ORCHIDACE^E 267 



NlGRITELLA Rich. 



Nigritella angustifolia L. Vanilla Orchid. 



Tubers palmately divided. Stem 3-8 inches high, leafy below 

 and sometimes throughout. Leaves linear, channelled, the lower 

 ones crowded. Spike conical or ovate, densely flowered. Bracts 

 as long as or longer than the perianth. Flowers small, like the bracts 

 dark carmine (N. rubra Richter) or purplerblack (N. nigra Reichb.), 

 with the odour of vanilla. Lip ovate. Apex acuminate, entire, or 

 slightly crenate. Spur very short, obovate, much shorter than 

 ovary ; remaining perianth-segments lanceolate, acuminate. 



Alpine and sub-alpine pastures, often in batches ; 5000-8500 

 feet. June to August. 



Distribution. Carpathians, Eastern, Central, and Western Alps ; 

 Cevennes, Pyrenees, Apennines, Balkans, Scandinavia. Moun- 

 tainous Europe. The red variety (N. rubra Richter) is found in the 

 Orisons and in the Maritime Alps. 



CYPRIPEDIUM L. 

 Cypripedium Calceolus L. Lady's Slipper. 



Rootstock cylindrical, knotty,, horizontal, tufted, with fleshy 

 fibres. Stem downy and leafy, 1-2 flowered, about a foot high. 

 Leaves elliptical, or ovate-lanceolate, strongly nerved, glabrous 

 above, downy beneath and at margin. Bracts similar to stem-leaves 

 but smaller. Lip yellow, saccate, large, not spurred ; the other 

 perianth-segments spreading, ij inch long, purple-brown ; the 

 upper one broadly lanceolate, acuminate, a similar one (formed of 

 the 2 lateral segments combined into one) under the lip ; the two 

 inner lateral ones linear-lanceolate, acute, usually twisted. 



Alpine and sub-alpine woods, chiefly on steep," mossy, limestone 

 slopes under the Pines or near rocks. June. 



Distribution. Carpathians, Eastern, Central, and Western Alps ; 

 Jura, Pyrenees, Caucasus, Siberia. In Europe almost to the Arctic 

 Circle. British. 



PLATANTHERA Rich. 



Root-leaves large, usually 2. Lip entire, ovary twisted, shorter 

 than the spur. Rostellum short and broad. Flowers whitish, 

 fragrant, in a lax spike. 



Platanthera bifolia Rchb. Lesser Butterfly Orchid. 



Tubers entire. Stem 12-18 inches, with 2 large broadly ovate to 

 oblong leaves at the base. Flowers yellowish or greenish white, 

 sweet-scented, rather large in a loose spike, 3-5 inches long, and 

 with lanceolate bracts about length of ovary. Two lateral sepals 

 spreading. Lip linear, entire, obtuse. Spur slender, filiform, and 

 curved, twice length of ovary. Anther-cells or pollinia usually 

 parallel. Also called Hdbenaria bifolia R.Br. 



