178 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 

 2. TRADESCANTIA*) Spiderwort 



Plants perennial, with thickened roots; outer one or more of the 

 bracts leaflike, the inner ones scarious ; inner perianth segments purple, 

 all alike. 



These plants were used by the Indians as potherbs and the tuberous 

 roots of T. pinetorum are said to have been eaten also. 



Key to the species 



1. Roots partly tuberous-thickened, fascicled at base of the stem or borne on a 

 creeping rootstock; stems slender, hispidulous, commonly unbranched; 

 sheaths pubescent or puberulent, especially on the margins; corolla not 

 more than 2 cm. in diameter 1. T. pinetorum. 



1. Roots thick but not tuberlike, the rootstock none; stems stout, glabrous, often 

 branched; sheaths glabrous; corolla often more than 2 cm. in diameter. 



2. T. OCCIDENTALS. 



1. Tradescantia pinetorum Greene, Erythea 1: 247. 1893. 

 Apache and Coconino Counties to Cochise and Pima Counties, 



often in pine woods, 4,500 to 9,300 feet. New Mexico and Arizona, 

 probably also in northern Mexico. 



Flowers handsome, the inner perianth segments violet or purple. 



2. Tradescantia occidentalis (Britton) Smyth, Kansas Acad. Sci- 



Trans. 16: 163. 1899. 



Tradescantia virginiana L., var. occidentalis Britton in Britt. 

 and Brown, Illus. Flora 1:377. 1896. 



Apache, Navajo, and Coconino Counties, south to Graham and 

 Pima Counties, 2,500 to 7,000 feet. Wisconsin to Montana, Texas, 

 and Arizona. 



The var. scopulorum (Rose) Anderson and Woodson (T. scopulorum 

 Rose) is about as frequent and as widely distributed in Arizona as the 

 typical form, which has the sepals and pedicels more or less glandular- 

 pubescent, whereas they are glabrous in the variety. The type of 

 T. scopulorum was collected in the Santa Catalina Mountains, Pima 

 County (Pringle in 1884). 



15. PONTEDERIACEAE. Pickerelweed family 



1. HETERANTHERA. Mud-plantain 



Plants herbaceous, aquatic or semiaquatic; leaves alternate, with 

 broad blades or narrow and grasslike; flowers perfect, somewhat 

 irregular, the perianth corollalike, of 6 segments; stamens 3, inserted 

 on the perianth; ovary fusiform, 1-celled or incompletely 3-celled. 



Key to the species 



1. Leaves linear, grasslike; perianth yellow 1. H. dubia. 



1. Leaves with long stout petioles and ovate blades rounded at base; perianth 

 commonly blue, sometimes white 2. H. limosa. 



1. Heteranthera dubia (Jacq.) MacMillan, Met. Minn. 138. 1892. 



Commelina dubia Jacq., Observ. Bot. 3: 9. 1768. 



Irrigation canals in the Salt River Valley, Maricopa County 

 (Loomis 5537) . Ontario to Washington, North Carolina, and Arizona. 



20 Reference: Anderson, E., and Woodson, R. E. the species of tradescantia indigenous to the 

 united states. Arnold Arboretum Contrib. 9: 1-132. 1935. 







