316 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



3. CYTHEREA Salisb. 



1. Cytherea bulbosa (L.) House. Calypso. Occasional at low altitudes in moist 

 woods. Alaska to Calif., N. Mex., Mich., Me., and Lab. {Calypso bulbosa Oakes.) — 

 Plants glabrous, the stem naked, 5 to 15 cm. high, from a bulblike base; leaf 1, rounded, 

 2 to 5 cm. long; flowers variegated, the sepals and petals 10 to 15 mm. long, magenta, 

 the lip 15 to 20 mm. long, yellow-hairy within. 



Sometimes known as Venus'-slipper. The plants flower early in the season. 



4. SERAPIAS L. 



1. Serapias gigantea (Dougl.) A. A. Eaton. Helleborine. Collected by Vreeland 

 in meadow near Lake McDonald. B. C. to Calif., Tex., and Mont. {Epipactis gigantea 

 Dougl.) — Stem very leafy, from a rootstock, 30 to 70 cm. high, nearly glabrous; leaves 

 ovate to narrowly lanceolate, 5 to 15 cm. long, with numerous conspicuous parallel 

 veins; flowers 3 to 10, in a leafy raceme, greenish, with purple veins; lip 1.5 to 1.8 

 cm. long, not spurred; capsule 1.5 cm. long. 



5. PERAMIUM Salisb. 



1. Peramium decipiens (Hook.) Piper. Rattlesnake-plantain. Frequent at 

 low and middle altitudes, in deep woods. Alaska to Calif., N. Mex., N. H., and Que. — 

 Stems 20 to 40 cm. high, covered above with fine glandular hairs; leaves mostly at the 

 base of the stem, forming a rosette or sometimes erect, lance-ovate, 4 to 6 cm. long, 

 sharp-pointed, blotched \\ith pale green; flowers 7 to 9 mm. long, greenish white, 

 in a one-sided spike. 



The dead stems often persist for one or two years. 



6. IBIDIUM Salisb. 



1. Ibidium romanzoffianum (Chana.) House. Lady's-tresses. Plate 47, B. 

 Occasional on the east slope at low altitudes, in wet thickets; in sphagnum bogs on the 

 west slope. Alaska to Calif., N. Mex., Pa., and Newf. (/. stridum House; Spiranthes 

 romanzoffiana Cham.) — Plants stout, glabrous, 15 to 30 cm. high, from fleshy roots, the 

 stems leafy; leaves linear, 5 to 15 cm. long; flowers 6 to 8 mm. long, in dense 3-angled 

 spikes, white, sweet-scented; lip not spurred. 



7. HABENARIA Willd. Bog-orchis. 



Plants glabrous, with 1 to many leaves, the roots fleshy; flowers green or white, in 

 racemes. 

 Leaves 1 or 2, at the base of the stem. 



Leaf 1; spur about as long as the lip 1. H. obtusata. 



Leaves 2; spur twice as long as the lip or longer 2. H. orbiculata. 



Leaves several or numerous, always more than 2. 



Lip 3-toothed at the apex 3. H. bracteata. 



Lip entire. 

 Leaves all at or near the base of the stem, usually withering before the opening 



of the flowers 4. H. unalaschensis. 



Leaves scattered along the stem, remaining green. 



Flowers white; lip broadened at the base 5. H. dilatata. 



Flowers green; lip linear. 



Spur sacklike, much shorter than the lip 6. H. stricta. 



Spur slender, nearly as long as the lip 7. H. sparsiflora. 



1. Habenaria obtusata (Pursh) Richards. One-leaf bog-orchis. Found only on 

 mossy banks in wet woods along S'wiftcurrent Creek just below Lake McDermott. 

 Alaska to Colo., N. Y., and Newf. (Lysiella obtusata Rydb.) — Stems 10 to 20 cm. high, 

 slender; leaf obovate, 5 to 10 cm. long, obtuse; spike loosely flowered, 2 to 5 cm. long, 



