ILLECEBRACS^S. 303 



* # Wings membranous, orbicular, wholly 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 lilies broad : 

 fruit orbicular with 3 thiii wings, emarginate above and below, the body 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. Cydoptera, Gray. Stouter : flowers large and showy, 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. ILI^ECEBRACE^E. 



An order related to both CaryopTiyllacece and Amarantacea, but placed 

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

 ous-stipulate Caryophyllaceo? 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. Stamens 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-cIe/l : 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 in crowded dichotomous cymes. 



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

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

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

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

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



