CXXVI. MYRICACE.E. 499 



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

 towards the hills " Penn. Bartram. Cedar swamps, Columbus, Ohio, Sullivant 

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



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



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

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

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

 beautiful 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 distinct from the preceding, it maybe known 

 6y its gfandular-dotted branches and its want of pubescence scarcely by its 

 variable leaves. 



8. B. LITTELLIANA. Tuckerman. 



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

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

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

 4 times larger than those of B. nana. 



9. B. NANA. Tiny Birch. 



Low, smooth ; Ivs. orbicular, crenate, 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 White 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. 



<? 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, acutfsh, obtuse at base or cordate, mar- 

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

 their axils naked ; slip, oblong-lanceolate ; fertile aments oval. 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. RTJBRA. Marsh. (A serrulata. Willd and 1st edit.} Common Alder. 

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



beneath ; stip. 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 J as wide, 

 strongly veined ; petioles j J' long. Aments 2 3' long, slender, pendulous, 

 fascicled 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, obtusis^ at base, doubly serrate, clothed with a soft vis- 

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

 broadly ovate ; fertile aments on long peduncles, oval. White Mts., Tuckcrman, 

 Green Mts., Bobbins, 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. MYBICACEJS. GALEWORTS. 



Shrubs or small trees, aromatic, covered with resinous glands or dots. Lvs. alternate, simple. 



Fit. monoecious or dioecious, amentaceous, each axillary to a bract. 



Sterile. Sta. 26. Anth. 2* t-celled, opening longitudinally. 



Fertile. Ova. l-celled, 1-ovuled, surrounded by several hypogynous acales. 



