454 CUPULIFERiE. (oak FAMILY.) 



full-grown trees, bright grocn, shining above, turning red in autumn, dcei)ly 

 ])innatilid, the lobes divergent and s])ariugly cut-toothed; acorns G"-9'' long, 

 the kernel and the scar in the cup whitish or yellowish ; bark of the trunk gray, 

 the interior reddish. — Moist or dry soil : common. 



Var. tinctdl'ia. (Qlkkcitro.v, Yellow-b-vukki), or Bl.vck Oak. (Q. 

 tinctoria, B(ti1nim.) Leaves, especially on young trees, often less deeply pinnat- 

 itid, sometimes barely sinuate, more menibianaceous, commonly retaining some 

 pubescence on the lower surface, turning brownish, orange, or dull red in au- 

 tumn ; bark of trunk darker-colored and rougher on the surface, thicker, and 

 internally orange, much more valuable for the tanner and dyer; cup sometimes 

 less top-shaped, rather hemispherical with a conical base, the scar inside orange- 

 colored, the kernel yellowish. But the shape of the acorn-cup and the charac- 

 ter of the bark do not always coincide : and in the figure of the younger Mi- 

 chaux, and in one of the two by the elder, the cup is just that of true coecinea. 

 The foliage, in general, approaches that of Q. rubra. — Rich and poor soil. 



Var. ambigua. (Viiiw 0.\k.) (Q. ambigua, or borealis, Miclix. f.) 

 Found along our northeastern borders to Lake Champlain and nortlnvaid, fig- 

 ured and briefly characterized as with the foliage of Q. rubra and the fruit of 

 Q. coecinea. The acorn in rising more out of the cup, also approaches the 

 former. The Oak of Lake Superior, with " wood better than that Of Q. rubra " 

 (Dr. lioWitis) has cup and acorn still more like this last. 



A hybrid Q. coccinea-ilicifolia is found by Dr. Robhins at Northbridge, 

 S. Massachusetts. 



15. Q. rvibra, L. (Red Oak.) Cup saucer-sluiped or flat, with a narrow 

 raised border (9"- 12" in diameter), of rather fine closely appressed scales, sessile 

 or on a very short and abrupt narrow stalk or neck, veri/ much shorter than the 

 obloiifj-oroid or tHipaoidal. acorn, which is 1' or less in length; leaves rather thin, 

 moderately (rarely very deeply) pinnatitid, turning dark red after frost; bark 

 of trunk dark gray, smuothisli. — Common both in rich and poor soil. — Tim 

 ber coarse and poor. In Illinois and southward occurs a form with a deeper cup, 

 more or less conical at ba.sc. 



Var. runcinkta, Engelm. Leaves with less deep and more ascending 

 lobes; fruit nearly half smaller; acorn 7" -9" long by 6" broad; cup with a 

 convex or obscurely top-shiiped base : approaches the next therefore in fruit, 

 but not in foliage. St. Louis, in company with Q. rubra, palustiis and imbri- 

 caria ; ])rol)aI)ly a hybrid. 



16. Q. pallistris, I)u Roi. (Swamp Spanish, or Pin Oak.) Ciipjl'it- 

 saucer-shnprd, sometimes contracted into a short scaly base or stalk ; fine-.scaled 

 (5"-7"l)road), fci-i/ viuch shorter than the ovokl-f/lobose acorn, which is .'j"-7" 

 long; leaves deeply pinnatifid with divergent lobes and broad rounded sinuses. 

 — Low grounds : rather common. — A middle-sized tree : timber accounted 

 better than of the last. 



2. CASTANEA, Tourn. Chestnut. 



Sterile flowers interruiitcdly clustered in long and naked cylindrical catkins : 

 calyx mostly 6-parted : stamens 8-20: filaments slender: anthers 2-celled. 



