386 Key to the System of 



Corolla white or green or blue or lilac-colored ... 1689 



1689. Corolla greenish ... 1690 



Corolla white or bluish or lilac-colored ... 1691 



1690. Corolla streakless. 



Desert-plant, never tall, beset with short but rigid hairlets ; 

 leaves very small, from rhomboid- to elliptic-ovate, some- 

 what recurved at the margin ; flowers axillary, on 

 conspicuous stalklets ; calyx rather elongated, open when 

 fruit-bearing ; upper division of the corolla longer than 

 the lower ; anther-appendages shorter than the cells. 



F. chlorantha. 

 Corolla violet-streaked. 



Rather tall, partially beset with short hairlets ; leaves 

 rather small, from rhomboid- to elliptic-oval, entire or 

 scantily denticulated, recurved at the margin ; flowers 

 quite large, singly axillary, on conspicuous stalklets ; 

 upper division of the corolla somewhat longer than the 

 lower ; lateral lower lobes semilanceolar, pointed ; anther- 

 appendages shorter than the cells. F; Walter!. 



1691. Corolla upwards blue- or lilac-colored ... ... 1692 



Corolla nearly or quite white ... ... 1699 



1692. Thorny. 



Never tall, branchlets acicular-spinescent ; leaves quite 

 small, from orbicular- to lanceolar-ovate, almost entire 

 and glabrous ; flowers all singly axillary, on conspicuous 

 stalklets ; corolla spotted towards its orifice with brownish- 

 yellow dots, upwards lilac-colored ; one of the anther- 

 appendages much longer than the cells. Figure 107. 



F. spinosa. 



Thornless 1693 



1693. Leaves comparatively long. 



Tall ; leaves rather large, flat, flaccid, mostly rhomboid- 

 ovate, remotely indented, almost glabrous ; flowers in 

 terminal racemes or some axillary ; lobes of the calyx of 

 about equal length ; corolla lilac- or somewhat violet- 

 colored ; anther-appendages hardly longer than the cells. 



F. melissifolia. 



Leaves comparatively short ... ... ... ... 1694 



