QUERCUS 79 



3. Qj_ lyrata Walt. Overcup Oak . A tree up to 35 m. high, 

 with a trunk diameter of 9-12 dm. ;bark gray; twigs buff, pubes- 

 cent, becoming glabrate; buds 3 mm. long, ovoid -globose, the 

 scales light chestnut-brown, somewhat tomentose; acorn 1. 2-2. 5 

 cm. long, the cup subglobose, pubescent, nearly covering the de- 

 pressed nut. Bottomlands, mostly in the coastal plain, Texas and 

 Florida to New Jersey, up the Mississippi Valley to Indiana and 

 Missouri (Fig. 66). 



4. Q. macrocarpa Michx. Bur Oak . A tree 15-40 m, high, 

 1-2 m. in diameter, with gray flaky bark; buds ovoid or conical- 

 ovoid; twigs and buds gray-pubescent; acorn 1. 5-3. 5 cm. high, the 

 nut half-covered or rarely nearly covered by the fringed bur-like 

 cup. Bottomlands, New Brunswick to Manitoba, south to North 

 Carolina, Tennessee, and Texas; not in the coastal plain (Fig. 67). 



5. O^ bicolor Willd. Swamp White Oak . A tree 15-25 m. 

 high, 6-9 dm. in diameter, with flaky gray bark, exfoliating from 

 the branches; twigs straw-brown; buds 2-3 mm. long, subglobose 

 or ellipsoid, nearly or quite glabrous; stipule- scars lacking or in- 

 conspicuous; acorn 2-3 cm. long, the cup one-third to one-half 



as long as the nut. Bottomlands, Maine to Minnesota and Nebraska, 

 south to Georgia, Kentucky, and Oklahoma (Fig. 68 ). 



6. ^ michauxii Nutt. Basket Oak . Cow Oak . Swamp Chest - 

 nut Oak. ( Q. prinus of authors, not L. ). Tree 20-30 m. high, with 

 a trunk diameter of 6-9 dm. ;bark silvery-whitish; twigs olive or 

 brown; buds 6 mm. long, the scales red, puberulous; acorn ovoid- 

 cylindric, about 3 cm. long. Bottomlands and swamps, mostly in 

 the coastal plain, Texas to Florida and New Jersey, north in the 

 Mississippi Valley to Indiana and Missouri (Fig. 69 ). 



7. ^ muehlenbergii Engelm. Yellow Oak. Muhlenberg Oak . 

 Chinquapin Oak. A tree 15-25 m.high, 6-9 dm. in diameter, with 

 close thin gray bark, flaky when old; twigs orange-brown; buds 3 

 mm. long, ovoid or conical-ovoid, brown-puberulent or glabrous, 

 the scales often pale-margined; acorn globose or obovoid, 1. 2-2 

 cm. long, sessile or nearly so, the cup thin, enclosing half the 

 nut. Dry limestone slopes, Vermont and Minnesota, south to 

 Florida and Texas (Fig. 70). 



8. ^ prinus L. Chestnut Oak. Rock Oak (Q. montana Willd. ) 

 A tree 20-30 m. high, 1-2 m. in diameter, with thick and deeply 

 grooved bark; twigs brown; buds distinctly conical, 5-6 mm. long, 

 deep brown, dull, outer scales pale-margined; acorn 2. 5-3. 5cm. 

 long; ovoid, the cup thick. Dry woods, mostly on sandstone, Maine 

 to Indiana, south to Georgia and Mississippi; not in the coastal 



