484 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



Tetraclea Coulteri. 

 Eriogonum annuum, 

 Croton corymbulosus. 

 Asclepias JaMesii. 

 Senecio longilobus. 

 Gaillardia pulchella. 

 Biddellia tageiina. 

 Aplopappus spinulosus. 

 Gutierrezia criocarpa. 

 Lygodesmia aphylla. 

 Aster tanacetifolius. 

 Thelesperma gracile. 



That large portion of Southeastern Texas included between the coa«t, 

 the Eio Grande and the Nueces River, is a sandy, dry, riverless country, 

 but mostly covered with fair grass, and therefore entitled to consid- 

 eration under the heading of prairie. On account of its peculiar vege- 

 tation I have deemed best to describe it separately. 



Zones of chaparral and small timber traverse it in several directions, 

 and trees of good size : Hackberry, Mezquit, Huisache, rarely Wa- 

 ter Elm and Green Ash, fringe the dry forks and beds of the Olmos, 

 San Diego, and Banquete Creeks. The absence of surface water and 

 the uncertainty of obtaining it by deep boring, render the settlement of 

 much of this vast region problematical. 



Following the narrow-gauged railroad from Laredo, one crosses the 

 chaparral belt, extending nearly 40 miles out ; then begin undulating 

 plains of red sand covered mostly with a coarse bunch-grass (stout, 

 nearly smooth, form of Elionurus ciliatus) ; Aristida purpurea and Sporo- 

 bolus cryptandrus are also common, and always abundant about settle- 

 ments the very obnoxious Sand-bur {Cenchrus trihuloides). Near the 

 Kio Grande and the coast, the Texas Grama [Bouteloua Texana) and 

 Bermuda Grass {Cynodon Dactylon) are common, while the Common 

 Grama {Bouteloua oligostachya) is only rarely seen. 



The open, grassy plain is about 35 miles in width, measured by the 

 railroad track. Ten or 15 miles eastof PeQa Station the shrubbery be- 

 gins again and grows denser and larger until San Diego is reached. 

 Farther on, it decreases and dwindles down to scrubby chaparral, which 

 in places entirely disappears, leaving the ground covered with thin 

 and sparse grass or, in dry seasons, quite bare. Beyond Collins the 

 level land is lined for miles with a thick sod of excellent grass. 



On approaching Corpus Christ! the chaparral becomes thicker, but 

 remains low and stunted. Clumps or " motts " of Live Oak occur far- 

 ther south on the sandy plains between the Olmos, the Rio Grande, and 

 the coast ; the trees are small and not of much account. 



Peua Station stands in the midst of the central grassy plain described 

 above. The loose, sandy soil is mostly covered with the form of Elio- 



