IXIACEAE. 87 



Pass; Crystal Park; Veta Mountain; Stove Prairie; river-flats near Ft. 

 Collins; Ruxton ranch; Hematite; Cherry Creek; Andrew's ranch. 



Order i8. ORCHIDALES. 

 Family 34. ORCHIDACEAE Lindl. Orchid Family. 



I. Fertile stamens 2 ; lip a large inflated sack. i. Cypripedium. 



II. Fertile stamen 1. 



A. PoUinia caudate at the base, attached to a viscid disk or gland. 

 Gland surrounded by a thin membrane ; lip toothed at the apex. 



2. COELOGLOSSUM. 



Gland naked ; lip entire. 



Sepals 3-5 nerved ; plants witli rootstocks or fibrous-fleshy roots. 

 Stem scapiform, i -leaved at the base ; anther sacks divergent. 



3. Lysiella. 

 Stem leafy ; anther-cells parallel or nearly so. 4. Limnorchis. 



Sepals i-nerved; plants with rounded or oblong, undivided corms. 



5. PiPERIA. 



B. PoUinia not produced into caudicles. 



1. PoUinia granulose or powdery. 



Anthers operculate. 6. Epipactis. 



Anthers not operculate. 



Leaves green throughout, borne on the stem. 



Leaves alternate ; spike mostly twisted. 7. Ibidium. 



Leaves 2, opposite ; spike not twisted. 8. Ophrys. 



Leaves white-reticulate, basal. 9. Peramium. 



2. PoUinia waxy or smooth. 



Plants with corms (solid bulbs) ; rarely if ever with corralloid roots ; leaves 

 solitary, not scale-like. 

 Leaf cauline ; lip not sackate ; flowers small, racemose. 



10. Achroanthes. 

 Leaf basal; lip saccate; flowers large, solitary. 11. Cytherea. 



Plants with coralloid roots ; leaves numerous, reduced to scales. 



12. Corallorrhiza. 



I. CYPRIPEDIUM L. Ladies' Slipper. 



Leaves alternate ; flowers solitary, terminal, or also in the axils of the upper 

 leaves. 



Lip 2-2.5 cm.; rarely 3 cm. long. 1. C. parviAorum. 



Lip 3.5-4 cm. long. 2. C. pubescens. 



Leaves 2, opposite or nearly so ; flowers usually several, in a contracted bracted 



raceme. 3. C. fasciculatum. 



1. Cypripedium parviflorum Salisb. In woods from Newf. to B. C, Ga. 

 and Colo. — La Veta; Piedra. 



2. Cypripedium pubescens Willd. In rich wood from N. S. to Minn., Ga. 

 and Nebr. — Stove Prairie Hill. 



3. Cypripedium fasciculatum Kell. In rich soil from Wash, to Calif, and 

 Colo. — Estes Park. 



2. COELOGLOSSUM Hartm. Long-bracted Orchis. 



I. Coeloglossum bracteatum (Willd.) Pari. In boggy woods from N. B. 

 to Alaska, N. C. and Colo. — Exact locality not given. 



