1925] PALMER, IS QUERCUS ARKANSANA A HYBRID? 195 



RUBIACEAE. 



Cephalanthus occidentalis L. Common. 



CAPRIFOLIACEAE. 

 Viburnum rufidulum Raf. Common. 



IS QUERCUS ARKANSANA A HYBRID? 



Ernest J. Palmer 



In looking over Dr. Trelease's recently published monograph of the 

 American Oaks 1 I note that Quercus arkansana Sargent is there treated 

 as a hybrid, Quercus marilandica Muenchhausen and Quercus nigra Lin- 

 naeus being given as the parent species. As only a list of the hybrids is 

 given without descriptive notes the author does not state the grounds 

 upon which he arrives at this conclusion, although in a foot-note a state- 



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arkansana, and which Dr. Trelease also includes under the same hybrid 

 parentage, to the effect that it does not there grow in association with 

 Quercus marilandica, a circumstance which, as we shall see, is also largely 

 paralleled in the Arkansas localities. 



Since few botanists have had a chance to see this comparatively rare 

 Oak growing in its native habitat or even to become acquainted with it 

 through herbarium specimens, it may be worth while to give a brief 

 resume of the facts known regarding it. 



Quercus arkansana was first found in Arkansas by Mr. B. F. Bush, in 

 1909, growing along Yellow Creek, a small tributary of Little River, 

 near Fulton, or more exactly near the village of McNab, Hempstead 

 County, and was described by Professor Sargent 2 from specimens collected 

 there by Bush and later by himself. If the Alabama Oak is specifically 

 identical, as I believe to be the case, its first discovery must be credited to 

 Dr. Charles C. Mohr, who collected it along a small tributary of the 

 Conecuh River in 1880, and it was he also who first suggested the theory 

 that it was a hybrid between the species mentioned by Dr. Trelease. Dr. 

 Mohr does not mention this Oak in his Plant Life of Alabama, nor does 

 he appear to have published anything about it elsewhere. 



Dr. Harper explored the Alabama locality in 1912 and published an 

 interesting account of the flora, 3 including a foot-note on the Oak, which 

 he regarded as an undescribed species. A sheet of the specimens collected 



$ l A 



by Mohr (no. 22, July 4, 1880. "Quercus.— aun [?] var. hybrid inter Q 

 aquatica et nigra. Arb. gracilis 20-24' alt. trunco 2 



1 Mem. Nat. Acad. Sci. xx. (1924). 



2 Trees & Shrubs, n. 121-122, pi. 152 (1911). 



* The "pocosin" of Pike County, Alabama, and its bearing on certain problems 

 of succession. (Bull. Torrey Bot. Club, xli. 209-220 [1914].) 



