INTRODUCTION. 



The State of Texas, an empire in itself, comprising one-twelfth of the 

 area of the United States, with great diversity of soil and climate, must 

 necessarily present a corresponding diversity in plant life. When all of 

 its immense area is thoroughly explored it will undoubtedly yield as 

 many or perhaps more species than are contained within the limits of 

 Gray's Manual. 



As is stated in the Introduction to the Botany of the Mexican Bound- 

 ary Survey, a line drawn from the Pan Handle southeast to the vicinity 

 of Corpus Christi divides the State into two unequal portions. The 

 smaller eastern part is well watered as a whole, and gives rise to more 

 luxuriant vegetation than the other, where rain is uncertain and often 

 scanty. The flora of this eastern section, at least in its northern and 

 eastern portions, has many species in common with the adjacent States 

 of Louisiana and Arkansas and the Indian Territory. 



In the Contributions from the U. S. National Herbarium, "Upon a 

 Collection of Plants made by Mr. G. C. Neally, in the Region of the 

 Rio Grande in Texas, from Brazos Santiago to El Paso County," sixty- 

 four species of Cyperaceae are mentioned. Four of these have no 

 station assigned, while forty-seven were collected about Sabine Pass in 

 extreme eastern Texas, near the mouth of the Sabine river. As the 

 plants of this order are usually frequenters of places where there is an 

 abundance of moisture, we have a very good index to the character of 

 the country where they are found. 



The larger southern and western division, in many places a veritable 

 desert, contains many peculiar plants, found only within its areas, es- 

 pecially in the central portions, in the limestone foothills, and in the 

 mountains of the extreme western part. Along the southern border the 

 species are essentially Mexican, intermingling in the mountain region 

 with more northern forms found in the mountains of New Mexico and 



