216 Key to the System of 



United upper lobes of the calyx much longer than the 

 lower. 



Slightly spinescent ; branchlets rather elongated ; leaves 

 quite small, from almost cordate to ovate, oblique; flowers 

 on long stalklets ; bracteoles connate ; fruit elongate- 

 elliptical, almost without any stalk-like base. 



B. buxifolia. 



1015. Branchlets leafy ... 1016 



Branchlets leafless ... ... ... ... ... 1019 



1016. Leaves from orbicular to almost renate. 



Tall ; branchlets robust ; leaves very small, rigid, alter- 

 nating, but crowded, convex, at the margin recurved ; 

 flowers on short stalklets ; fruit roundish, much com- 

 pressed, almost without any stalk-like base, densely 

 invested with short brown hairlets. B. foliosa. 



Leaves from linear-lanceolar to cordate or from 

 elliptic to obovate or obcordate ... ... ... 1017 



1017. Leaves from obcordate to obovate. 



Rather tall, much spinescent ; leaves quite small, rigid ; 

 flowers on short stalklets ; fruit small, glabrous, some- 

 what elliptical, with a stalk-like base. 



B. microphylla. 



Leaves from linear-lanceolar to ovate or almost 

 cordate ... 1018 



1018. Branchlets nearly cylindrical. 



From rather dwarf to tall ; leaves from cordate- to linear- 

 lanceolar, much pointed, at the margin recurved ; flowers 

 on rather conspicuous stalklets ; fruit lanceolar-elliptical, 

 with a short stalk-like base. B. cinerea. 



Branchlets much compressed. 



Rather dwarf ; leaves usually distant and few, always 

 alternating, the lower generally ovate, the upper narrower, 

 but often longer; flowers on short stalklets; fruit elongate- 

 elliptical, with a long stalk-like base, at the margin 

 thickened. B. heteropliylla. 



