Seed Plants. Ferns, Fern Allies of the Austin Region 23 



Toxylon pe Rai. Bois D'Arc. Bowwood. Osage Orange. 



Low ground. Ravines and valleys. 

 Southeastern states. 



ULMACEAE Elm Family 



Celtis ynississippiensis Bosc. Hackberry. 



Very common on hills and in ravines. The most common shade 

 tree in Austin. 



Central and southeastern states. 



Celtis reticulata Torr. Hackberry. 



On dry hills. Similar to the preceding, but with rough leaves 

 and large berries. 



A species of the arid southwest. In wester:: Texas it occurs near 

 streams. 



Ulmus alata Michx. Winged Elm. Cork Elm. Wahoo. 



Abundant in ravines and valleys. Easily recognized by the con- 

 spicuous corky wings on the branches. Flowering in spring. 



Southern states. 



Ulmus amerieana L. White Elm. 



On the river flood plain and in ravines. D ifferin g from the other 

 species in its large, thin leaves. Used as a shade tree. Flowering 

 in spring. 



Eastern United States. 



I" —folia Xutt. Cedar Elm. 



Abundant in ravines and uplands. A common shade tree in Aus- 

 tin flowering in the fall. Leaves leathery, blades 3-o cm. long. 



Along rivers in the southern central prairie states. 



POLYGONALES 



POLYGONACEAE Buckwheat Family 



ganum lomgi folium Xutt. 

 Dry ground. 

 Southern central states. 



Persicaria hydropiperoides Small. {Pol% hydropiperoides 



Michx.) Wild Water-pepper. 



Ditches and along streams. 

 Widespread in North America. 



