ii6 



DICOTYLEDONS 



ance with these facts we note that the catkins of the Willow 

 are erect, its flowers produce honey, and its pollen is sticky. 

 But the catkins of the Poplar hang loosely and are easily 

 shaken by the wind; the flowers produce no honey; the pollen 

 is dry ; and finally the stigma, being lobed to a greater extent 

 than in the Willow, it offers a larger surface for the reception 

 of the pollen. 



EUPHORBIACEJE (Spurge Family) 



Plants sometimes having a milky juice. Flowers usually 

 apetalous, diclinous, hypogynous. Perianth small or absent. 

 Gynsecium, syncarpous, with a lobed three- (rarely two-) 

 chambered ovary, having one-two ovules in each chamber. 

 Fruit a capsule. Seeds endospermic. 



Type : PETTY SPURGE {Euphorbia peplus). 



Vegetative characters. — An annual herb containing a white 

 milky juice and with simple leaves. Inflorescence : the stem, 

 which is simple or has two large branches, terminates in a 

 compound inflorescence, which is an umbel-like cyme of three 



Fig. 146. — Cyathium oi Euphorbia pephts. 



branches. Each of the latter is in turn a two-branched cyme 

 (dichasium), the branches of which may again be forked 

 cymes (dichasia). But throughout the whole inflorescence the 

 actual termination of each shoot is formed by a peculiar 

 inflorescence termed a Cyathium, which looks like a simple 

 flower (figs. 146, 147). — The cyathium has a cup-like in- 



