Some notes on plants of Trans-pecos Texas 



C. H. Mueller 



During the summers of 1931, 1932, and 1933 the author col- 

 lected plants in the Chisos Mountains of Western Texas over a 

 total period of about six months. In the course of that time cer- 

 tain problems suggested themselves. The larger of these will be 

 dealt with later as time permits, and only some minor ones will 

 be given consideration here. 



An abundant collection of Fraxinus Greggii Gray yielded 

 such wide variation as to have caused a part of it to be identified 

 as F. nummularis Jones. Standley in "Trees and Shrubs of 

 Mexico" 1 allows F. nummularis specific rank but very pointedly 

 suggests that it is but a form of F. Greggii bearing a reduced 

 number of leaflets. The author's collections in Western Texas 

 definitely bear out Mr. Standley's contention. 



Fraxinus Greggii Gray (Proc. Am. Acad. 12: 63. 1877) is de- 

 scribed in part as follows: "leaflets usually 5 or 7, . . . obtuse, 

 glabrous, . . ." 2 and, "leaflets 3 to 7, from narrowly spatulate 

 to oblong-obovate, obtuse, obtusely few-toothed or entire, firm 

 coriaceous, . . ." 3 F. nummularis Jones (Contr. West. Bot. 12: 

 59. 1908), "leaves mostly simple but sometimes trifoliate, the 

 simple leaves oblanceolate to oval, . . . obtuse, glabrous, sub- 

 coriaceous." 4 



Plants were noted in the Chisos Mountains which fitted well 

 each of these two descriptions, but there were also individuals 

 which exhibited simple, trifoliate, and 5- and 7-foliate leaves all 

 on the same main branch. This was repeatedly observed and is 

 here cited as proof that F. nummularis Jones is merely a form of 

 F. Greggii Gray. 



A series of specimens illustrating this relationship is pre- 

 served in the author's personal herbarium at Cuero, Texas. 



Phlox mesoleuca Greene is commonly scattered on the less 

 wooded slopes of the Chisos Mountains from 5500 to 7000 feet 



1 Contr. Nat. Herb. 23: 1135. 



2 Ibid., p. 1134 



3 Contr. Nat. Herb. 2: 259. 



4 Contr. Nat. Herb. 23: 1135. 



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