PAGACEAE (beech FAMILY) 



339 



e. Fmit sessile or on very short peduncles. 



Gup 2.5-3 cm. broad ; scales free to the base . . . , G. Q. Michauxil. 

 Gup at most 2.6 cm. broad, only the small tips of the scales 

 distinct. 

 Leaves with acute or pointed teeth. 

 Leaves with 8-18 teeth on each mar^n .... 7. 

 Leaves with 3-7 teeth on each margin 

 Leaves with somewhat rounded teeth 



10. 



MuhUn hergii. 

 prinoides. 

 Trinus. 

 virginiana. 



12. Q^palmtrU. 



18. Q, cocoinea. 



a. Leaves coriaceous, evergreen, entire or rarely spiny-toothed 

 § t. Bark dark, furrowed ; leaves deciduous, then' lobes and teeth acute and bristle"-polnted (at 

 least in youth); stamens mostly 4-6 ; cup-scales membranaceous; styles Ions: and spread- 

 ing'; abortive ovules near the top of the perfect seed; Inner surface of shell tomentose; 

 fruit maturing the second year. — EbythrobXlanus Spach. (Red 

 or Black Oaks.) /. 

 /. Leaves pinnatlfld or lobed, slender-petioled, not coriaceous, the lobes 

 or teeth conspicuously bristle-pointed g. 

 g. Mature leaves green on both sides ; species closely related and 

 freely hybridizing A. 

 h. Longest lobes of the leaf about equaling (never twice as long as) 



the breadth of the broadish middle portion of the le^f . . 11. Q* rubra, 

 h. Longest lobes of the leaf 2-6 times as long as the breadth of the 

 narrow middle portion of the leaf i. 

 i. Scales of the cup closely appressed j. 

 J, Expanded saucer-shaped portion of the cup S-5 mm, high, 



1-1.5 cm, broad 



J, Cups larger. 



Cups brown or castaneous, the scales finally glabrate and 



lustrous 



Cups ashy with persistent dull pubescence. 

 Cup 2-2.6 cm. broad ; acorn 1.8-2.8 cm. thick . . .14. Q. texana. 

 Cup 1.2-1.8 cm. broad ; acorn 0.8-1.7 cm. thick . • 15. Q. ellipsoidalis. 

 €* Upper scales of the cup loosely imbWeated . . , . 16. $. velutina, 



g% Mature leaves whitish or grayish beneath with close down. 



Lobes elongate; at least the terminal falcate 17. Q^falcatOi, 



Lobes broadly triangular 18. ^. iUcifolia, 



f. Leaves entire or with few teeth (or somewhat 8-5-lobed at summit), 

 commonly bristle-pointed; acorns globular, small (rarely over 

 IS mm. long) k. 

 k. Leaves widening or often much dilated upward and more or less 

 sinuate or^^-lobed. 

 LeaVes glabrc^us ; cup saucer-shaped or hemispherical . . . Itf. Q. nigra. 

 Leaves rusty-pubescent beneath ; cup turbinate . . . . 20. V< ifnariUpndica. 

 lb. Leaves not dilated upward, generally entire. 



Leaves permanently stellate-pubescent beneath . . , 21. Q. imbricaria. 



Leaves glabrous or glabrate beneath . . . . 22. $. phellos, 



1. Q. dlba L. (White O.) Leaves when young 

 white-lanate beneath, when mature pale or glaucous 

 beneath, bright green above, obovate-oblong, obliquely 

 cut into 5-9 oblong or linear and obtuse mostly entire 

 lobes; cup hemispherical-saucer-shaped, rough ortuber- 

 cled at maturity, puberulent, much shorter than the 

 ovoid or ellipsoid (2-3 cm. long) acorn, — Dryish or 

 upland woods, s. Me. to Ont., Minn., and southw. 

 Fig. 670. 



2. Q. steliata Wang. (Post 

 O., Iron O.) Leaves grayish- 

 or brownish-downy under- 

 neath, dark green and rough 

 above, thickish, sinuately cut 

 into 5-7 rounded divergent 

 lobes, the upper ones much 

 larger and often IS-notched ; 



acorn 1-2 cm. long. {Q. minor Sarg. )—- Sandy or 

 sterile soil, Mass. to la., Neb., and southw. Fig. 671. 



Q. Margaretta Ashe, with narrower small leaves 

 glabrate and with lobes merely rounded at tip, is pos- 

 sibly a hybrid of Q. stellata and Q. alba. 



3. Q. lyrata Walt. (Over-cup 0., Swamp Post 0.) 

 Leaves crowded at the end of the branohlets, obovate- 

 oblong, acute at base, more or less deeply 7-9-lobed, 



Q. alba. 



Q, stellata 



