568 



BOTANY 



PART II 



it develops into the fruit (Fig. 547). Species oi Rheum are cultivated as ornamental 

 plants and as vegetables. Rumex acetosa (""), Sorrel, with sagittate leaves. The 

 structure of the flowers of the hermaphrodite species oi Rumex is similar to that of 

 Rheum, but the inner whorl of stamens is wanting. The species of Polygonum have 



Fig. 548. — Beta vulgaris. 1. Upper iiortion of the root witli 

 the rosette of leaves, the blades of which are cut otf. 

 (Greatly reduced.) S, Branch of the inflorescence (i nat. 

 size). .T, Singli' flower, i, Flower cut through longi- 

 tudinally (5 and /, enlarged). 



Fig. 540.— l>ia,sranis of the C'aryo- 

 phyllaceae. A, Viscnna, septa 

 present in the lower part of 

 the ovary ; B, SUene, septa 

 absent. (After Eichler) 



a perigone consisting of five coloured leaves and a varying number of stanieu.s. 

 The triangular fruits oi Fagopyrmn esculmtum form Buckwheat (Fig. 487). 



Okfictai,.— The Rhizome of Rheum officinale, Rh. 2'>almatum, and probably other 

 species yields kadix uiikt. 



Family 2. 

 small woody 



Chenopodiaeeae. — Perennial or annual herbs, rarely 

 plants, with alternate leaves. Flowers typically 



