374 



MANUAL OF POISONOUS PLANTS 



gravelly soils, has mucilaginous stems, blue ephemeral flowers, and is common 

 everywhere in eastern North America. Several species of Tradescantia, like 

 the wandering Jew (T. Zebrina), are commonly cultivated. Another family 

 of the order is the Pontederiaceae, containing the pickerel weed (Pontederia 

 cordata) and the Eichornia speciosa, which is frequently cultivated in green- 

 hoses and has become a very troublesome weed in the rivers of Florida and 

 elsewhere in warm countries. 



LILIIFLORAB 



Herbs or occasionally shrubs with endogenous stems and monocotyledon- 

 ous seeds; perianth generally well developed; flowers generally regular and 

 complete, their parts in 3's and 6's ; ovary superior, or inferior compound 

 endosperm horny or fleshy. This series contains the family Juncaceae, called 



rushes, some of which 

 like wire-grass (Juncui 

 tennis}, are troublesome 

 weeds. Luzula is com 

 mon at high altitude 5 

 and in northern states 

 The Dioscoreaceae, 01 

 Yam Farqily, contains 

 but few species in th( 

 United States. To thh 

 belong the wild yarr 

 root (Dioscorea villosa} 

 of our woods, the Jap 

 anese yam (D. divari- 

 cata} and the air po 

 tato (D. bulbifera) oi 

 Asia, sometimes culti 

 vated in the Gulf State; 

 for its large tubers 

 Yam starch is obtainec 

 from several species, th< 

 most important of whict 

 are D. alata, D. sativa 

 D. japonica, and D 

 aculeata. 



The family Taccaceai 

 contains Tacca pinnati- 



Fig. 160. Flowers, fruit and leaves of Yam (Dioscorea^ the r tS f whid " 

 villosa). A common plant in thickets. are the source of the 



Tacca starch of Tahit; 

 and the neighboring islands. The plant is grown also in Brazil and India. 



FAMILIES OF LILIIFLORAE 



Ovary mostly superior. 



Perianth segments distinct or partly united, the inner, petal-like ; 



fruit a capsule or berry Liliaceae 



