,520 



FAGACEAE. 



12. Quercus imbricaria Michx. Shingle Oak. (Fig. 1239.) 



Quercus imbricaria Michx. Hist. Chen. Am. g. pi. 75, 



16. 1801. 



A forest tree, with maximum height about 100, 

 and trunk diameter of 3,^. Leaves oblong or 

 lanceolate, entire, coriaceous, acute at both ends, 

 short-petioled, bristle-tipped, dark green above, 

 persistently gray-tomentulose beneath, $'-7' long, 

 9 // -2 / wide; styles recurved; fruit maturing the sec- 

 ond autumn; cup hemispheric or turbinate, 5" '-]" 

 broad, its bracts appressed; acorn subglobose, 5"- 

 V high. 



Central Pennsylvania to Michigan, Nebraska, Geor- 

 gia, Tennessee and Arkansas. Wood hard, coarse- 

 grained, light reddish-brown; weight per cubic foot 

 47 Ibs. April-May. 



Quercus Leana Nutt. Sylva, i: 134, pi. 56, is a hybrid 

 of this and Q. velutina, with intermediate characters. 

 Ohio to Missouri and District of Columbia. 



Quercus tridentata Engelm, Q. nigra var. tridentaia 

 A. DC. Prodr. 16: Part 2, 64, is a hybrid with Q. Mary- 

 landica. Illinois and Pennsylvania. 

 A hybrid with O. palustris was found by Dr. Engelmann near St. Louis, Mo. 



13. Quercus alba L,. White Oak. (Fig. 1240.) 



Quercus alba L- Sp. PI. 996. 1753. 



A large forest tree, with light gray bark scaling 

 off in thin plates; maximum height about 150, 

 trunk diameter 8. Leaves obovate in outline, 

 green above, pale and more or less glaucous be- 

 neath, pubescent when young, nearly glabrous 

 when old, thin, pinnatifid into 3-9 oblong obtuse 

 ascending toothed or entire lobes, 4 / -7 / long, i f - 

 4^' wide; petioles about y 2 ' long; styles short, 

 erect; fruit maturing the first season, peduncled; 

 cup depressed-hemispheric, 7 // -io // broad, its 

 bracts thick, obtuse, woolly or at length glabrate, 

 closely appressed; acorn ovoid-oblong, i' high or 

 less, 3-4 times as high as the cup. 



Maine to Ontario, Minnesota, Florida and Texas. 

 Wood hard, strong, tough, close-grained; color brown; 

 weight per cubic foot 46 Ibs. May-June. Acorns 

 ripe Sept.-Oct. 



Hybrids with Q. macrocarpa have been observed 

 in Illinois; with Q. minor, from Illinois to Virginia 

 and South Carolina, and with Q. Prtnus, near Wash- 

 ington, D. C., and New York. 



14. Quercus minor (Marsh.) Sarg. Post or Iron Oak. (Fig. 1241.) 



Quercus alba minor Marsh. Arb. Am. 120. 1785. 

 Quercus stellata Wang. Amer. 78. pi. 6. f. 75. 1787. 

 Q. obtusiloba Michx. Hist. Chen. Am. i. pi. i. 1801. 

 Quercus minor Sargent, Card. & For. 2: 471. 1889. 

 A tree, with rough gray bark, or sometimes a 

 shrub; maximum height about 100 and trunk 

 diameter 4. Leaves broadly obovate in out- 

 line, deeply lyrate-pinnatifid into 3-7 broad 

 rounded often deeply undulate or toothed lobes, 

 when mature firm, glabrous, dark green and 

 shining above, brown-tomentulose beneath, 5'- 

 8' long, 4 / -6 / wide or smaller; petioles stout, 

 J^'-i' long; fruit maturing the first season, 

 nearly or quite sessile; styles short; cup hemi- 

 spheric, 6 // -8 // broad, base narrowed, its bracts 

 lanceolate, subacute, slightly squarrose; acorn 

 ovoid, 6 // -io // high, 2-3 times as long as the cup- 

 In dry soil, Massachusetts to southern New York, 

 Michigan, Florida and Texas. Wood hard, close- 

 grained, very durable, brown; weight per cubic foot 

 52 Ibs. May-June. Acorns ripe Sept.-Oct. 



