CELASTRACEiE — RHAMNACE/E 



145 



protandrous, with exposed honey. They are tricecious. 

 The staminate flowers contain a rudiment of the pistil, 

 and the pistillate rudimentary stamens. According to 

 Darwin's experience, the apparently hermaphrodite 

 flowers are, as a rule, functionally male, and in com- 

 paratively few cases produce seed.^ The flowers are 



Fig. 85. — Transverse section of seed of 

 Jiuonymus. x 8. 



Fig. 86. — Longitudinal section of seed of 

 Euonyvius. x 8. 



principally visited by flies. The capsule, enclosing four 

 to five cells, opens in as many valves along the middle 

 of each cell. The pod is red when ripe, and when 

 opened shows the seeds enclosed in a brilliant orange 

 or red arillus. The embryo is embedded in albumen. 

 It consists of two cotyledons (Fig. 85 and Fig. 86) 

 and the radicle (Fig. 86). The cotyledons, which is 

 very unusual, are quite green. 



EHAMNACE.^ 



We have only one genus, Ehamnus, the Buckthorn, 

 with two species. R. catharticus, the Common Buck- 

 thorn, has the leaves toothed, and fruit black ; while R. 

 Frangula, the Alder Buckthorn, has the leaves entire, 



1 Forms of Flowers. 



