6o6 



BETULACEAE. 



Vol. I. 



i. CARPINUS (Tourn.) L. Sp. PI. 998. 1753. 



Trees or shrubs, with smooth gray bark, furrowed and ridged stems and straight-veined 

 leaves, the primary veins terminating in the larger teeth. Aments expanding before the 

 leaves. Staminate aments linear-cylindric, sessile at the ends of short lateral branches of 

 the preceding season, their flowers solitary in the axil of each bract, consisting of 3-12 sta- 

 mens; filaments short, 2-cleft, each fork bearing an anther-sac. Pistillate flowers in small 

 terminal aments, 2 to each bract, consisting of a 2-celled ovary adnate to a calyx and sub- 

 tended by a flat persistent bractlet, which becomes much enlarged, foliaceous and lobed or 

 incised in fruit, the bracts deciduous ; style slender or almost none ; stigmas 2, subulate. Nut 

 small, ovoid, nerved, acute, borne at the base of the large bractlet. [The ancient name.] 



About 12 species, only the following American. Type species: Carpinus Betulus L. 



i. Carpinus caroliniana Walt. American Hornbeam. Blue Beech. Water-beech. 



Fig. 1490. 



Carpinus caroliniana Walt. Fl. Car. 236. 1788. 



A small tree, with slender terete gray twigs'; 

 maximum height about 40 , trunk diameter of 

 2j°. Leaves ovate-oblong, acute or acuminate 

 at the apex, sharply and doubly serrate all 

 around, rounded or subcordate at the base, 

 somewhat inequilateral, 2Y-4' long, i'-ii' wide, 

 green on both sides, glabrous above,- slightly 

 pubescent on the veins beneath, petioles very 

 slender, 4"-y" long; staminate aments i'-ii' 

 long, their bracts triangular-ovate, acuminate, 

 puberulent; anther-sacs villous at the summit; 

 bractlet of the pistillate flowers 3-lobed at the 

 base, firm-membranous, strongly veined and 

 about 1' long when mature, its middle lobe 

 lanceolate, acute, 2-4 times as long as the 

 lateral ones, incised-dentate on one side, often 

 nearly entire on the outer; nut 2" long. 



In moist woods and along streams, Nova Scotia 

 to Ontario and Minnesota, Kansas, Florida and 

 Texas. Wood very hard and strong, durable, light 

 brown ; weight per cubic foot 45 lbs. April-May, 

 the fruit ripe Aug.-Sept. Water-beech. Iron- 

 wood. 



2. OSTRYA (Micheli) Scop. Fl. Carn. 414. 1760. 



Trees similar to the Hornbeams, the primary veins of the leaves simple or forked, the 

 aments expanding with or before the leaves. Staminate aments sessile at the ends of 

 branchlets of the preceding season, their flowers as in Carpinus, solitary in the axil of each 

 bract; filaments 2-cleft. Pistillate aments small, terminal, erect, the flowers 2 to each bract, 

 subtended by a tubular, persistent bractlet which enlarges into a membranous, nerved, 

 bladder-like sac in fruit. Style slender; stigmas 2, subulate. Nut ovoid-oblong, com- 

 pres^d, smooth, sessile. Mature pistillate ament hop-like. [The ancient name.] 



Six species, the following, 2 in the southwest, 1 in Europe and Asia,_ 1 in Mexico, 1 Japanese. 

 Type species : Ostrya Ostrya (L.) MacM. 



1. Ostrya virginiana (Mill.) Willd. Hop- 

 hornbeam. Iron-wood. Fig. 1491. 



Carpinus virginiana Mill Gard. Diet. Ed. 8. 1768. 

 Ostrya virginica Willd. Sp. PI. 4: 469. 1803. 



A tree, with a maximum height of about 50°, 

 trunk diameter of 2°, twigs of the season pubescent. 

 Leaves ovate or oblong-ovate, the apex acuminate, 

 the base rounded or inequilateral, sharply and doubly 

 serrate, sparingly pubescent and green above, pubes- 

 cent or tomentose beneath, 2i'-4 long, i'-ij' wide; 

 petioles rarely more than 2" long; staminate aments 

 ii'-3' long, their bracts triangular-ovate, acuminate ; 

 anther-sacs villous at the summit; bractlet of each 

 fertile flower forming a sac 6"-8" long and 4"-$" 

 in diameter in fruit, acute, cuspidate, pubescent, vil- 

 lous near and at the base with bristly hairs, parellel- 

 veined and finely reticulated; nut 2i" long, com- 

 pressed, shining; ripe fertile aments erect or spread- 

 ing, i4'-2i' long, resembling hops. 



