188 NYMPHAEACEAE ( WATER LILY FAMILY) 



Flowers axillary, solitary or cymose 3. P. depressa. 



Flowers in terminal dichotomous cymes. 



Stems erect 4. P. Jamesii. 



Stems prostrate-spreading . . . . . . . . . 5. P. diffusa. 



1. Paronychia pulvinata Gray, Proc. Acad. Phila. 58. 1863. Matted- 

 caespitose from a woody root, forming dense cushion-like tufts: stipules 

 broadly ovate, entire, pointless; leaves thick, oblong, obtuse, equaling the 

 stipules, and with them densely covering the short stems: flowers immersed 

 among the leaves: sepals oval, awned a little below the apex. Alpine; Col- 

 orado, Utah, and Wyoming. 



2. Paronychia sessilifolia Nutt. Gen. 1: 160. 1818. Very densely caespitose 

 from a woody root, much branched and crowded, branches very dense: 

 stipules 2-cleft; leaves imbricated, linear-subulate, the lowest erect, obtuse, 

 the upper longer, recurved-spreading, acute or mucronate, longer than the 

 stipules: sepals oblong-linear, with divergent awns rather shorter. Colorado 

 and northward to the headwaters of the Missouri and the Saskatchewan. 



2a. Paronychia sessilifolia brevicuspis A. Nels. Bull. Torr. Bot. Club. 

 26: 237. 1899. More densely tufted: the lower leaves obtuse: flowers sub- 

 cymose: calyx with a swollen turbinate base; sepals closely valvate, forming 

 a short cylindrical tube closed at the summit by their short arched tips, the 

 awn very short. Open stony ridges; southern Wyoming. 



3., Paronychia depressa (Nutt.) A. Nels. Bull. Torr. Bot. Club 26: 236. 

 1900. Spreading in a close mat from the crown of a woody root; silvery 

 throughout by reason of the large scarious stipules and the short silvery sca- 

 brous pubescence: leaves linear, cuspidate or bristle-pointed, scarcely longer 

 than the stipules: flowers single in the axils or in small cymes, subsessile and 

 surpassed by the subtending bracts and leaves: sepals with a cone-shaped 

 awned tip half as long as the body: filaments very short, exceeded by the slen- 

 der staminodia. Rare; dry hills near the Platte, in Wyoming. 



4. Paronychia Jamesii T. & G. Fl. N. A. 1: 170. 1838. Very minutely 

 scabrous-pubescent, caespitose and freely branched from the base: stems 

 7-15 cm. high, erect or nearly so, more or less dichotomously branched above: 

 leaves longer, linear-subulate, obtuse, about the length of the internodes: 

 cymes few-flowered, with a central subsessile flower in each division: sepals 

 linear-oblong, with very short cusps. (P. Wardii Rydb. in Small. Fl. 400. 

 19D3.) Colorado. 



5. Paronychia diffusa A. Nels. Bull. Torr. Bot. Club 26: 237. 1900. Al- 

 lied to the preceding but wholly prostrate-spreading: leaves generally longer 

 than the internodes, acute and mucronate: stipules lanceolate, silvery, shorter 

 than the internodes: cymes small, congested at the ends of the brittle branches: 

 calyx with minutely hirsute turbinate base; its cusps short and arched within: 

 filaments exceeded by the staminodia. Barren slopes and ridges, frequent; 

 Wyoming and Colorado. 



43. NYMPHAEACEAE DC. WATER LILY FAMILY 



Aquatic herbs, with horizontal trunk-like rootstocks or sometimes tubers. 

 The leaves (in ours) deeply cordate. Flowers with all the parts distinct and 

 free, solitary and axillary on long peduncles. Stamens numerous. Carpels 

 several or many, united into a compound pistil. 



1. NYMPHAEA L. YELLOW POND LILY. SPATTERDOCK 



In shallow water, sending up large leathery leaves which are usually up- 

 right but sometimes floating. Sepals 5-12, persistent, usually yellow within 

 and partly green without. Petals and stamens short and numerous, densely 

 crowded around the ovary. Ovary 8-20-celled, crowned by a radiate stigma, 

 the cells many-seeded. Nuphar. .' 



