312 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



1. Achyronychia cooperi A. Gray, Amer. Acad. Arts and Sci. Proc. 



7:331. 1868. 



Mohave and Yuma Counties, 2,000 feet or lower, March and April. 

 Western Arizona, southern California, and Baja California. 



An attractive little plant, forming mats on the desert sand, with 

 bright green foliage and snow-white flowers. 



9. PARONYCHIA. Nailwort 



Plant perennial, with an almost woody caudex, pulvinate-cespitose ; 

 herbage scabrous-puberulent; flowering stems short; leaves crowded, 

 the blades linear, thickish, cuspidate, the stipules conspicuous, white, 

 sharply acuminate; calyx lobes hooded toward the apex, cuspidate; 

 petals none. 



1. Paronychia depressa Nutt. ex Torr. and Gray, Fl. North Amer. 

 1:171. 1838 (as synonym). 



Paronychia jamesii Torr. and Gray var. depressa Torr. and 

 Gray, ibid. 



Crater Mound, Coconino County, about 5,500 feet (Eastwood and 

 Howell 6918). Nebraska to Texas and northern Arizona. 

 In the collection cited the styles are completely united. 



10. HERNIARIA. Burstwort 



Plant annual, small and inconspicuous, hispidulous; stems erect or 

 ascending, branching from the base; flowers minute, greenish, in 

 dense axillary clusters: perianth-segments in one series; fruit 1 -seeded, 

 indehiscent. 



1. Herniaria cinerea DC. and Lam., Fl. Frang. Sup. 375. 1815. 



Sentinel, Maricopa County (Orcutt 117), near Casa Grande, Pinal 

 County (Harrison 7518), March. Southern Arizona and California; 

 introduced from southern Europe. 



11. SILENE. Catchfly, campion 



Plants herbaceous, annual or perennial; herbage often viscid; 

 flowers in racemes, cymes, cymose panicles, or solitary; calyx gamo- 

 phyllous, campanulate or cylindric, more or less inflated, longitudi- 

 nally nerved; petals 5, often deeply notched, with scalelike or fringed 

 appendages; stamens 10; capsule dehiscent by apical teeth. 



Key to the species 



1. Stems very short, densely cespitose in cushionlike mats; herbage glabrous or 

 puberulent, not glandular; leaves crowded, narrowly linear; flowers about 



1 cm. long; petals normally purplish pink 1. S. acaulis. 



1. Stems elongate, leafy, not or very loosely cespitose; leaves not crowded (2). 

 2. Plants annual ; petals entire to shallowly cleft (3) . 



3. Herbage puberulent, hirtellous, or glabrate; upper internodes with a 

 sharply defined viscid area; leaves acute, mostly linear to oblong- 

 lanceolate, the lowest oblanceolate; inflorescence cymose-paniculate; 



capsules oblong-ovoid 2. S. antirrhina. 



3. Herbage villous; internodes not viscid; leaves very obtuse, apiculate, all 

 broadly spatulate; inflorescence racemose; capsules broadly ovoid. 



3. S. ANGLICA. 



