lo General Key to the Families 



I. SiSYRINCHIUM. L. 



1. S. angustifolium. Mill. Stiif Blue-eyed Grass. 



2. S. idahoense. Bicknell. Twisted Blue-eyed Grass. 



3. S. septentrionale. Bicknell. Small Blue-eyed Grass. 



4. S. calif ornicum. Yellow Blue-eyed Grass. 



ORDER X. ORCHIDALES 



XVIII. ORCHIDACE^. ORCHIS FAMILY 



Perennial herbs, often with corms or tuberoid roots, sometimes 

 rootless saprophytes; leaves paralleled-nerved, solitary or several, 

 alternate; flowers solitary, in racemes or spikes, perfect, zygo- 

 morphic, gynandrous with the perianth adnate to the one-celled 

 ovary, one division termed the lip differing from the rest in shape, 

 and sometimes prolonged into a spur at the base; fruit a one- 

 celled, three-valved capsule. 



TRIBE CYPRIPEDIE^ 



I. Cypripedium. L. 



1. C. pubescens. (Willd.) Knight. Large Yellow 



Lady's Slipper. 



2. C. parviflorum. Salisb. Small Yellow Lady's Slip- 



per. 



3. C. passerinum. Richards. White Moccasin Flower. 



TRIBE OPHRYDIE.E 



II. Orchis. (Tourn.) L. 



I. O. rotundifolia. Banks. Fly-spotted Orchis. 

 III. Habenaria. Willd. 



1. H. dilatata. (Pursh.) Gray. White Rein Orchis. 



2. H. bracteata. (Willd.) R. Br. Long-bract ed Rein 



Orchis. 



3. H. obtusata. (Pursh.) Richards. Northern Rein 



Orchis. 



4. H. hyperborea. (L.) R. Br. Leafy Rein Orchis. 



5. H. gracilis. 'Wats. Graceful Rein Orchis. 



6. H. orbiculata. (Pursh.) Torr. Round-leaved Rein 



Orchis. 



