544 



A TEXTBOOK OF BOTANY 



[Ch. XIII 



Order 9. Arjstolochiales : the Birthworts and kin. 

 About 200 species of herbs and vines, with apetalous flowers 

 elaborately specialized as to the calyx, which has remarkable 

 tubular-flaring forms (Fig. 388), and moreover is often dark- 

 colored and ill-smelling in fitness to pollination by carrion 



insects. The common Wild 

 Ginger (Asarum), and the 

 Dutchman's Pipe, a porch 

 vine, are familiar representa- 

 tives. A number have minor 

 medicinal uses, and some had 

 formerly high repute, in ways 

 expressed by their name. Here 

 belongs Rafflesia, the gigantic- 

 flowered parasite earlier de- 

 scribed (Fig. 61). 



Order 10. Polygon ales : the 

 Knotweeds and kin. About 

 700 species, mostly herbs of 

 northern temperate regions, 

 distinguished by their soft 

 bodies, swollen nodes, sheath- 

 ing stipules, and simple flowers 

 in clusters. Some contain acids 

 in leaves or stem, as in Sorrel 



.i„ton r :^etLta r 'rrL a o S v e et ^ Rhubarb - While the l ^ 

 and an older seedling, the branch in starchy Seeds give Value to 



section. (From Warming.) Buckwheat, an important cereal 



crop. Here belong several dooryard weeds, and some 

 aquatics with pretty pink flowers and floating leaves. 



Order 11. Chenopodiales: the Goosefoots and kin. 

 About 1800 species of rather heterogeneous herbs. They 

 include some ugly dooryard weeds with wind-pollinated 

 flowers, the Pokeweed with purple berries, the Samphire, 

 a succulent red annual of salt shores (Fig. 389), the Amaranth 



Fig. 386. — The Mistletoe, Vis- 

 cum album; reduced. 



