CUPUi.lFEK«. 205 



ovary tipped with 2 long stigmas, and surrounded by a tubular 

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

 having the small nut in the bottom. 

 6. Carpi'nns. Sterile flowers in drooping catkins. Calyx wanting. 

 Stamens several under each bract ; no bractlets. Fertile flowers 

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

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

 of the small nut. 



1. (tnSRCVS, L. Oak. 



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

 Lobes or teeth of the leaves not bristle-pointed. 



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

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

 obliquely cut into few or several oblong entire lobes. The 

 oblong nut much larger than the sauoer-shaped rough 

 cupule. — Rich woods. 



2. Q. maeroeap'pa, Miohx. (Bub Oak. Mossy -cup 

 White Oak.) A medium-sized tree.. Leaves deeply lobed, 

 smooth above, pale or downy beneath. Acorn broadly 

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

 scales of which taper into bristly points, making a fringed 

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

 Eich soil. 



3. Q. bi'eolOF, WiUd. (Swamp White Oak.) AtaUtree. 

 Leaves sinuate-toothed, but hardly lobed, wedge-shaped at the 

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

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

 ovoid acorn, sometimes with a fringed border. Peduncles in 

 fruit longer than the petiole. — Low 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 in the last. 

 — Lake Erie coast 



Var. hu'milis, Marsh, {Q. prinoides, Willd., in Macoun's 

 Catalogue) 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. 



