CUPULIFEU^. 205 



ovary tipped with 2 long stigmas, and surrounded by a tiibular- 

 bractlet which, in fruit, becomes a greenish-white inflated bag', 

 having the sinall nut in the bottom, 

 6. Oarpi'iins. Sterile flowers In drooping catkins. Calyx wanting. 

 Stamens several under each bract ; no bractlets. Fertile Bowers 

 much as in Ostrya, but the bractlets surrounding the ovaries are 

 not tubular but open, and in fruit become leaf -like, one on each side 

 of the small nut. 



1. ailERCirs, L. Oak. 



* Acorns ripening the first year, and therefore borne on the new shoots. 

 Lobes or teeth of tite leaves not bristle-pointed. 



1. Q. alba, L. (White Oak.) A large tree. Leaves 

 (when mature) smooth, bright green above, ivhitish beneath, 

 obliquely cut into few or several oblong entire lobes. The 

 oblong nut much larger than the saucer-shaped rough 

 oupule. — Eich woods., 



2. Q. maeroear'pa, Miohx._ (Bur Oak. Mossy -cup 

 White Oak.) A medium-sized tree. Leaves deejjly lohed, 

 smooth above, pale or downy beneath. Acorn broadly 

 ovoid , half or altoijetlier covered by the deep cup, the upper 

 scales of which taper into bristly points, mahing a fringed 

 border. Cup varying greatly in size, often very large., — 

 Eich soil. , 



3. Q. bi'eolor, WiUd. (Swamp White Oak.) A tall tree. 

 Leaves sinuate-toothed, bu;fc hardly lobed, wedge-shaped at the 

 base, downy or hoary beneath, the main veins 6-8 pairs. 

 Oup nearly hemispherical, about half as long as the oblong- 

 ovoid acorn, sometimes with a fringed border. Peduncles in 

 fruit longer than tlve petiole..— Ijowf grounds. 



4. Q. Pri'nus, L. (Chestnut Oak.) A small tree. Leaves 

 minutely downy beneath, the main veins 10-16 pairs, sinu- 

 ate-toothed, acute or obtuse at the base. Peduncle shorter 

 than the petiole. Cup hemispherical; acorn as iu the last. 

 — Lake Erie coast. 



Var. hu'milis. Marsh, [Q. prinoidea, Willd., in Macoun's 

 CatalogTue) is much more abundant with us than the species 

 itself. It has the characters of the species, but is a shrub, 

 - 2-4 feet high. !Fruit sessile or nearly so. 



