94 CUPULIFEILE. Quercus. 



leaves. Very large trees, or sometimes shrubs. Engelmann, Trans. St. Louis 

 Acad. iii. 372. 



A large and difficult genus of about 250 species, distributed throughout the temperate and 

 warm regions of the northern hemisphere, especially abundant in Eastern Asia and in Mexico. Of 

 the 40 species found within the limits of the United States, 25 are limited to the region eastward 

 of the Rocky Mountains. A single species (Q. undtilata) is found in Colorado and Utah, ranging 

 also into S. California, all the other California!! forms, excepting Q. obloinjifolm of the southern 

 border, being peculiar to the Western Coast. One other species (Q. Emoryi) belongs to Arizona 

 and New Mexico, but does not enter California. The wood of the genus is mostly hard and 

 durable, and most valuable lor its economic uses. The bark also, from the amount of tannin 

 which it contains, is extensively used in the manufacture of leather. 



Staminate aments pendulous, below the pistillate flowers : filaments not 



longer than the anthers : stigmas dilated. 

 Abortive ovules at the base or side of the seed : stamens 6 to 8: stigmas 



subsessile: bark light-colored. 

 Acorns glabrous within, maturing the first year. 

 Leaves deciduous : large trees, with large acorns. 



Branches slender, glabrous : leaves deeply lobed, 4 inches long or 



less: buds oval, small: nut long-conical. 1. Q. LOBATA. 



Branchlets thicker, pubescent : leaves larger, rougher : buds 



large, lanceolate, tomentose : riut ovate. 2. Q. GARRY AN A. 



Branchlets pubescent : leaves less lobed, 1 or 2 inches long : 



buds small, oval, slightly pubescent: nut long-oblong. 3. Q. DOUGLASII. 



Leaves deciduous, small, deeply lobed : a shrub with slightly pu- 

 bescent branchlets : buds oval, subpubescent : nut oval. 4. Q. BREWEKI. 

 Leaves persistent, coriaceous, small. 



Shrub : leaves broadly oval, 1 inch long, spinoselylobed-dentate : 



cup 3 or 4 lines wide : nut elongated, slender. 5. Q. TJNDULATA. 



Shrub or small tree : leaves oblong, to 1 inch long, entire or 



sinuate or spinose-toothed : cup 4 to 10 lines wide : nut oval. 6. Q. DUMOSA. 

 Small tree : leaves oblong, 1 or 2 inches long, entire or with few 



blunt teeth : nut oblong. 7. Q. OBLONGIFOLIA. 



Acorns biennial, pubescent or (in n. 10) tomentose within : leaves 



persistent, coriaceous. 



Large tree or shrub : leaves oblong, 1 or 2 inches long, entire or 

 sharply-toothed : cup yellow-tomentose, often very thick, hemi- 

 spherical : nut oval, obtuse. 8. Q. CHRYSOLEPIS. 

 Tree : leaves oblong-lanceolate, 2 or 3 inches long, crenate-dentate, 



strongly ribbed : nut ovate, in a shallow cup. 9. Q. TOMENTELI.A. 



Shrub : leaves round-oval, rigid, 1 inch long or less, spinose-den- 



tate : cup turbinate. 10. Q. PALMERI. 



Abortive ovules at top of the seed : anthers 4 or 5 : styles long : nuts 

 tomentose within : bark dark : leaf- lobes setaceously mucro- 

 nate. 

 Acorns annual : leaves subpersistent. 



Large tree or shrub : leaves oblong to orbicular, 2 or 3 inches long, 

 sinuately spinose-deutate : cup turbinate : nut elongated, 

 acute. 11. Q. AGRIFOLIA. 



Acorns biennial. 



Tree or shrub : leaves persistent, strongly reticulated, dark green 

 and shining, entire to spinosely sinuate-lobed ; petioles short : 

 cup turbinate, very deep : nut slender, acute. 12. Q. WISLIZENI. 



Tree or shrub : leaves deciduous, pinnatifid-lobed ; petioles long : 



cup hemispherical : nut oblong, obtuse. 13. Q. KELLOGGII. 



Aments erect, pistillate at base or wholly staminate : filaments elongated : 



stigmas linear : fruit biennial : leaves persistent. 14. Q. DENSIFLORA. 



1 . Staminate aments naked, from last year's buds or from, the lower part of 

 this year's shoots, pendulous ; filaments not lonf/er than the anthers ; pol- 

 len tarye (.015 .020 lines in diameter): pistillate flowers above the 

 staminate aments, from the axils of young leaves; stigmas dilated. 

 LEPIDOBALANUS, EndL 



