478 CLPULiFEii.i:. (oak family.) 



Var. ambigua. Gray. (Gray Oak.) Found along our uortheasteru bor- 

 ders to Lake Chainplaiii and north-ward, figured and briefly characterized by 

 Michaux as with the foliage of Q. rubra and the fruit of Q. coccinea. It was 

 considered by Dr. Engelmann as a form of Q. rubra with cups hemispherical 

 or even turbinate. 



13. Q. palustris, Du Roi. (Swamp Spanish or Pin Oak.) Cup Jiat- 

 saucer-sluiped, sometimes contracted into a short scaly base or stalk, fine scaled 

 (5 - 7" broad), verij much shorter than the usually globose or depressed acorn, which 

 is 5 - 7" long ; leaves deeply pianatifid with divergent lobes and broad rounded 

 sinuses. — Low grounds; rather common, from Mass. to Del. and Md., west 

 to Minn., E. Kan., and Ark. 



■*~-i-2Iature leaves soft-downy beneath; cup saucer-shaped, ivith a somewhat 

 top-shaped base, about half the length of the fully developed small acorn. 



14. Q. falcata, Michx. (Spanish Oak.) Leaves grayish-downy or ful- 

 vous underneath, obtuse or rounded at base, 3 - 5-lobed above (sometimes entire) ; 



Ihe lobes prolonged, mostly narrow and more or less scythe-shaped, especially the 

 terminal one, entire or sparingly cut-toothed ; acorn globose, 4 - 5" long. — 

 Dry or sandy soil. Long Island to Fla., and from S. Ind. to Mo. and Tex. A 

 \arge or small tree, extremely variable in foliage ; bark excellent for tanning. 



15. Q. ilicifolia, Wang. (Bear or Black Scrub-Oak.) Dwarf (3 - 

 8° high), straggling; leaves (2-4' long) thickish, obovate, wedge-shaped at 

 lase, angularly about 5- (3 - 7-) lobed, ivhite-downy beneath ; lobes short and tri- 

 angular, spreading ; acorn ovoid, globular, 5 - 6" long. — Sandy barrens and 

 rocky hills, N. Eug. to Ohio and Ky. 



*t * Leaves entire or with afeiv teeth [or somewhat 3 - 5-lobed at the summit), coria- 

 ceous, commonly bristle-pointed ; acorns globular, small {not over 6''' long). 

 -r- Leaves thick, widening or often-much dilated upward and more or less sinuate 

 or some u-hat 3 -5-lobed ; acorns globular-ovoid. 



16. Q. aquatica, Walter. (Water-Oak.) Leaves glabrous and shining, 

 obovate-sputulate or narrowly wedgeform, with a long tapering base and an often 

 obscurely 3-lobed summit, varying to oblanceolate ; cup saucer-shaped or hemi- 

 spherical. — Wet grounds, around ponds, etc., Del. to the Gulf, and from Ky. 

 and Mo. to Tex. — Tree 30 - 40° high ; running into many varieties, especially 

 southward ; the leaves on seedlings and strong shoots often incised or sinuate- 

 pinnatifid ; then mostly bristle-pointed. 



17. Q. nigra, L. (Black-Jack or Barren Oak.) T^eaves broadly wedge- 

 shaped, but sometimes rounded or obscurely cordate at the base, widely dilated 

 and somewhat 3-lobed (rarely 5-lobed) at the summit, occasionally with one or 

 two lateral conspicuously bristle-tipped lobes or teeth, rusty-pubescent beneath, 

 shining above, large (4 - 9' long) ; cup top-shaped, coarse-scaly ; ac<jrn short- 

 ovoid. — Dry sandy barrens, or heavy clay soil, Long Island to S. Minn., E. 

 Neb., and southward. A small tree (sometimes 30-40° high), of little value. 



•i- -«- Leaves not dilated upward, generally entire; acorn globose. 



18. Q. imbricaria, Michx. (Laurel or Shingle Oak.) Leaves Ian 

 ceolate-oblong , thickish, smooth, and shining above, downy underneath, the down 

 commonly persistent ; cup between saucer-shaped and top-shaped. — Rich 

 woodlands, Penn. to Ga., west to S. Wise, Iowa, E. Neb., and N. Ark. — 



