CXXVI. MYRICACEiE. 499 



Shrub 2— 3f high, mountains, N. Y. and Penn. Pursh. " In several low places 

 towards the hills " Penn. ISartram. Cedar swamps, Columbus, Ohio, SuUivant 

 (fide TiLckerman.) A very obscure species, unless it be the following. 



7. B. GLANDCLOSA. Michx. Glandular Dwarf Birch. 



Low ; branches glandular-punctate, glabrous ; Ivs. obovate, entire at base, 

 obtusely serrate, glabrous ; fertile avients oblong ; scales half 3-cleft, lobes ovate- 

 oblong, middle one rather longest ; nut orbicular, with a narrow margin. — A 

 beauiiful shrub, inhabiting the mountainous districts of the N, and N. W. 

 States ! N. to Hudson's Bay. Height 2— 4f Leaves about 9" by 6 or 7", very 

 regularly toothed. — If this shrub be distinctfrom the preceding, it maybe known 

 by its glandular-dotted branches and its want of pubescence — scarcely by its 

 variable leaves. 



8. B. LiTTELLiANA. Tuckcrmau. 



Low, glabrous ; branches resinous-punctate ; Ivs. suborbicular, coarsely 

 serrate ; fertile aments oblong-cylindric, scales trifid, lobes oblong-obovate, mid- 

 dle one longest. — White Mts., Tucker man. Shrub somewhat erect. Leaves 2 

 — 4 times larger than those of B. nana. 



9. B. NANA. Tiny Birch. 



Low, smooth ; Ivs. orbicular, crenale, reticulated beneath ; scales of the 

 avient deeply 3-parted ; seeds orbicular, nearly wingless. — This miniature tree 

 is found on the summits of Mt. Clinton, Mt. Franklin, &c., of the White Mts. ! 

 It is scarcely more than a foot in height, often but a few inches, the branches 

 few and straggling, the leaves \ — i' in diameter, smooth both sides, pale and 

 distinctly reticulate beneath, and on petioles 1 — 2" long. 



2. ALNUS. Tourn. 

 c? Ament long, cylindric, composed of cuneate, truncate, 3-lobed, 

 3-flowered bracts ; cal. 4-parted ; sta. 4. 9 Ament ovoid ; bracts 2- 

 flowered ; 3-fid ; cal. ; nut wingless, compressed. — Shrubs, arising 

 from large and strong roots. Buds pedunculate. Lvs. plicate in ver- 

 nation., alternate.) simple., deciduous. 



1. A. iNCANA. Willd. (A. glauca. Michx. Betula incana. Linn.) 



Lvs. submembranaceous, oblong, acuLish, obtuse at base or cordate, mar- 

 gin somewhat lobed, sharply serrate, glaucous-pubescent beneath; rems hirsute, 

 their axils naked; slip, oblong-lanceolate; fertile aments ovaX. — Not uncommon 

 in N. Eng. and Mid. States. A tall shrub or small tree, readily distinguishable 

 by the form and pubescence of the leaves. 



2. A. RUBRA. Marsh. (A serrulata. WUld and \st edit.) Cammon Alder. 

 Lvs. obovate, acuminate, doubly serrulate, the veins and their axils hairy 



beneath; slip, elliptical, obtuse. — A well known shrub growing in clumps, and 

 forming thickets on the borders of ponds and rivers, and in swamps. Stems 

 numerous, rather straight, 10 — 15f in height. Leaves 2 — 4' long and § as wide, 

 strongly veined; petioles i — i' long. Aments 2 — 3' long, slender, pendulous, 

 lascicled at the ends of the branches; fertile ones short, thick, dark brown, per- 

 sistent, several together a little below the sterile ones. March, April. 



3. A. CRispA. Michx. (Betula crispa. Ail.) 



Lvs. oval, acute, obtusish at base, aoubly serrate, clothed with a soft vis- 

 cid pubescence, or subglabrous, villous on the veins and axils beneath ; slip. 

 broadly ovate ; fertile aments on long peduncles, oval. — White Mts., T^ickerman, 

 Green Mts., R'blnns, Can., Michaux. An elegant shrub, 3 — 4f high. Leaves 

 varying to broad-ovate, rarely rordate, nearly smooth in the alpine state, other- 

 wise softly pubescent and .sprinkled with resinous particles. Apr. 



Order CXXVI. MYIlICACEiE.— Galeworts. 



Shrubs or small trees, aromatic, covered with resinous glands or doU. Lva. alternate, umpls. 

 F!s. mona-ciou.H or dia-cious, umentiireous, each uxiilary to a bract. 

 Sterile.— Fita. 2—6. Anth. 2— J-ceilcd, opening longitudinally. 

 Ftrtile.—Ova. 1 colleil, lovul«d,giirroundod l>y ncvornl hypogynons icaloi. 



