i86 THE STRUCTURE OF ECONOMIC PLANTS 



lowing the vegetative period. The axis elongates at this time to 

 produce an erect, much-branched stem which may attain a height 

 of I to 3 or more feet. It is usually somewhat glaucous, sometimes 

 sparsely pubescent with a few stiff epidermal hairs on the lower 

 portions of the stem system; and, in rare instances, is essentially 

 glabrous throughout. (Fig. 141, A.') 



Fig. 141. Development of fleshy axis of Raphanus in icicle, i, half long, 2., and globe 

 types, 3-5, showing region that becomes fleshy and origin of secondary roots; 6, abnormal 

 thickening of axis. (After Golinska, Die Gartenbauwissenschajt.') 



The Leaves. — The simple petiolate leaves are glabrous or 

 sparingly pubescent and are spirally arranged in a % phyllotaxy. 

 They are variable in shape, the smaller upper ones being more or 

 less oblong while the lower ones are deeply lyrate-pinnatifid. 



The Inflorescence and Flower. — The inflorescence is an 

 elongated raceme which is ordinarily devoid of bracts, and the 

 white or rose-lilac flowers are borne on slender pedicels. (Fig. 

 142., y4.) The pentacyclic flower is hypogynous. It consists of a 

 calyx of four sepals, a corolla with a similar number of petals, six 

 stamens in two cycles, and a pistil that has been interpreted as con- 

 sisting of four carpels by some investigators and of two by others. 

 (Fig. 143, ^.) 



The four sepals are paired. The outer median pair slightly 



