Genus 3. 



BEECH FAMILY. 



617 



Q. stellata. 



Q. lyrata. 



Q. macrocarpa. 



** Leaves or their lobes not bristle-tipped, deciduous; acorns maturing in autumn of first year. 



t Leaves pinnatifid or pinnately lobed. 



Mature leaves pale, or glaucous and glabrate beneath ; cup shallow. 16. Q. alba. 



Mature leaves tomentulose beneath ; cup one-third to fully as long as the acorn. 

 Upper scales of the cup not awned. 



Leaves yellowish-brown-tomentulose beneath ; acorn ovoid. 

 Leaves white-tomentulose beneath ; acorn depressed-globose. 

 Upper scales awned, forming a fringe around the acorn. 



tt Leaves crenate or dentate, not lobed. 

 Fruit peduncled. 



Peduncle much longer than petioles ; leaves white-tomentulose beneath. 20. Q. bicolor. 

 Peduncle equalling or shorter than the petioles ; leaves gray-tomentulose beneath. 



Teeth of the leaves acute or mucronulate. 21. Q.Michauxii. 



Teeth of the leaves rounded. 22. Q. Prinus. 

 Fruit sessile or nearly so. 



Tall tree; leaves oblong, obovate or lanceolate. 23. Q.Muhlenbergii. 



Shrub or low tree ; leaves ov'al or obovate. 24. Q. prinoides. 



*** Leaves entire {rarely with a few bristle-tipped lobes), evergreen. 25. Q.virginiana. 



i. Quercus rubra L. Red Oak 



Quercus rubra L. Sp. PI. 996. 1753. 



A large forest tree, with a maximum height of 

 about 140 , and a trunk diameter of 7°, the bark 

 dark gray, slightly roughened. Leaves oval or some- 

 what obovate in outline, deciduous, when mature 

 glabrous, or pubescent in the axils of the veins be- 

 neath, 4'-8' long, 3'-6' wide, dull green above, paler 

 beneath, sinuses rounded, lobes triangular-lanceolate, 

 tapering from a broad base to an acuminate apex, 

 1-4-toothed or entire, teeth and apices tipped with 

 filiform bristles; petioles ii-3' long; styles slender, 

 spreading; fruit maturing the second autumn, sessile 

 or nearly so; cup saucer-shaped, its base flat or 

 slightly convex, 8"-i2" broad, bracts ovate or ovate- 

 lanceolate, obtuse or the upper acute, appressed; 

 acorn ovoid, about 1' long, 2-4 times as long as 

 the cup. 



Nova Scotia to Ontario and Minnesota, south to 

 Florida and Kansas. Wood hard, strong, coarse-grained ; 

 color light reddish-brown ; weight per cubic foot 41 lbs. 

 May-June. Acorns ripe Oct.-Nov. Champion, Black 

 or Spanish oak. 



Quercus rubra runcinata A. DC. with leaf-lobes 

 nearly entire and acorn J4' high, from near St. Louis, is perhaps a hybrid with Q. triloba Michx. 



Quercus Catesbaei Michx., a tree of the southeastern states, differs from all related species by 

 having the inner scales of the deep cup of the acorn inflexed. It has been observed northward to 

 southern Virginia. 



2. Quercus palustris DuRoi. Swamp Oak. Pin Oak. Fig. 1515. 



Q. palustris DuRoi, Harbk. 2: 268. pi. 5. f. 4. 1772. 



A forest tree, maximum height about 120 and 

 trunk diameter 5°, the lower branches deflexed; 

 bark brown, rough when old. Leaves broadly 

 oblong or obovate in outline, deeply pinnatifid, 

 sometimes almost to the midrib, bright green 

 glabrous and shining above, duller, glabrous or 

 with tufts of hairs in the axils of the veins be- 

 neath, 3'-s' long, the lobes oblong, lanceolate 

 or triangular-lanceolate, divergent, 1-4-toothed 

 or entire, teeth and apices tipped with filiform 

 bristles; styles slender; fruit maturing in the sec- 

 ond autumn ; cup saucer-shaped, 4"-6" broad, 

 base flat, bracts triangular-ovate, acute or obtuse, 

 appressed ; acnrn subglobose or ovoid, 4." -7"' 

 high, often striate, 2-3 times as long as the cup. 



In moist ground, Massachusetts to Michigan, Vir- 

 ginia and Arkansas. Wood hard, very strong, coarse- 

 grained ; color light brown ; weight per cubic foot 43 

 lbs. May-June. Acorns ripe Sept.-Oct. Swamp 

 Spanish oak. 



