CXXVI. MYRlCACEiE. 499 



Slirub '2 — 31' hij?h, mountains, N. Y. and Pcnn. Pursk. " In several low places 

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

 (fide Vuckcrman.) A very obscure species, unless it be the lollowing. 



7. B. GLANDULOSA. Michx. Glandular Dwarf Birch. 



Low ; broficht's f^landular-punclate, glabrous ; Irs. obovatc, entire at base, 

 obtusely serrate, glabrous; fertile anictits oblonj^ ; scales half3-elel't, lobes ovate- 

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

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

 States ! N. to Hudson's Bay. Height 2 — 41". Leaves about 9" by C or 7", very 

 regularly toothed. — If this shrub be distinct from the preceding, it may be known 

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

 variable leaves. 



8. B. LiTTELLiANA. Tuclvcrman. 



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

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

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

 — 4 times larger than those of B. nana. 



9. B. NANA. Tiny Birch. 



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

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

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

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

 few and straggling, the leaves ^ — §' 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 cuneato, 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 ; rcms hirsute, 

 their axils naked ; stip. oblong-lanceolate; fertile amentsoval. — 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. Willd and l5^ 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 \ — ^' 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. Ait.) 



Lvs. oval, acute, obtusi.sh at base, doubly 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., Tuckervian, 

 Green Mts., RMins, Can., Michaux. An elegant shrub, 3 — 4f high. Leaves 

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

 wise softly pubescent and sprinkled with resinous particles. Apr, 



Order CXXVI. MYRICACEJE.— Galeworts. 



Shrubs or »7)}a/l trees, aromatic^overed with resinous glands or dots. Irs. alternate, simple. 



Fis. monorious or dia-cious. amentaceous, each axiliarj' to a bract. 



Steri/e.—Sta. 2—6. Anth. 2— 4-celled, opening longitudinally. 



Fertile.— Ova. l-celled, l-oviiled, surrounded by several hypogj nous scales. 



