ENGELMANN OAKS OF THE UNITED STATES. 3S9 



specimens) peduncled. The form of the acorn and cup might justify me 

 in considering this bush as a distinct species, but, well aware of the 

 extreme variability of the western oaks, I provisionally append it to 

 e^. lobata as a subspecies under the name of fruticosa. 



^. Garrya?ia, Dougl. ap. Hook., well known in California by the name 

 of Mountain White-oak, though not found in the higher mountains; it 

 extends farther north than any other oak on the west coast and is the only 

 representative of the genus north of the Columbia River, is common on 

 Vancouver Island (where a variety has been called J£. jfacobi, R. Br. 

 min.) and according to Prof. Dawson has been met with sparingly on 

 Frazer River; on the Columbia it extends as high up as the Dalles ; in 

 exposed northern situations it is scrubby. Southward it seems to be lim- 

 ited by San Francisco Bay. It can always be readily distinguished by its 

 rather large, variously but commonly deeply-lobed thick leaves, tomentose 

 or downy beneath, and by its large (3-5 lines long) tomentose winter 

 buds. ^. Necri, Liebm. (Hartweg in Hb. Gray) is a form with more 

 knobby cups. 



£>_. stellata, Wang. (^>. obtusiloba, Michx ) is of a uniform character in 

 the middle States, but varies considerably southward. Dr. Mellichamp 

 finds on the coast of South Carolina, 1. a scrub form, often with almost 

 entire, undulate or angular leaves mixed with other shrubs or trees of the 

 normal foliage; 2. a tree with normal leaves but glabrous branchlets and 

 glabrous anthers; and 3. a tree with flaky bark, and narrow, cuneate 

 leaves with oval lobes, and like the branchlets glabrous ; anthers unknown. 

 The last two may prove to be hybrid forms between stellata and alba, for 

 -which see further on. 



Q. macrocarpa. Michx. often occurs in the north and northwest with 

 unusually small oblong acorns, half or more covered by the mossy cup, 

 when it is ^_ olivceformis. Michx. ; another form has oval acorns of the 

 size of those of coccinea in a shallow, mossy cup; on the lower Ohio 

 acorns have been gathered 15-16 lines in diameter, in a very mossy cup 

 over 2 inches wide. The leaves vary from the nearly entire, obovate, sinu- 

 ate-dentate to the lyrate-pinnatifid form with almost naked midrib. The 

 branchlets, always thick, are either corky or smooth. 



«^. lyrata, Walt., originally known from the banks of the southeastern 

 rivers, is also found in the damp woods of the lower Ohio and down the 

 Mississippi River. It properly stands between macrocarpa and bicolor 

 and has a good deal of both. I have seen from the same localities (Mount 

 Carmel on the lower Wabash, Dr. J. Sckneck, and Memphis, A. Fendler) 

 specimens with the typical enclosed acorns, and others with cups, some- 

 what mossy on the edge, only half enclosing the acorn. The bark is flaky 

 like that of bicolor. 



J£. bicolor, Willd. is generally a well characterized tree with flaky bark, 

 cuneate-obovate, coarsely sinuate-dentate leaves, white below, 6-8-androus 

 flowers, and large acorns in long-peduncled, mossy cups ; but numerous 

 aberrant forms occur, some with light downy leaves and green below, 



