370 
PHARMACEUTICAL BOTANY 
Official drug Pait used Botanical origin Habitat 
Helianthemum Herb ‘ Helianthemum Eastern United 
N.F. canadense States 
XX. Order Opuntiales .—Cactacea or Cactus Family. —Herba¬ 
ceous rarely arborescent ( Cereus giganteus ) more or less succulent 
Fig. 218 .—Daphne mezereum —Fruiting branch and flowers. (Sayre.) 
plants living in warm, dry ( Peireskia) y usually desert situations, 
rarely becoming epiphytic and correspondingly modified. Stems 
accordingly varying from elongate, slightly enlarged, green (. Peireskia ) 
to flattened ( Cereus and Opuntia), to condensed (Echinocactus , 
