344 IRIDACE.E. (IRIS FAMILY.) 



veins beneath : raceme pubescent : flowers greenish, strongly veined with 

 purple : saccate base of the lip with erect wing-like margins, strongly nerved, 

 and the nerves callous-tuberculate near the base. W. Texas and S. W. Colo- 

 rado to California and Washington Territory. 



9. CYPRIPEDIUM, L. LADY'S SLIPPER. 



Lateral sepals often united into one under the lip : sac-like lip with the in- 

 curved margin auricled near the base. Leaves large and many-nerved, 

 plaited, sheathing at the base. In ours the stem is 1 to 3-flowered, the lip is 

 slipper-shaped and mucli inflated, and the sepals and linear wavy-twisted petals 

 are brownish, pointed, and longer than the lip. 



1. C. parviflorum, Salisb. Sepals ovate or ovate-lanceolate: lip flattish 

 from above, bright yellow, fragrant : sterile stamen triangular : leaves oval, 



pointed. Colorado and eastward. 



2. C. pubescens, Willd. Stem pubescent: sepals elongated-lanceolate: 

 Up flattened laterally, very convex and gibbous above, pale yellow, scentless : 

 leaves broadly oval, acute. Colorado and eastward. 



ORDER 77. IRIDACEJE. (IRIS FAMILY.) 



Perennial herbs, with equitant sheathing 2-runked linear leaves, and 

 perfect triandrous regular flowers, the six divisions of the superior 

 perianth petal-like; stamens on the base of the sepals, with extrorse 

 anthers; ovary 3-celled, becoming a 3-lobed or triangular pod with few 

 or many seeds. Flowers showy, few or solitary. Style 3-cleft at the 

 apex. 



1. Iris. Outer segments of the flower recurved, the inner erect. Branches of the style 



petaloid, opposite the anthers. Filaments distinct. Rootstocks creeping. Seeds 

 flattened. 



2. Sisyriiichium. Segments similar, spreading. Stigmas filiform, alternate with the 



anthers. Filaments connate. Roots fibrous. Seeds globular. 



1. IBIS, Tourn. FLOWER-DE-LUCE. FLAG. 



Perianth tube prolonged above the ovary. Stamens beneath the arching, 

 petal-like branches of the style. Base of the style connate with the perianth 

 tube ; the divisions stigmatic at the thin apex, above which is a broad 2-parted 

 crest, which is decurrent on the inner side to the base of the style. Stems 

 from usually thickened rootstocks : flowers large and showy, solitary or few 

 in a forked corymb. 



1. I. Missouriensis, Nutt Stems rather slender, naked or with 1 or 



2 leaves, to 2 feet high, usually 2-flowered : leaves mostly shorter than the 

 stem : bracts dilated and scarious : flowers pale blue ; sepals and petals 2 or 



3 inches long, with narrow claws : seeds obovate, acute at base. I. Tol- 

 mieana, Herbert. I. tenax ? of Fl. Colorado. From Montana and Colorado 

 westward to the Sierra Nevada, being probably the only species of the Great 

 Basin. 



