460 PROCEEDINGS OF THE ACADEMY OF [Part III 



value. In this manner, group by group, should all our vast body 

 of herbarium-conclusions be checked and re-valued in the field! 



The tribe least studied in this area is the Gratioleae. These 

 are summer-blooming and unfortunately were not included among 

 the special objects of search of my first journey. However, only 

 in Gratiola do I feel this loss, and it remains for some future worker 

 to give us needed information of G. gracilis and G. flava. Most 

 of the tribe but slightly enter the area from the East Gulf states 

 and are species well-known eastward. Of other tribes, I par- 

 ticularly deplore not finding in blossom Leucophyllum, said to be 

 one of the finest ornamental shrubs of Texas. Species of still 

 other tribes were missed, but, while it would have been a pleasure 

 to have seen what must be among the most showy members of their 

 respective genera, Penstemon tnurrayanus and Castilleja pur- 

 purea, yet such distinct species are not in need of close analysis. 



When the attempt is made to express in terms of natural areas 

 of distribution the ranges of various species over an area such as 

 this, one realizes how far ahead is still any comprehensive out- 

 lining of phytogeographic areas in our country. However, I have 

 tried to use terms that have some definiteness, physiographic or 

 geologic. In Louisiana and eastern Texas we have some prelimin- 

 ary sketches by Roland M. Harper^, in Texas the outlines of 

 Vernon Bailey^ W. L. Bray^, and R. T. Hill^, and in both Texas 

 and Oklahoma excellent geological maps. In each state careful 

 state surveys of plant and animal distribution are needed, and 

 such tasks should call forth local enthusiasm. Mr. Bailey's study 

 is the most accurate of those seen, and applies carefully the 

 system of life-zones evolved by the Biological Survey. Al- 

 though I am an ardent devotee of this system when applied in 

 mountainous regions, I can but wonder what value a life-zone 

 outline can be in such a land as Texas. Life-zones lay stress upon 

 the one factor of temperature ; in the Rockies and Andes the limits 

 of bands of temperature-controlled vegetation are distinct enough, 

 but surely across flat and rolling Texas the student of distribution 

 must pay more attention to moisture and soil. However, for 



* Bull. Torr. Bot. Club 47: 289-317. /. 1-5. 1920. 

 3N. Am. Fauna 25: 1-222. pi. 1-16, f. 1-24. 1905. 



* Bull. Univ. Texas 82: 1-108. pi. 1-14, f- 1-4- 1906. 



^ Physical Geography of the Texas Region (Topog. Atlas U, S. A., Folio 3) 

 1-12. /. 1-66. 1900. 



