ILLECEBRACE.E. 303 



* # Wings membranous, orbicular, wkclly encircling the fruit, strongly net -veined. 



2. A. micrantha, Torr. Prostrate : peduncles shorter than the petioles : 

 flowers small and inconspicuous, reddish green, the limb scarcely 2 Hues broad: 

 fruit orbicular with 3 thin wings, emarginate above and below, the bod// rather 

 broad and with a light spongy exterior. — On the plains from the Saskatchewan 

 to the Arkansas and S. W. Colorado. Often confounded with the next, which 

 is of more southern range. 



3. A. cycloptera, Gray. Stouter : flowers large and show;/, upon elongated 

 peduncles : fruit with firmer and more prominently veined wing, emarginate at 

 neither end, the firm smooth narrow body usually 3-nerved between the wings.— 

 S. Colorado to New Mexico and W. Texas. 



Order 63. ILL,ECEBR4CE;E. 



An order related to both Caryophyllacea? and Amarantacece, but placed 

 by Beuthara and Hooker with the latter. Distinguished from the scari- 

 ous-stipulate Caryophyllacece by the solitary or sometimes geminate 

 ovules, undivided or 2-cleft style, and one-seeded utricular or akene-like 

 fruit: the petals wholly wanting or reduced to mere filaments; these 

 and the stamens usually more perigynous. 



1. PARONYCHIA, Tourn. Whitlow-wort. 



Sepals 5, linear or oblong concave, awned at the apex. Stamen3 5. — 

 Tufted herbs, with dry and silvery stipules. 



* Flowers terminal, solitary and sessile. 



1. P. pulvinata, Gray. Matted-cespitose from a woody root, forming 

 dense cushion-like tufts : stipules broadly ovate, entire, pointless : leaves thick, 

 oblong, obtuse, equalling the stipules, and with them densely covering the short 

 stems : flowers immersed among the leaves : sepals oval, awned a little below 

 the apex. — Proc. Phil. Acad. 1863, 58. Alpine. Uinta Mountains, Rocky 

 Mountains of Colorado, and southward. 



2. P. sessiliflora, Nutt. Very densely cespitose 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. 



* * Flowers m crowded dichotomous cymes. 



3. P. Jamesii, Torr. & Gray. Very minutely scabrous-pubescent, cespi- 

 «ose, much branched from the base : stipules ovate-lanceolate, acuminate or 

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

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

 sepals linear-oblong, with very short cusps. — Fl. i. 170. Colorado. 



