178 Key to the System of 



853. Fruit-calyx rather large, turgidly obovate. 



A desert-plant, almost herbaceous ; leaves from obovate to 

 rhombeous, somewhat sinuous and denticulated; staminate 

 and pistillate flowers on the same plant, all in axillary 

 clusters ; fruit-calyx minutely bilobed at the summit, 

 without any appendages. A. holocarptim. 



Fruit-calyx rather small, depressed-globular. 



A desert-plant, almost herbaceous ; leaves small, from 

 lanceolar- to rhomboid-obovate, slightly sinuous and 

 somewhat denticulated ; staminate and pistillate flowers 

 on the same plant, in axillary clusters or some solitary ; 

 fruit-calyx minutely bilobed at the summit, without any 

 appendages. A. spougiosum. 



RHACODia. 



854. Leaves mostly opposite ... ... ... ... 855 



Leaves mostly scattered ... ... ... 856 



855. Leaves acute. 



Climbing or somewhat prostrate and diffuse, weak ; leaves 

 small, from deltoid to lanceolate -linear ; panicle small; 

 fruit red or yellow outside ; seed placed horizontally. 



R. nu tans. 



Leaves obtuse. 



Leaves rather large, ovate-hastate or some verging into a 

 rhombeous form ; panicle seldom large ; fruit red outside ; 

 seed placed horizontally. B. hastata. 



856. Branchlets often ending in thorns. 



Finally rather tall, rigid ; leaves comparatively small, from 

 oval to orbicular and deltoid or hastate; panicle often small; 

 fruit red or yellow outside ; seed placed horizontally. 



R. spiuescens. 



Branchlets seldom ending in thorns. 



Finally tall, robust, erect or straggling, rarely dwarfed; 

 leaves succulent, comparatively large, from ovate- to 

 lanceolar- or hastate- or narrow- elliptical ; panicle often 

 ample; fruit usually red outside; seed placed horizontally. 



B. Billardieri. 



