20 KEY TO THE GENERA OF MANHATTAN PLANTS. 



Order 42. GERANIACEAE. 



123. Geranium. Capsule 5-celled , 5-valved , 5-lobed , the receptacle 

 extending up between the cells as a long 5-sided beak ; cells 1-seeded. 

 Valves dehiscing elastically upward from the base along the beak. 



Order 43. OXALIDACEAE. . 



124. Oxalis. Capsule 5-celled, (5-sided) oblong, loculicidally dehiscent. 

 Seeds few or numerous, forcibly pinched out during dehiscence, the 

 valves then collapsing. Herbs. 



Order 44. LINACEAE. 



125. Linxim. Capsule 5-carpelled, 5-celled, or 10-celled by false parti- 

 tions from the back of each carpel (10-valved from the top, false 

 partitions extending about half way to axis). Seeds flat, smooth, 

 developing mucilage on wetting. Herbs. 



Order 45. RUT ACE AE. 



126. Xanthoxylum. Carpels 3-5, raised on a short stalk. Pericarp 

 thick and fleshy (red, turning brown), 2-valved, exposing the lor 2 

 globose, shining, black, crustaceous seeds. Prickly shrub. 



Order 46. POLYGALACEAE. 



127. Polygala. Capsule 2-celled, 2-seeded, loculicidally 2-valved. 

 Seeds carunculate (caruncle 2 lobsd or 2-winged). Herbs. 



Order 47. EUPHORBIACEAE. 



Capsule (except croton monanthogynus) 3-lobed, 3-celled, 3-seeded, 

 6-valved, valves separating from the persistent centre Herbs. 



128. Croton. Capsule sessile in the calyx (stellate pubescent), 

 C. monanthogynus has the capsule 1 or 2 celled and 1 or 2 seeded. 



129. Acalypha. Capsules supported by a leaf-like involucre. Calyx 

 present. Seeds caruncled.' 



130. Tragia. Calyx present Seeds not caruncled (globose) capsule 

 bristly. 



131. Euphorbia. Capsule stalked in a cup-shaped involucre. Calyx 

 none. 



Order 48. CALLITRICHACEAE. 



132. Callitriche. Fruit solitary and sessile, or nearly so, in the axils 

 of the leaves, 4-lobed, compressed, 4-celled, separating at maturity into 4 

 indehiscent nutlets. Low marsh or aquatic herbs. 



Order 49. ANACARDIACEAE. 



133. Rhus. Fruit drupaceous, 1-seeded ; stone surrounded by thin, 

 waxy pulp. Sepals inferior (persistent). Shrubs. 



