THE SPERMATOPHYTA 



361 



ncttod venation in tho leaf as opposed to the typically 

 parallel-veined system of the monocotyledonous leaf; (2) the 

 distribution of the vascular system in a ring or tube separat- 

 ing an internal pith from an external cortex, as opposed to 

 the irregularly scattered system of separate bundles in the 

 monocotyledonous stem; and (3) the development of the floral 



Fig. 231. 



Fig. 231. — Characteristics of a typical dicotyledonous plant. .1, loaf, 

 netted-veined. B, .stem, showing ring of wood and bast. C and D, the flower, 

 showing the floral parts in fives. E, section of seed, showing dicotyledonous 

 embryo. (From Gager's "Fundamentals of Botany", P. Blakiston's Son and Co., 

 Philadelphia). 



Fig. 232. — Characteristics of a typical monocotyledonous plant. A, leaf, 

 parallel-veined. B, stem, showing fibro-vascular bundles irregularly scattered. 

 C and D, the flower, showing the floral parts in multiples of three. E, section of 

 seed, showing monocotyledonous embryo. (From Gager's "Fundamentals of 

 Botany", P. Blakiston's Son and Co., Philadelphia). 



parts in multiples of four or five as opposed to the construction of 

 the monocotyledonous flower, which is typically on the plan of 

 three. 



The dicotyleilons, which include over 100,000 species, are 

 generally divitled into two main groups; the more primitive 

 Archirhldvnjdeae, in which the calyx and corolla ni-e either vei'v 



