xviii KEY TO FAMILIES AND ABNORMAL GENERA 



Flowers in a thick spike enclosed in a spathe : leaves large 

 radical • . /. 424* arace^. 



Flowers in slender spikes : climbers with alternate three- 

 nerved leaves or epiphytes with leaves in fours . . , 



/. 342. PIPERACEiE. 



64 -{ Flower consisting of two or more stamens and an ovary 



I only in the axil of a small bract, arranged in spikes. 



Trees with alternate, stipulate, toothed leaves (Willow) 



/. 377. SALIX. 



Flowers aggregated in flat or hollow, fleshy involucres . . 



/. 366. URTICACE/^i. 



Sepals three, petals three, stamens usually three or six. 



Stamens and style united into one column : one petal 

 (usually the front one) larger often spurred or saccate : 

 seeds minute. Perennial herbs, on the ground or on 



trees A 379- orchidace^e. 



65 \ Anthers five, connected round the stigma, but free of it : 

 hind petal hooded, two front petals bifid : front sepal 

 spurred or saccate. Herbs, all on the ground .... 



p. 59. BALSAMINEiE. 



Other herbs, shrubs and trees 62 



