16 University of Texas Bulletin 



ARALES 



ARACEAE Arum Family 



Muricauda Dracontium Small. (Arisaema dracontium Schott.) Green 

 Dragon. Dragon Root. 



Moist rich soil on shaded bluffs of the Colorado River and Bull 

 Creek. 



Eastern and Central states. 



LEMNACEAE Duckweed Family 



Lemna cyclostasa Chev. 



Waller Creek. Similar to the following but obscurely one nerved 

 plant, body oblong or nearly so. 



Widespread in the United States. Also in Jamaica and South 

 America. 



Lemna minor L. Duckweed. 



Abundant in stagnant pools and in still water of creeks, forming 

 a green scum over the water. The plant is a thin disk-like body 

 about 4 mm. in diameter with a single root. From oval to nearly 

 circular with a papillate midrib. 



Widespread over almost the whole of North America. 



XYRIDALES 

 COMMELINACEAE Spiderwort Family 



Commelina angustifolia Mich. (?) 



Commelina crispa Wooton. Curly-leaved Day-flower. Leaves crisped. 

 Rocky hillsides. 

 Southern central states. 



Commelina erecta L. Day Flower. 

 Southeastern United States and tropical America. 



Commelina virginica L. Day Flower. 

 Moist hillsides. 

 Central and southeastern United States and tropical America. 



Tradescantia gigantia Rose. Spiderwort. 

 Fields and roadsides. 

 A tall, erect species with a stout stem two or three feet high. 



Tradescantia occidentalis Brit. Spiderwort. 

 Rocky hillsides. 

 Central states to the Rocky Mountains. 



