800. 

 Spiranthes tortilis L. C. Eich. Mem. Mus. Par. 4: 59. 1818. 



Stem slender, erect, 3-6 dm. high, glabrous below, pubescent above, bear- 

 ing 2-4 bladeless acute sheaths above, and sometimes a narrowly linear leaf 

 2-7 cm. long, below the middle. Basal leaves 2 or 3, present at flowering time, 

 linear, 8-30 cm. long, 1.5-2.5 mm. wide; spike erect, 6-13 cm. long, pubescent, 

 the approximate flowers in a single spiral; flowers white; bracts ovate or ovate- 

 lanceolate, pubescent, acute or acuminate, 6-7 mm. long, about as long as the 

 ovary; sepals 5-6 mm. long, the median one elliptic, obtuse, the lateral ones 

 oblong, oblique; petals oblong, about as long as the sepals; lip 4-6 mm. long, 

 ovate-elliptic, emarginate, the callosities short; capsule about 5 mm. long. 



Savannas and borders of marshes. Great Bahama, Andros and New Provi- 

 dence : Florida ; Louisiana ; West Indies. Recorded by Mrs. Northrop as Oyro- 

 stachys peruviana Kuntze. SOUTHERN LADIES-TRESSES. 



2. Itoidium lucayanum Britton, Bull. N. Y. Bot. Gard. 5: 312. 1907. 



Spiranthes lucayana Cogn. in Urban, Symb. Ant. 6: 338. 1909. 



Boot of cylindric, fleshy tubers 2-5 cm. long, 8-10 mm. thick. Basal 

 leaves present at flowering time, oblong-lanceolate, oblanceolate to elliptic, thin 

 but somewhat fleshy, spreading, 5-nerved, reticulate-veined, at least when dry, 

 5-17 cm. long, 1-3 cm. wide, acute at the apex, narrowed at the base into a 

 rather slender petiole, which is one half to two thirds the length of the blade; 

 scape slender, including the spike 2-4 dm. high, its several leaves linear or 

 linear-lanceolate, acute or acuminate, appressed, 1-3 cm. long; spike 5-25 cm. 

 long, about 1 cm. thick, usually many-flowered; bracts lanceolate, acuminate, 

 erect, as long as the ovary or longer; flowers green, spreading; sepals linear- 

 lanceolate, acutish, 3-4.5 mm. long; petals linear a little shorter than the 

 sepals; lip ovate-oblong, obtusish, concave, 3-5 mm. long, about one third as 



