56 Key to the System of 



275. Umbels simple-. ... ... ... ... 276 



Umbels compound ... ... ... ... ... 280 



276. Fruitlets dorsally compressed. 



Small perennial herbs ; leaves all basal ; umbel-stalk elon- 

 gated ; fruitlets from dorsal impression almost hollowed 

 in a direction contrary to the styles, narrowly connate ; 

 ridglets (vittae) smooth; oil-ducts absent or rudimentary. 



Huanaca. 1215 



Fruitlets laterally compressed or turgid .... ... 277 



277. Calyx usually with five terminal lobes or denticles. 



Perennial herbs, not rarely tufted; apex of petals straight; 

 fruit turgid, the fruitlets often only narrowly coherent; 

 oil-ducts of fruit present. Azorella. 1216 



Corolla usually without any conspicuous terminal lobes 

 or denticles ... ... ... ... ... ... 278 



278. Oil-ducts of fruit present. 



Perennial herbs ; leaves simply or doubly pinnatisected, 

 the segments very small and mostly incised ; fruitlets 

 broadly coherent; ridglets smooth. Oreomyrrhis. 1218 



Oil-ducts of fruit absent 279 



279. Involucral bracts few or absent. 



Annual or perennial herbs, never tall; leaves mostly 

 scattered or basal; stipules present, upwards free or quite 

 adnate; flowerstalks often abbreviated ; flowers often 

 only partially fruit-bearing; petals usually contiguous 

 before expansion, their apex straight; fruits often only 

 moderately compressed, both fruitlets alike and smooth. 



Hydrocotyle. 1219 



Involucral bracts many, towards the base connate. 



Annual or perennial herbs, not rarely tall ; leaves mostly 

 basal ; stipules absent ; flowerstalks often elongated ; 

 petals overlapping before expansion, apex of petals 

 straight ; fruit often almost flat or much compressed, 

 usually rough, narrowly and shortly coherent ; one of the 

 fruitlets not rarely undeveloped or dissimilar. 



Didiscus. 1228 



