328 CUPULIFER.E. 



cles or sessile on a rachis. Involucre 1 -flowered, consisting of 

 many imbricate scales, which in fruit become an indurated 

 cup (cupule), surrounding the base of the ovoid or roundish 

 1 -seeded nut or acorn. 



* Fruit biennial, subsessik. 

 f Leaves entire. . 



1 . Q. Pkellos Linn. : leaves deciduous, linear-lanceolate, tapering at 

 each end, very entire, smooth, mucronate ; acorn nearly round. 



Low swampy forests. Suffolk county, N. Y. Torr. S. to Flor. W. to Ark. 

 April, May. A tree 30 to 60 feet high, generally straight and slender. Leaves 

 when young of a light-green color and dentate. Acorn small, nearly round. 

 The timber is of little use. Willow Oak. 



2. Q. imbricaria Mich. : leaves deciduous, oblong, acute at each end, 

 mucronate, very entire, shining, pubescent beneath ; cup shallow ; scales 

 broad-ovate ; acorn subglobose. 



Banks of rivers in mountainous regions. Penn. to Flor. W. to Miss. June. 

 A tree 4050 feet high, with numerous irregular branches. Acorn small, nearly 

 spherical, in a flat nearly sessile cup. The wood splits easily, and is used in the 

 Western States for shingles. Shingle Oak. 



ff Leaves toothed or lobed. 



3. Q. heterophyUa Mich. : leaves on long petioles, ovate-lanceolate or 

 oblong, entire or coarsely toothed ; cup hemispheric ; acorn subglobose. 



Banks of the Delaware. Penn. May. Pj. According to Pursh there is 

 only one individual of this species known, which grows near Philadelphia. He 

 suggests that it may be a hybrid. It is figured and described by Michaux in his 

 Sylva Americana. Various-leaved Oak. 



4. Q. aqnatica Walt. : leaves obovate-wedgeform, smooth, very entire, 

 obscurely 3-lobed at the end, with the middle lobe largest ; cup hemispheric ; 

 acorn subglobose. Q. nigra Linn. 



Swamps. Md. to Flor. W. to Ark. May. A tree 3040 feet high. Leaves 

 very variable. Cup shallow. Acorn rather small, roundish. It resembles Q. 

 laurifolia. Its timber is of no value. Water Oak. 



5. Q. IrUobaLinn: leaves oblong- wedgeform, acute at the base, somewhat 

 3-lobed at the end ; lobes equal, mucronate, tomentose beneath, middle one 

 longer ; cup'flat ; acorn depressed-globose. 



Pine barrens. N. J. to Geor. May. A tree 20 40 feet high, of rapid growth. 



Downy Black Oak. 



6. Q. nigra Wittd. : leaves coriaceous, wedgeform, subcordate at base, 

 dilated and retusely 3-lobed above, the lobes mucronate when young, rusty- 

 pulverulent beneath ; cup turbinate, with the scales obtuse and scarious ; 

 acorn short, ovoid. Q. ferruginea Mich. f. 



Sandy woods. Long Island. Torr. S. to Flor. May. A tree 10 30 feet 

 high, irregular in its growth, and covered with a thick rough black bark. The 

 wood is much esteemed for fuel ; but is seldom of sufficient size to be of any 

 value as timber. Barren Oak. Black Jack Oak. 



7. Q. tinctoria Bartram: leaves obovate-oblong, somewhat sinuate- 



