2. OSTRYA Scop. Hop Hornbeam.

Trees, with scaly bark, heavy hard strong close-grained wood, and acute elongated winter-buds formed in early summer and covered by numerous imbricated scales, the inner lengthening after the opening of the bud. Leaves open and concave in the bud; petioles slender, nearly terete, hairy; stipules strap-shaped to oblong-obovate. Flowers: staminate in long clustered sessile or short-stalked aments developed in early summer from lateral buds near the ends of short lateral branchlets of the year and coated while young with hoary tomentum, naked and conspicuous during the winter, and composed of 3—14 stamens crowded on a pilose receptacle adnate to the base of an ovate concave scale rounded and abruptly short-pointed at the apex, ciliate on the margins, longer than the stamens; filaments short, 2-branched, each branch bearing a 1-celled half-anther hairy at the apex; pistillate in erect lax aments terminal on short leafy branches of the year, in pairs at the base of an elongated ovate acute leaf-like ciliate scale persistent until midsummer, each flower inclosed in a hairy sack-like involucre formed by the union of a bract and 2 bractlets; calyx adnate to the ovary, denticulate on the free narrow border. Nut ovoid, acute, flattened, obscurely longitudinally ribbed, crowned with the remnants of the calyx, marked at the narrow base by a small circular pale scar, inclosed in the much enlarged pale membranaceous conspicuously longitudinally veined reticulate-venulose involucres of the flower, short, pointed and hairy at the apex, hirsute at the base, with sharp rigid stinging hairs, imbricated into a short strobile fully grown at midsummer, and suspended on a slender hairy stem.

Ostrya is widely distributed in the northern hemisphere from Nova Scotia to Texas, northern Arizona, and to the highlands of southern Mexico and Guatemala in the New World, and through southern Europe and southwestern Asia, and in northern Japan and on the Island of Quelpart in the Old World. Of the four species now recognized two are North American.

Ostrya is the classical name of the Hop Hornbeam.

CONSPECTUS OF THE NORTH AMERICAN SPECIES.

Leaves oblong-lanceolate, acuminate or acute at apex.1. [O. virginiana] (A, C). Leaves elliptic or obovate, acute or rounded at apex.2. [O. Knowltonii] (F).

1. [Ostrya virginiana] K. Koch. Hop Hornbeam. Ironwood.

Leaves oblong-lanceolate, gradually narrowed into a long slender point or acute at apex, narrowed and rounded, cordate, or wedge-shaped at the often unequal base, sharply serrate, with slender incurved callous teeth terminating at first in tufts of caducous hairs, when they unfold light bronze-green, glabrous above and coated below on the midrib and primary veins with long pale hairs, at maturity thin and extremely tough, dark dull yellow-green above, light yellow-green and furnished with conspicuous tufts of pale hairs in the axils of the veins below, 3′—5′ long, 1½′—2′ wide, with a slender midrib impressed and puberulous above, light yellow and pubescent below, and numerous slender veins forked near the margins; turning clear yellow before falling in the autumn; petioles hairy about ¼′ long; stipules rounded and often short-pointed at apex, ciliate on the margins with long pale hairs, hairy on the back, about ½′ long and ⅛′ wide. Flowers: staminate aments about ½′ long during their first season, with light red-brown rather loosely imbricated scales narrowed into a long slender point, becoming when the flowers open 2′ long, with broadly obovate scales rounded and abruptly contracted at apex into a short point, ciliate on the margins, green tinged with red above the middle, light brown toward the base; pistillate aments slender, about ¼′ long, on thin hairy stems, their scales lanceolate, acute, light green, often flushed with red above the middle, hirsute at the apex, decreasing in size from the lowest. Fruit: nuts ⅓′ long, about ⅛′ wide, rather abruptly narrowed below the apex, their involucres in clusters 1½′—2′ long and ⅔′—1′ wide, on slender hairy stems about 1′ in length.

A tree, occasionally 50°—60° high, with a short trunk 2° in diameter, usually not more than 20°—30° tall, with a trunk 18′—20′ thick, long slender branches drooping at the ends and forming a round-topped or open head frequently 50° across, and slender, very tough branchlets, light green, coated with pale appressed hairs when they first appear, becoming light orange color and very lustrous by midsummer, glabrous, dark red-brown and lustrous during their first winter, and then growing gradually darker brown and losing their lustre; or covered like the petioles and peduncles with short erect glandular hairs (var. glandulosa Sarg.). Winter-buds ovoid, light chestnut-brown, slightly puberulous, ¼′ long. Bark about ¼′ thick, broken into thick narrow oblong closely appressed plate-like light brown scales slightly tinged with red on the surface. Wood strong, hard, tough, durable, light brown tinged with red or often nearly white, with thick pale sapwood of 40—50 layers of annual growth; used for fence-posts, handles of tools, mallets, and other small articles.

Distribution. Dry gravelly slopes and ridges often in the shade of oaks and other large trees; Island of Cape Breton and the shores of the Bay of Chaleur, through the valley of the St. Lawrence River, and along the northern shores of Lake Huron to western Ontario, Manitoba, Minnesota, eastern North Dakota, the foothills of the Black Hills of South Dakota, eastern, northern and northwestern Nebraska, eastern Kansas and Oklahoma, and southward to northern Florida and eastern Texas; most abundant and of its largest size in southern Arkansas and in Texas. From Quebec and Ontario to western New England, western New York, Ohio and in Central Michigan, the glandular form prevails: the two forms occur in New Jersey, Pennsylvania, Indiana, northern Illinois, southwestern Missouri, Oklahoma, and southward on the high Appalachian Mountains.

2. [Ostrya Knowltonii] Cov. Ironwood.

Leaves elliptic to obovate, acute or round at apex, gradually narrowed and often unequal at the rounded cuneate rarely cordate base, sharply serrate with small triangular callous teeth, covered with loose pale tomentum when they unfold, at maturity dark yellow-green and pilose above, pale and soft-pubescent below, 1′—2′ long, 1′—1½′ wide, with a slender yellow midrib slightly raised on the upper side, and slender primary veins connected by obscure reticulate veinlets; turning dull yellow in the autumn before falling; petioles ⅛′—¼′ long; stipules pale yellow-green, often tinged with red toward the apex, ½′ long, about ½′ wide. Flowers: staminate aments on stout stalks covered with rufous tomentum and sometimes ½′ long, rarely sessile, about ½′ long during their first season, with dark brown puberulous scales gradually contracted into a long slender subulate point, becoming when the flowers open 1′—1¼′ long, with broadly ovate concave scales abruptly narrowed into a nearly triangular point, yellow-green near the base, bright red above the middle; pistillate aments about ¼′ long, with ovate-lanceolate light yellow-green puberulous scales ciliate on the margins. Fruit: nuts ¼′ long, gradually narrowed at the apex, their involucres 1′ long, nearly glabrous at the apex, sometimes slightly stained with red toward the base, in clusters 1′—1½′ long and about ¾′ broad, on stems ½′ in length.

A tree 20°—30° high, with a trunk 12′—18′ in diameter, usually divided 1° or 2° above the ground into 3 or 4 stout upright stems 4′—5′ thick, slender pendulous often much contorted branches forming a narrow round-topped symmetrical head, and slender branchlets dark green and coated with hoary tomentum when they first appear, dark red-brown and pubescent during their first summer, becoming light cinnamon-brown, glabrous, and lustrous in the winter, and ultimately ashy gray. Winter-buds ovoid, dark brownish red, about ⅛′ long. Bark internally bright orange color, ⅛′ thick, separating into loose hanging plate-like scales light gray slightly tinged with red, and 1′—2′ long and wide. Wood light reddish brown, with thin sapwood.

Distribution. On the southern slope of the cañon of the Colorado River in Coconino County, Arizona, at altitudes of 6000°—7000° above the sea (Hance trail, seventy miles north of Flagstaff); in the cañon of Oak Creek, south of Flagstaff (P. Lowell); and on Grand River, Utah (Moab, Grant County, M. E. Jones).