496 



BOTANY. 



Order Amarantacese. — Herbs, rarely shrubs, whose flowers have a 

 scarious perianth. The order, which contains about 500 species, is 

 mostly tropical, a few occurring in temperate climates, but none at all 

 in cold ones. 



In India some of the species are cultivated for their starchy seeds, 

 which are used for food. 



Several species are cultivated with us for their ornamental foliage, 

 (Aehyranihes) or their colored inflorescence, e.g., 

 Cock's Comb (Odosia), Globe Amaranth (Gomphre- 

 na), etc. 



Ama/rantus retroflexus and A. albus, are common 

 weeds in fields ; the latter, in the prairie region, 

 grows in a globular form, and in the autumn breaks 

 off" at the root, and is blown for miles across the 

 country. On account of this habit of growth it is called the " Tumble 

 Weed." 



Order Polygonacese. — The Buckwheat Family. Herbs, shrubs, or 

 rarely trees, mostly with sheathing stipules aud knotted-jointed stems ; 

 perianth often petaloid. The 600 species constituting the order are 

 mostly natives of temperate regions. 



Fagopyrum eseulentum, Buckwheat, a native of Central or Northern 



Hg. 411.— Section 

 of seed of Chenopo- 

 dium. Magnified. 



fias. 413-15.— Illubtrations of Pagoptrum esculbntum. 



Fio. 412. 



Fig. 412.— Flower. Magnified. 

 Fig. 414.- Pistil. Magnified. 



Fig. 413. 



Fie. 414. Fig. 415. 



Fig. 413.— Diagram of flower. 

 Fig. 415.— Fruit. Magnified. 



Asia, is now extensively grown in Europe and America for its nutri- 

 tious seeds, and for its honey-producing flowers. (Figs. 413-15.) 



Polygonum amphibium, var. terreatre, a native of the United States, 

 has been used in the Mississippi valley as a substitute for bark in the 

 process of tanning. It contains a considerable quantity of tannin. 



Rlieum officinale. Oriental Rhubarb, is a native of Southeastern 

 Asia; its roots constitute the officinal Rhubarb. Other species are 

 often used as substitutes. 



