19251 PALMER, IS QUERCUS ARKANSANA A HYBRID? 199 



thrifty plant more than eight feet in height, and in foliage and other 

 characters it is quite typical and identical with the species as it grows in 

 Arkansas. Another planting was made from seeds collected by myself 

 in 1922 and some of these were transplanted to another part of the Arbore- 

 tum, but apparently the plants have not survived. Before they were 

 taken from the nursery rows I examined them carefully. There were, 

 perhaps fifty or sixty plants, with from four to ten leaves at that time, 

 every one of which was true to type and without the slightest indication 

 of segregation of forms or of reversion. At the present time there are about 

 15 plants growing in the nursery, raised from seeds collected in 1923, 

 which are now six to ten inches in height. All of these are remarkably 

 uniform and true to the parent type. Seedlings of Quercus marilandica, 

 planted about the same time, are growing just opposite in the next row. 

 The Q. arkansana seedlings compared with these are distinguished by 

 their more slender stems, the yellowish instead of bronze or reddish 

 tinge of the older leaves, and the thinner texture, more slender petioles 

 and more obtuse lobes of the latter. 



During the past few years I have paid especial attention to hybrid 

 Oaks in the field and have found, and collected from, more than one hun- 

 dred trees representing supposed crosses between many different species, 

 A number of these have been grown from seeds at the Arnold Arboretum 

 and others have been propagated from grafts. In the case of the former, 

 while unfortunately we have not been able to grow them in the quantity 



purposes 



Mendel 



Q 



nothing of the sort has ever developed. In most of the hybrid Oaks with 

 which I am acquainted there is a certain instability of type and poly- 

 morphism in foliage and other parts, not only between different individuals 

 but also on different branches of the same plant, and a lack of uniformity 

 and symmetry in the individual leaves, which easily betrays them. This 

 is not found in the Oak we are considering, beyond the slight variations 



nea 



Q 



so 



local abundance both at the Alabama and Arkansas stations, is probably 



Mohr 



hybrid origin, 

 not unknown ; 



cases 



Leitneria Jloridana, Cotinns 



Quercus 



Andrachne phyllanthoides come to mind. A score of other examples 

 might be mentioned of trees and shrubs of the Southern Appalachian 

 region, of which isolated colonies now exist in widely separated intervals 

 through the mountainous parts of southern Arkansas and eastern Okla- 

 homa; and if herbaceous species were taken into consideration more 



