138 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



3. Castanea neglecta Dode. 



With the preceding species near Upper Marlboro. June. The Upper Marlboro 

 specimens have the leaves of C. dentata and the inflorescence of C. pumila; probably 

 they represent a hybrid between those species. 



3. QTJERCTIS L. Oak. 



Leaves entire, linear to oblong-lanceolate. 

 Leaves linear-lanceolate; cup saucer-shaped, 8-12 mm. broad; acorn about 10 mm. 



liigli 1. Q. pheUos. 



Leaves oblong-lanceolate; cup hemispheric or nearly so, 10-15 mm. broad; acorn 



15 mm. high or smaller 2. Q. imbricaria. 



Leaves few-toothed to deeply lobed. 



Leaves very broad toward the apex, 3 or 5-lobed, abruptly contracted toward the 



base; cup hemispheric, 10-15 mm. broad; acorn ovoid 3. Q. marilandica. 



Leaves broadest at or near the middle, variously lobed or toothed, not abruptly 

 contracted toward the base. 

 Leaves more or less deeply lobed, the lobes bristle-pointed. Acorns ovoid, bitter. 

 Black or red oaks. 

 Leaves glabrous or with tomentum only in the axils of the veins beneath. 

 Leaves with asymmetric lobes. 

 Leaves narrowly oblong or oblanceolate; cup hemispheric or nearly so, 



about 15 mm. broad la. Q. heterophylla. 



Leaves of a broader type; cup about 20 mm. broad 2a. Q. leana. 



Leaves with more or less symmetric lobes. 

 Average leaves 10 cm. long or less, the basal lobes small, triangular. Cup 

 saucer-shaped, 10 mm. broad; lowermost branches pendent; leaves 



brown in autumn 4. Q. palustris. 



Average leaves 15 cm. long or more, variously lobed, the sinuses broad. 

 Lateral lobes of the leaves commonly simple, with few teeth, forming 

 an angle of 45° with the midrib; cup saucer-shaped, 2.5 cm. broad 



or more. Leaves red-brown in autunm 5. Q. maxima. 



Lateral lobes commonly .3-cleft, with accessory teeth, the primary lobes 

 forming an angle of about 60° with the midrib; cup turbinate or 

 hemispheric, 2 cm. broad or more. 

 Buds reddish brown, sparingly pubescent; leaves scarlet in autumn. 



6. Q. coccinea. 

 Buds densely grayish-pubescent; leaves brown in autumn. 



8. Q. velutina. 

 Leaves pubescent or tomentulose beneath. 

 Average leaves about 7 cm. long, commonly 5-lobed; cup 10 mm. broad, 

 turbinate. Lobes simple or nearly so, broadly triangular, the basal 



ones very short or wanting; acorn globose-ovoid 7. Q. ilieifolia. 



Average leaves 12 cm. long or more; cup 15 mm. broad or more.turbinate. 

 Buds densely grayish-pubescent; leaves more or less deeply 7-lobed, the 

 lateral lobes broad; acorn ovoid; leaves brown in autumn. 



8. Q. velutina. 



Buds sparingly pubescent, red-brown; leaves more or less deeply 3-13- 

 lobed, the lobes commonly simple, falcate, the base rounded; acorn 



globose-ovoid; leaves scarlet in autumn 9. Q. rubra. 



Leaves varying from serrate to deeply lobed, the lobes not bristle-tipped (at 



most acute). 



Leaves more or less deeply lobed (sometimes toothed in no. 11). WnrrE oaks. 



Leaves 20 cm. long or larger, obovate-oblong, more or less deeply 13-15-lobed, 



the lobes oblong. Cup hemispheric, 20 mm. broad; acorn oblong; leaves 



red-brown in autumn 10. Q. saulii. 



