DEVELOPMENT OF PLANTS 



395 



132. Arales, the Aroid Order. — These plants are largely tropi- 

 cal and are characterized by large and generally net-veined leaves 

 and showy inflorescences and fruit (Fig. 286). They present 

 an odd series of striking forms quite different from other mono- 

 cotyledons. Many of them are familiar plants owing to their 



Fig. 286. Inflorescence of the Arales: A, habit of the jack-in-the-pulpit. 

 B, diagram of the inflorescence with spathe, s, opened on one side to show 

 the spadix, sp, bearing staminate flowers at the base. C, a pistillate flower 

 consisting of a single naked carpel. D, a staminate flower of four two-lobed 

 anthers. E, section of the inflorescence of one of the arums — p, compart- 

 ment containing pistillate flowers; s, staminate flowers. 



extensive cultivation in green-houses, as the calla lily (Richardia), 

 Caladium, often with variegated leaves, and the gigantic leaves of 

 Dracontmm and Colocasia, known as the elephant ear, and the 



