348 FAGACEAE 



bearing a few fertile flowers at the base : calyx-lobes broadly ovate : fruiting involucre bur- 

 like, 1-2 cm. in diameter, the rigid spines comparatively few ; nut solitary, 1.5-2 cm. long. 

 On sand hills and in barrens, Georgia and Florida to Louisiana. Early spring. Chinquapin. 



2. Castanea pumila (L. ) Mill. A shrub or tree, reaching a maximum height of 16 

 m., with a trunk diameter of 1 m. Trunk clothed with a smooth l)ark : leaf -blades oblong or 

 obovate, acute or rounded at the apex, sinuate-toothed, glaljrous above, densely white- 

 tomentose beneath, the lateral nerves in 14-20 pairs, quite regularly disposed ; petioles 3-10 

 mm. long : staminate aments more or less spreading, 5-20 cm. long, continuous, sometimes 

 bearing several fertile flowers at the base : calyx-lobes ovate or oblong,, obtuse : fruiting in- 

 volucre subglobose, 3-4 cm. in diameter, the rigid spines densely disposed ; nuts ovoid, 

 1-1.5 cm. long, solitary or rarely 2 in a bur, shining, nearly terete. 



In sandy soil, New Jersey to Indiana, Florida and Texas. May and June. Chinquapin. 



3. Castanea dentata (Marsh. ) Borkh. A forest tree, reaching a maximum height of 

 about 30 m., with a trunk diameter of about 4 m. Trunk clothed with a longitudinally fur- 

 rowed bark : leaf-blades narrowly elliptic, elliptic-lanceolate or obiong-lanceolate, rarely 

 tending to oblanceolate, 10-30 cm. long, acuminate, coarsely and sharply serrate, dark- 

 green and shining above, paler beneath, glabrous on both sides ; petioles 1-2.5 cm. long : 

 staminate aments nearly continuous, 15-30 cm. long, white : calyx-lobes ovate or oblong- 

 ovate, obtuse : fruiting involucre globular, 5-7 cm. in diameter, thickly beset with rigid 

 spines ; nuts 2, 3 or 5, or rarely 1 in a bur, ovoid, 2-2.5 cm. long, nearly terete, or usually 

 flattened, at least on one side, appressed-pubescent especially near the apex. 



Chiefly in rich woods, Maine to Ontario and Michigan, Georgia and Alabama. June and July. 

 Chestnut, American Chestnut. 



3. QUERCUS L. 



Shrubs or trees, sometimes evergreen, with a hard, coarse-grained wood, all pervaded 

 by an astringent principle. Leaf-blades entire, toothed, or lobed, very variable in shape, 

 leathery, or firm-membranous, the lateral nerves often prolonged into slender bristles. 

 Staminate aments elongated, drooping, clustered. Calyx campanulate, 4-7-lobed, sub- 

 tended by caducous bracts. Stamens 6-12 : filaments filiform. Pistillate flowers solitary 

 or several together. Calyx often urn-shaped. Ovary usually 3-celled. Styles short, 

 usually 3. Ovules 2 in each cavity, but rarely more than 1 in each pistil maturing. Fruit 

 an acorn, consisting of a leathery 1-seeded nut subtended by or nearly enclosed in the 

 accrescent involucre (cup). Cotyledons half-terete. The plants flower in the spring and 

 mature their fruit in the fall of the first or second year. There are many natural hybrids. 



Leaf-blades or their lobes bristle-tipped : styles elongated : nuts oftenipubescent within. 

 A. Fruit maturing the second season : main stems erect or ascending, 

 a. Leaves deciduous, sometimes slightly persistent in the far south. 



Leaf-blades entire, little or not at all" dilated at the apex, never lobed ex- 

 cept on shoots, sometimes with 1 or few teeth near the apex. 

 Lower surface of the leaf-blades glabrous. 

 Cup of the acorn very flat. 



Leaf-blades acute, linear-oblong to narrowly elliptic or broadest 



slightly above or below the middle. 1- Q- Phellos. 



Leaf-blades blunt, oblong or cuneate. 2. Q. hyhnda.^ 



Cup of the acorn with a manifest and constricted base. 3. Q. laurifoha. 



Lower surface of the leaf-blades pubescent. 



Leaf-blades brown-tomentose beneath : cup of acorn hemispheric. 4. Q. vnbncana. 

 Leaf-blades gniy-tomentose beneath : cup of acorn saucer-shaped. 5. Q. brevlfolia. 

 Leaf-blades dilated near the apex, lobed to pinnatifid. 



Leaf-blades broadened upward, 3-lobed near the apex, occasionally 

 with several smaller lobes below. 

 Cup of the acorn sauier-shaped or cup-shaped: leaf-blades spatu- 

 late, glabrous. 

 Acorns les-s than 10 mm. long ; cup deep ; saucer-shaped : leaf- 

 blades thin. 6. Q. vucrocarya. 

 Acorns over 15 mm. long ; cup shallowly saucer-shaped : leaf- 

 blades thick. 7. Q. mgra. 

 Cup of the acorn hemispheric : leaf-blades obovate, brown-tomentose 



beneath. 8. Q. Marylandica. 



Leaf-blades pinnatifid or pinnately lobed. 



* Leaf-blades green and glabrous on both sides. 

 t Cup of the acorn saucer-shaped. 

 Cup less than IS mm. wide. 

 , Acorns or luits little if at all longer than thick. 



Petioles over 2 cm. long : leaf-blades with 5-7 lobes. 9. Q. palustns. 



Petioles less than 2 cm. long : leaf-blades with 3-5 lobes. 10. Q. Georgiana. 

 Acorns or nuts markedly longer than thick. 11. Q. Schneckii. 



Cup over 18 mm. wide. 



X Inner scales of the cup not inflexed. 



Leaf-blades with acute narrow sinuses ; lobes usually 



tapering to the apex. 12. Q- rubra. 



