FERNALD, — ALNUS. 27 
de Cuyamecalco, alt. 2155 m., Apr. 24, 1895 (L. C. Smith, no. 495). 
Said to be a large tree. 
* * Mature strobiles less than 2 cm. long (exceptional plants of A. oblong ign 
and A. glabrata may be looked for here). 
+ Mature leaves ferrugineous-velutinous beneath. 
A. ferruginea, HBK. Branches brown, the younger parts more 
or less pubescent: buds very pubescent: leaves ovate, acuminate at tip, 
rounded or narrowed at base, coarsely and doubly serrate, 0.5 to 1.5 
dm. long, 3.5 to 8 cm. broad, dull green and minutely pilose above ; 
petiole thickish, 1 to 2 cm. long: peduncles villous or glabrate, the 
staminate aments becoming 1.5 dm. long: the dark brown short-oblong 
strobiles subsessile or short-stalked, in maturity 1.5 to 1.9 cm. long, about 
1 cm. thick: nutlets cuneate-obovate, 3 mm. long, 2 mm. wide, with nar- 
- rower coriaceous wings. —HBK. 1. ec. 21. A. acuminata, § ferru- 
ginea, Regel, 1. c. 184; Hemsl. 1. e. 165. — Described from Colombia. 
Extending into Central America and Southern Mexico. Cntapas 
( Ghiesbreght, no. 160): GuatemaLa, Coban, Alta Verapaz, alt. 1488 m., 
Feb. 1886 (#1. von Tuerckheim in Exsice. J. D. Smith, no. 351). 
++ Mature leaves merely pilose on the nerves beneath. 
A. jorullensis, HBK. Branches reddish brown, smooth, the 
younger parts puberulent or glabrate: buds pruinose: leaves oblong or 
oblong-obovate, thick, mostly 7 to 13 em. long, 2.5 to 5.5 cm. wide, 
rounded or acute at tip, subcuneate or rounded at the subentire base, 
crenate-serrate toward the tip, glaucous and sublucid above, brownish 
beneath and closely pruinose with glandular or waxy atoms, the prom- 
inent nerves more or less pilose; petioles thickish, 3 to 10 mm. long, 
pubescent or glabrate: peduncles thick, pruinose or glabrate ; staminate 
aments 8 or 4, becoming 6 cm. long; the reddish-brown strobiles 3 or 4, 
sessile or subsessile, oblong-ovoid, 1 to 1.8 em. long, barely 1 cm. thick: 
nutlets cuneate-obovate to suborbicular, 2.6 mm. long, 2 to 2.5 mm. 
broad, with narrow membranaceous wings. — HBK. 1. c. 20; Regel, 
].c.; Hemsl. 1. ¢. 166, in part. 4. acuminata, Sargent, 1. ¢. in part, not 
HBK. Sierra Madre of Central and West-Central Mexico. Described 
from Volean de Jorullo, Michoacan. Micnoacan, mountains near 
Patzeuaro, Dec. 21, 1891 (C. G. Pringle, no. 5057); Sierra Madre, 
without locality (Seemann): Mexico, foothill of Mt. Ixtaccihautl, Jan. 
5, 1899 (C. C. Deam, no. 130). 
Var. exigua, n. var. Leaves short-oblong, 2 to 4 em. long, 1 to 
