206 CORYLACEAE 



branched at the tips; anther-sacs separate, pilose above. PistiUate aments 

 terminal sohtary; bracts subtending two flowers, developing into bladdery 

 sacks. Calyx denticulate. Nut ovoid, flattened, obscurely ribbed. 



1. O. virginiana (Mill.) K. Koch. A tree fr-18 m. high; twigs light green and 

 pubescent at farst; leaf-blades ovate or oblong-lanceolate, acuminate at the apex, 

 sharply serrate, 7-15 cm. long; staminate aments 3-7 cm. long; bractlcts tri- 



aneular-OVate. aciiminn+p- niafilloto omonfc, cK.^,,+ o ™™ .• e^..?L A r, 1 "^ 



nut ^8 mm long, shining. Dry woods: N.S.—Fla.— Tex.— (Black Hills) S.D.' 

 oubmont. Ap-My. ' 



2. CORYLUS (Tourn.) L. Hazelnut. 



Shrubs or trees, with branched stem and smooth bark. Staminate aments 

 pendulous, very long, solitary or in clusters; bracts enclosing 4-8 stamens; fila- 

 ments short, forked at the apex; anther-sacs separate, pilose at the apex. Pis- 

 tiUate aments inconspicuous, clustered at the tips of the branches; each bract 

 enclosmg 2 bractlcts and an incompletely 2-celled ovary. Nut large, enclosed 

 m a leafy involucre formed by the more or less united bracts. 



'^'^ ribbed*"""''^ °'" °^'"**' ^°'' ^^^^ °'" **"' involucre fully twice as long as the nut, strongly 



'^'''ih\nS^fnL?^h^n^f!''^''*i™^^'^.'"^^^^ l^eak of iavolucre''*'not more 



tnan Half longer than the nut, not strongly ribbed. 2. O. califurnica. 



1. C. ro3trata Ait. A shrub 1-2 m. high, with brown branches; leaf-blades 

 ovate or oval, sharply serrate, glabrous or with scattered hairs above, sparingly 

 pubescent especially on the veins beneath, 5-12 cm. long; involucral bracts 

 bristly hau-y, united and prolonged into a tubular beak, laciniate at the summit; 



nut ovoid, scarcely compressed, striate. Beaked Hazlenut. Thickets: N.S. 

 — Ga.— Colo.— N.D. Suhmout. Ap-My. 



2. C. californica (A DC.) Rose. A shrub, or smaU tree, up to 12 m. high, 

 with brown pubescent branches; leaf-blades broadly ovate to suborbicular, 

 Z.b-7 cm. long, cordate or rounded at the base, double-toothed, rough and 

 pubescent above, soft-pubescent and paler beneath; involucral bracts bristly 

 hauy, united into a tube, cleft at the apex; nut rounded-ovoid, 1.5 cm. in di- 

 ameter. Woods: Calif.— B.C. Son.—Submont. 



Family 34. ULMACEAE. Elm Family. 



Monoecious, polygamous, or hermaphrodite trees or shrubs, with simple 

 leaves, often 2-ranked and oblique at the base. Flowers in cymes or racemes. 

 Caly:t ot 6-8 sepals, more or less united at the base, imbricate. Stamens of 

 the same number, opposite the sepals. Pistil of 2 united carpels; ovary 

 ^-ceiled, fruit a samara, drupe, or nut. Endosperm scant or wanting. 



Fruit a samara; embryo straight. i TTiMiTa 



Fruit a drupe ; embryo with condupUcate cotyledons. 2." Cel^'is; 



1. tJLMUS (Tourn.) L. Elm. 



Trees or shrubs, with furrowed, often corky bark. Leaves 2-ranked, oblique, 

 straight-veined, serrate, deciduous. Flowers perfect, in axillarv clusters. Calyx 

 membranous, 4-9-lobed usually 5-lobed, campanulate. Stam'ens exserted; fila- 

 ments hhform or shghtly flattened; anthers extrorse, emarginate at both ends. 

 Uyary sessile or short-stalked, 1-celled or rarely 2-ceUed; stigmas often incurved, 

 mtrorse. Samaras orbicXilar or oblong, winged all around. Seeds flattened. 



1. U. americana L. A large tree, sometimes 35 m. high, with glabrous or 

 sparmgly pubescent twigs; leaves oval or obovate, abruptly acuminate at the 

 ^Pe^; obtuse or acutish at the obUque base, sharply, usually doubly serrate, 

 slightly rough above, pubescent or glabrate beneath, 5-12 cm. long; samara 

 oyate-oyal, reticulate-veined, 10-12 mm. long, glabrous except the ciliate mar- 

 gins. American or White Elm. Moist soil: Newf.— Fla.— Tex — se Mont — 

 Sask, Plain — Submont. Mr-Ap. 



