202 Key to the System of 



OXYX.OBXUBX. 



959. Leaves indented or incised. 



Erect, shrubby; leaves opposite, from deltoid-ovate to 

 rhomboid-lanceolar, with pungent lobes or denticulations, 

 flat, generally glabrous ; racemes rather elongated ; fruit 

 ellipsoid-cylindrical, attenuated into a conspicuous stalk- 

 like base. O. trilobatum. 



Leaves entire ... ... ... ... ... ... 960 



960. Prostrate, semi-herbaceous. 



Sometimes ascendant, scarcely half -shrubby; leaves opposite 

 or in whorls of three, from ovate to lanceolar, pungent- 

 pointed, soon glabrous, almost flat; flowers few, in umbel- 

 like racemes ; calyx scantily beset with hairlets ; fruit 

 almost sessile, rather blunt. O. procumbens. 



Erect or diffuse, shrubby ... ... ... ... 961 



961. Leaves soon glabrous. 



Erect or diffuse ; leaves opposite or in whorls of three, from 

 elliptical to lanceolar, sharp -pointed, recurved at the 

 margin ; stipules conspicuous, pointed ; flowers few, in 

 umbel-like racemes; calyx beset with short hairlets; fruit 

 almost sessile, acute. O. alpestre. 



Leaves beset underneath with often appressed and 

 shining hairlets. 



Erect or seldom diffuse ; leaves in whorls of three, from oval- 

 to narrow-elliptical, recurved at the margin ; stipules 

 inconspicuous ; flowers several, in short racemes ; calyx 

 densely beset with soft hairlets outside ; fruit pointed, 

 almost sessile, glabrous. O. elliptic um. 



SPHAEROXiOBIUXK. 



962. Tube of the calyx about as long as the upper lobes. 



Never tall, always glabrous, almost leafless or the leaves 

 scanty small and narrow ; branches slender, cylindrical ; 

 flowers small, in irregular almost spike-like racemes ; 

 calyx soon dark-colored ; fruit small. S. vimiiieum. 



VXJKXNARIA. 



963. Flowers in spike-like racemes. 



Glabrous ; branchlets weak ; leaves seldom developed, but 

 when present consisting of one to three rather large leaf- 

 lets, these from oval- to elliptic-lanceolar in form; racemes 

 generally elongated ; bracts minute. V. denudata. 



