210 EVOLUTION OF PLANTS 
cee), as well as many others more or less familiar. 
(Fig. 51, C, D.) 
The order Tricocce, of somewhat doubtful affinity, in- 
cludes the single family Euphorbiacee with the various 
species of Euphorbia as types. A few are cultivated, 
like the familiar castor-bean (Ricinus), and the showy 
Fic. 51 (Higher Choripetale).— A, wall-flower (Cheiranthus): the parts 
of the flower are definite inmumber; B, the six stamens, the two outer 
ones shorter than the others, and the pistil, car, made up of two cohe- 
rent carpels; C, flower of Oxalis, the parts perfectly symmetrical, and 
in fives; D, the ten stamens, an, in two sets of five each, and the five. 
carpels, st; E, flower of a Spirza, one side removed to show the five 
free carpels, car, and the numerous stamens inserted upon the calyx 
margin; F, flower of the common pea (Pisum), showing marked zygo- 
morphy; G, the ten stamens, one of them free, and the single carpel, car, 
of the pea; H, a flower of Fuchsia, with ‘inferior’ ovary, 0, and showy 
colored sepals. 
Crotons and Poinsettia of the greenhouses. The 
flowers in all Euphorbiacez are inconspicuous, but it 
is common for them to develop showy bracts about the 
clusters of flowers, and these serve the same purpose as 
the showy petals of other Choripetale. 
The most specialized as well as the most numerous 
