DICOTYLEDONKS : GAMOPETAL^. 647 



the roots of the Hazel : it is of a pale rose colour with slightly bluish flowers : 

 the subterranean scaly leaves each form a kind of pitcher apparently for the pur- 

 pose of catching insects. 



Order 7. Lentibulariaces. Only the two antero- lateral stamens 

 are developed (Fig. 444 G) : ovary unilocular : ovules numerons on 

 a free central placenta : seed without endosperm. 



The numerous species of Utricularia are floating water-plants with finely 

 divided leaves bearing bladder-like appendages (modified leaflets) which serve to 

 catch small aquatic animals (Fig. 447). Pinguicula vulgaris and alpina (Butter- 

 worts) are small plants growing in damp places, with rosettes of radical leaves 

 which catch insects by their viscid secretion. 



Cohort III. Polemonlales. Flowers generally regular, but 

 zygomorphic in consequence of oligomery in the gynseceum ; pen- 

 tamerous : stamens epipetalous : ovary of two, rarely five, carpels : 

 leaves usually scattered and 

 exstipulate : the inflorescence is 

 often cymose, with a terminal 

 flower : formula jKT (5) (0(5) ^5) 

 (?'-» to (»). 



Order 1. Con volvulace^. 

 Usually two median carpels 

 forming a bilocular ovary, with 

 1-2 anatropous ovules in each ^'<^- ^''•~ B'adders of utricularia. a 



, , , n 1 1, Outside view : « pedicel ; o entrance ; t and 



locnlus : the corolla has usually ^ bristly appendages. B Section: V a valve 



a contorted eestiv^ation, twisted opening inwards and preventing the exit of 



to the right : fruit a septif ragal '''' i°^P"«oned aninaal (mag.). 



capsuJe, or a berry : seed with endosperm. Commonly plants 

 climbing by twining stems : with milky latex. 



Convolvnlus arvensig, the lesser Bindweed (Fig. 329 A), and Calystegia 

 Sepium, the larger Bindweed, the former with two small bracteoles, the latter 

 with two large bracteoles which invest the calyx, and C. Soldanella, the Sea- 

 Bindweed, are common wild plants. Jiatatas eduUs is cultivated in tropical 

 America for its edible tuberous rhizome, the Sweet Potato. 



The genus Cuscuta consists of parasites destitute of chlorophyll, with filiform 

 twining stems, which attach themselves to other plants by means of haustoria 

 (see p. ()6), and derive their nourishment from them : the small flowers are 

 arranged in fascicles (Fig. 448 h) : the corolla has imbricate aestivation : fruit a 

 capsule with transverse dehiscence. 



Custcnta europ(pa, the greater Dodder, which occurs commonly on Nettles and 

 Hops, is widely distributed : C. Epilinum is the Flax Dodder, and C. Epithymum, 

 the lesser Dodder, occurs on various low-growing plants ; C. Trifolii attacks 

 Clover, which it often destroys. 



