DICOTYLEDONES— OOROLLIFLOE^ 



391 



dehiscence, or bursting tranversely at the base. Embryo large, 

 curved or coiled in a small quantity of mucilaginous albumen, 

 with foliaoeous crumpled cotyledons ; in Guscuta the embryo is 

 filiform, spiral, and the cotyledons scarcely perceptible ; radicle 

 inferior. 



Diagnosis. — G-enerally twining or trailing milky herbs, with 

 alternate exstipulate leaves ; or parasitic and leafless. Calyx 



Fig. 1159. 



Fig. 1160. 



Fig. 1162. 



Fig. 1161. 



Fig. 1163. 



Fig. 1159. Flower of Great Bindweed (ConwoZuuZiw sepium). Fig. 1160. Dia- 

 gram of the same flower, showing two bracts on the outside of the calyx. 



Fig. 1161. Vertical section of the seed of the same. -Fig.l\^2. Corolla of 



Dodder (Cuscuta) laid open to show fire epipetalous stamens and the scales 

 in its tube. Fig. 1163. Spiral embryo of a species of Cuscula. 



of 5 imbricate sepals, inferior. Corolla regular, 5-plaited or 5- 

 lobed. Stamens 5, alternate with the lobes of the corolla. 

 Ovary 2 — 4-ceIled. Fruits 2 — 4-celIed, capsular, septifragal. 

 Embryo curved, coiled, or spiral, in albumen ; radicle inferior. 



Distribution and Numbers. — They are found chiefly in the 

 plains and valleys of hot and tropical regions. A few occur in 

 temperate climates, but they are altogether absent in the coldest 



