Some new oaks from Western Texas 



C. II. MUELLBB 



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

 made a study of the vegetation of the Chisos Mountains of 

 Western Texas. Certain inconsistencies in the identification of 

 the oaks collected and those already in the herbarium of the 

 University of Texas suggested a need for further study of that 

 group. While making a special collection for this purpose the 

 author came upon material which confirmed earlier suspicions 

 of one or more undescribed species. 



Both species herein described have been referred to Quercus 

 texana var. chisosensis Sarg., and it was not until a collection 

 of mature fruits was made that the several other smaller differ- 

 ences could be recognized as critical. It has been found that 

 the material collected not only does not agree with Sargent's 

 description of Quercus texana var. chisosensis but also differs 

 from the typical examples of that variety found growing abun- 

 dantly over the mountains. 



Quercus robusta Mueller, sp. nov. Ramuli graciles dense 

 breviterque stellato-pubescentes aut demum glabrati; gemmae 

 1.5 mm. crassae 3-4 mm. longae ex oblongis acute ovoideae; 

 folia decidua coriacea, auctumno non rubescentia, late lanceo- 

 lata del acute ovatae, basi rotundata, late cuneata, truncata, 

 vel leviter cordata, 2.5-5 cm. lata, 6-11 cm. longa, dentibus 

 8-10 setaceis, pubescentia pilis fasciculatis utrinque persistenti- 

 bus; petioli 0.5-1 mm. lati, 10-20 mm. longi, stellato-pubes- 

 centes; fructus annuus solitarius breviter pedunculatus; cupula 

 parva; glans oblonga fere cylindrica, apice rotundata, 8-10 mm. 

 crassa, 17-22 mm. longa, puberula, ad partem circa tertiam 

 inclusa. 



Quercus robusta differs from Quercus texana var. chisosensis 

 chiefly in its almost cylindrical fruit, the stiff, heavier branch- 

 lets, and the stiff, coriaceous, pubescent leaves which do not 

 turn red in autumn. Apparently its alliance is with typical 

 I Quercus texana Buckl. 



Quercus robusta Mueller, sp. nov. Twigs somewhat slender 

 (2 to 3 or rarely only 1.5 mm.), obscurely fluted, densely short 

 stellate hairy the first year or late glabrate, dark red-brown be- 



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