PAGACEAE (BEECH FAMILY) 



339 



. Fruit sessile or on very short peduncles. 



Cup 2.5-3 cm. broad; scales free to the base .... 6. Q. Michawxiii. 

 Cup at most 2.5 cm. broad, only the small tips of the scales 



distinct. 



Leaves with acute or pointed teeth. 



Leaves with 8-13 teeth on each margin . . . 7. Q. Muhlenbergii. 



Leaves with 3-7 teeth on each margin . . . 8. Q. prinoides. 



Leaves with somewhat rounded teeth 9. Q. Prinus. 



a. Leaves coriaceous, evergreen, entire or rarely spiny-toothed . . 10. Q. virginiana. 

 2. Bark dark, furrowed ; leaves deciduous, their lobes and teeth acute and bristle-pointed (at 

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

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

 fruit maturing the second year. ERYTUROBALANUS Spach. (RED 

 or BLACK OAKS.) /. 

 /. Leaves pinnatifld 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 h. 

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



the breadth of the broadish middle portion of the leaf . . 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 *. 

 *. Scales of the cup closely appressed j. 

 j. Expanded saucer-shaped portion of the cup 3-5 mm. high, 



1-1.5 cm. broad 12. Q.palustrts. 



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 1.8-2.3 cm. thick 



13. Q. coceinea. 



'. texana. 



ellipsoidalis. 

 '. velutina. 



Cup 1.2-1.8 cm. broad ; acorn 0.8-1.7 cm. thick 

 i. Upper scales of the cup loosely imbricated . . . 

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



Lobes elongate, at least the terminal falcate 17. Q.falcata. 



Lobes broadly triangular 18. Q. ilicifolia. 



'. Leaves entire or with few teeth (or somewhat 3-5-lobed at summit), 

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

 13 mm. long) k. 

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



sinuate or 3-5-lobed. 



Leaves glabrous ; cup saucer-shaped or hemispherical . . . Is*. Q. nigra. 

 Leaves rusty-pubescent beneath ; cup turbinate . . . . 20. Q. marilandica. 

 k. Leaves not dilated upward, generally entire. 



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

 Leaves glabrous or glabrate beneath 22. Q. phellos. 



670. Q. alba. 



1. Q. alba 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 south w. 

 FIG. 670. 



2. Q. stellata Wang. (Posr 

 O., IRON O.) Leaves grayish- 

 or broionish-downy under- 

 neath, dark green and rough 

 above, thickish, sinuately cut 

 into 5-7 rounded divergent 

 lobes, the upper ones much 

 larger and often 1-3-notched; 



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

 sterile soil, Mass, to la., Neb., and south w. 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 O., SWAMP POST O.) 

 Leaves crowded at the end of the branchlets, obovate- 

 oblong, acute at base, more or le.sa deeply 7-9-lobed, 



671. Q. stellata. 



