344 CORYLACEAE 



Staminate flowers without bractlets : pistillate flowers numerous in elongated aments : nuts small, 

 subtended by or inclosed in a bract. 

 Fruiting bracts flat, 3-lobed, the terminal lobe toothed. 1. Carpinus. 



Fruiting bracts bladder-like. 2. Cstrya. 



Staminate flowers with bractlets : pistillate flowers few, in heads : nuts large, in leaf-like 



involucres. 3. Corylus. 



1. CARPINUS L. 



Trees or rarely shrubs, with a heavy close-grained wood and a pale smooth bark. 

 Staminate aments relatively sliort, droopijig, solitary. Stamens 3-20, inserted on a broad 

 scale : filaments very short, branched at the summit : anther-sacs separate, pilose at the 

 apex. Pistillate aments terminal, lax, ascending : bracts accrescent, leafy, 3-lobed : pistils 

 2, at the base of a scale. Nut ovoid, flattened, sessile, ribbed, crowned by the remains of 

 the calyx, the outer coat thin, membranous, the inner thicker, bony. Seed solitary, 

 pendulous. The plants bloom in the spring. Hornbeam. Iron-wood. Blue Beech. 



1. Carpinus Carollniana Walt. A shrub or small tree, with a maximum height of 

 about 13 m. and a trunk diameter of 8 dm. Bark blue-gray : leaf -blades thinnish, oblong, 

 varying to ovate or ovate-lanceolate, or obovate, 3-14 cm. long, acute or acuminate, rather 

 finely and doubly serrate (the larger teeth sometimes flaring), glabrous above, more or less 

 pubescent on the nerves beneath and tufted in the axils ; petioles slender, 3-17 mm. long : 

 staminate aments drooping, 2-5 cm. long, their scales spreading, triangular-ovate, 3 mm. 

 long, acute, ciliate : anthers pubescent at the tips: pistillate aments inconspicuous, 1-1.5 

 cm. long, their bracts lanceolate, 6-7 mm. long, acuminate, ciliate, accrescent : fruiting 

 aments 3-10 cm. long, their bracts hastate, 2-3 cm. long, the lobes entire or toothed, the 

 lateral ones usually only on one side : nut ovoid, 5-6 mm. long, slightly flattened, ribbed. 



In moist woods and swampy places, Nova Scotia to Minnesota, Nebraska, Florida and Texas 



2. OSTRYA Scop. 



Trees, with a hard close-grained wood, a scaly bark and slender terete branches. Stam- 

 inate aments clustered, drooping : bracts very broad, bearing 3-14 stamens, which are 

 crowded on a receptacle without bractlets : filaments very short, forked at the tips : anther- 

 sacs pilose towards the ends, separated. Pistillate aments solitary and terminal on leafy 

 branchlets : bractlets subtending 2 flowers : pistils surrounded by a pilose involucre : calyx- 

 limb denticulate. Nut ovoid, flattened, obscurely ribbed, crowned by the remains of the 

 calyx, with a double pericarp, the outer coat thin, membranous, the inner thicker, bony. 

 The plants bloom in the spring. Lever-wood. Hop-hoknbeam. Iron-wood. 



1. Ostrya Virginiana (Mill.) Willd. A shrub'or tree, reaching a maximum height 

 of 18 m., with a trunk diameter of about 6 dm. Bark dry, scaly : leaf-blades oblong, 

 elliptic or oval, varying towards ovate or obovate, 3-13 cm. long, acute or acuminate, 

 finely and doubly serrate, rounded, subcordate and inequilateral at the base, dark green 

 and slightly pubescent or glabrate above, more densely pubescent beneath ; petioles 2-8 

 mm. long: staminate aments drooping, 3-8 cm. long: scales orbicular-obovate, 3.5mm. 

 long, delicately nerved, ciliate, the acuminate apex colored : anthers villous at the top : 

 pistillate aments shorter than tlie staminate, their scales lanceolate or ovate-lanceolate, 3 

 mm. long, ciliate, the tip of the acumination colore<l, the bracts developing into pubescent 

 nerved bladdery sacs, which are collected into a drooping oblong spike at maturity : nuts 

 ovoid, 6-7 mm. long, faintly ribbed. 



In dry woods and on hillsides, Cape Breton Island to South Dakota, Florida and Texas. 



3. CORYLUS L. 



Shrubs or trees, with much branched stems. Staminate aments elongated, pendulous, 

 solitary or clustered : bracts bearing 4-8 stamens which are inserted on a pilose receptaclci 

 accompanied by 2 bractlets : filaments very short, forked at the top : 'anther-sacs pilose at the 

 apex, separated. Pistillate aments inconspicuous, clustered at tlie tips of twigs of the sea- 

 son : each bract subtending an incompletely 2-celled ovary and 2 bractlets : nuts as broad 

 as long or nearly so, sometimes flattened, enclosed in an involucre formed of the nearly 

 distinct or united bractlets. Hazel-nut. 



Mature bractlets united, prolonged into a narrow beak. 1. C. rostrata. 



Mature bractlets distinct, leaf-like, incised. 2. C. Americana. 



