328 CUPULIFER^. 



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. 



* Jpyuit biennial, subsessile. 

 t Leaves entire. 



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

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



Low swampy forests. Suffolfc 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. imhricaria 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 40 — 50 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. heUrophylla Mich. : leaves on long petioles, ovate-lanceolate or 

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



Banks of the Delaware. Penn. May. T7. — 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. aquatica Walt. : leaves obovate-wedgeform, smooth, very entire, 

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

 acorn subglobose. Q. nigj'a Linn. 



Swamps. Md. to Flor. W. to Ark. May. — A tree 30 — 40 feet high. Leaves 

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

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



5. Q. triloba Linn : leaves oblong- wedge form, 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. 



Doumy Black Oak. 



6. Q. nigra Willd. : 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. ferrughiea 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 tin^toria Bartram: leaves obovate-oblong, somewhat sinuate- 



