52 ■ ELEMENTS OF BOTANY. 



II. CASTANEA. 



Trees or shrubs with rough, gray, rather close bark ; leaves 

 straight-veined, undivided, prominently toothed : flowers ap- 

 pearing later than the leaves ; staminate aments erect or 

 spreading, loosely flowered, flowers several in the axil of each 

 bract, calyx 4-6-parted, stamens 8-16 ; pistillate flowers at 

 the base of the staminate anient or in small separate clusters, 

 usually 3 in each involucre ; ovary 4-celled, surrounded by 

 5-12 abortive stamens, fruit a 1-celled nut enclosed in the 

 greatly enlarged and very prickly involucre. 



1. C. DENTATA (Maush) Berkli. American Chestnut. A large 

 tree, bark somewhat rough, and splittiiig into longitudinal plates ; 

 leaves oblong-lanceolate, acuminate at the apex, usually acute at the 

 base, coarsely and sharply serrate with ascending teeth, glabrous, 

 dark green above, lighter below ; petioles stout, short ; staminate 

 aments erect, 6-10 in. long ; nuts usually 3 in each burr. February- 

 March. Rich soil in the upper districts. Rarely found on soils con- 

 taining nmch lime. 



2. C. PUMILA (L.) Willd. Chinquapin. A small tree or shrub ; 

 leaves oblong, acute or obtuse at both ends, serrate with divergent 

 teeth, dark green and smooth above, white-woolly below ; nuts soli- 

 tary, nearly globular. March-April. Common southward in rich 

 woods. 



III. QUERCUS. 



Trees or shrubs, with entire, serrate or lobed leaves which 

 are often persistent ; staminate flowers in slender aments, 

 each subtended by quickly deciduous bracts, and consisting 

 of 3-12 stamens enclosed by a 4-8-parted perianth, often con- 

 taining an abortive ovary ; pistillate flowers solitary or in 

 small clusters, each consisting of a 3-celled ovary with 2 ovules 

 in each cell, though rarely more than 1 ovule matures ; styles 

 short, erect or recurved ; pistillate flowers surrounded by a 

 scaly involucre which at maturity becomes a cup enclosing 

 the base of the fruit or sometimes a large part of it; fruit an 

 ovate or subglobose, 1-seeded, thin-shelled nut (acorn). 



A. Fruit biennial ; leaves entire or with bristle-pointed 

 lobes. 



