230 



BOTANY OF CROP PLANTS 



Inflorescence and Flowers.- — There are a number of 

 different types of inflorescences in the family. The flowers 

 are often single or solitary, as in the Hlies; or racemose, as in 

 the soapweed and hyacinths ; or umbellate, as in onion. The 

 umbellate or umbel-like type of inflorescence consists of many 

 flower stalks of about equal length arising near together on 

 the stem; the outside flowers open 

 first, the inside last, that is, the order 

 of opening is centripetal. This is the 

 order of opening in all racemose types 

 of inflorescences. The perianth con- 

 sists of six separate segments, in two 

 whorls of three each, which are very 

 similar in size, shape and color (Figs. 

 3 1 and 8 7) . The stamens are attached 

 to the receptacle or to the perianth. 

 The anthers are usually large and con- 

 spicuous. The superior ovary is 

 three-celled, has one style and a 

 three-lobed stigma. 

 Fruit and Seeds. — The fruit is a capsule or berry. The 

 capsule is a dry, splitting (dehiscent) fruit with several united 

 carpels. When the carpels split down the middle line as 

 they do in lilies, the dehiscence is said to be loculicidal. 

 It is distinguished from septicidal dehiscence of capsules, 

 in which the carpels open along the Hne of their union, as in 

 rhododendron, and from poricidal dehiscence in which the 

 carpels open by pores, as in the poppy. The herry is a fleshy 

 fruit possessing several to many seeds which are more or 

 less imbedded in the fleshy ovary wall (pericarp). 



The seeds always possess abundant endosperm, which en- 

 closes the embryo. Considerable quantities of oil occur in 

 the endosperm. 



Fig. 87 



Flower of onion 

 (Allium cepa). 



