TAXONOMY 
297 
Zygophyllacece or Caltrop Family. — Herbs, shrubs or trees ( Guia - 
cum ) having jointed, often divaricate branches. Leaves usually 
opposite, stipulate and compound. Flowers regular or irregular, 
pentamerous, white, yellow, red or blue (G. officinale). Fruit a 
capsule. 
Official drug 
Guaiacum 
Guaiaci Lignum 
N. F. 
Part used Botanical origin Habitat 
_. . . . [ Guaiacum officinale f Tropical and sub- 
Resin of wood 1 , , . , . 
[ Guaiacum sanctum l tropical America 
Heart wood G. officinale and G. Tropical and sub- 
sanctum tropical America 
Fig. 163 . — Citrus Auranlium — Branch. (Sayre.) 
Rutacece or Rue Family. — Herbs ( Ruta , Diosma, Barosma ) or 
shrubs ( Xanthoxylum ) or trees {Citrus). Stems upright, often wiry 
xerophytic, in sub-family Rutece, elongated and spiny in sub-family 
