FERNALD. — ALNUS. 25 



* Mature strobiles 2 cm. or more long (rarely shorter in A. ohlongifolia and A. 



glabrala). 



■*- Petioles pubescent. 



■I-*- Leaves ovate to obovate, rounded at base. 



A. acuminata, II BK. Bark of branches asliy brown, smooth : buds 

 pubescent : leaves short-acuminate, finely and doubly serrate-dentate, 

 0.5 to 1.5 dm. long, 0.4 to 1 dm. broad, subcoriaceous, sparingly pilose 

 on the midrib above, more abundantly so on the midrib and nerves 

 beneath; petiole about 1 to 1.5 cm. long: peduncles stout, glabrous or 

 minutely puberulent : staminate aments becoming 1 dm. or more long ; the 

 ashy-brown strobiles 3 or 4, sessile or short-pedicelled, ovoid-oblong, 2.2 to 

 2.6 cm. long, about 1.5 cm. thick : nutlet lanceolate, 4 mm. long, 1.75 

 mm. broad, bordered by an equally broad coriaceous wing. — Nov. 

 Gen. & Sp. ii. 20; Kegel in DC. Prodr. xvi, pt. 2, 183. Described 

 from the Andes of Peru, this species has been made to include practically 

 all the forms of South America, Mexico, California and New Mexico. 

 From the original description, however, the species appears to be a well 

 marked plant represented in the Gray Herbarium from Guatemala and 

 Bolivia. Guatemala, San Lucas, Dept. Zacatepequez, alt. 1700 m., 

 April, 1890 (/. B. Smith, no. 2188): Bolivia {Bang, m. 1893). 



++ -w- Leaves oblong-lanceolate or elliptic, subcuneate at base. 



A. oblongifolia, Torr. Bark of branches reddish brown, smooth ; 

 of the branchlets puberulous or glabrate : buds glabrous : leaves acute, 

 sharply double-serrate, 0.5 to 1.5 cm. long, 3 to 6.5 cm. broad, more or 

 less glandular-dotted, coriaceous, pilose or glabrate above, paler and 

 more or less pilose on the prominent veins beneath ; petioles slender, 

 1 to 2.0 cm. long: peduncles puberulent or glabrate: staminate aments 

 becoming 1 dm. long ; the brown or slightly ferrugineous strobiles 3 to 5, 

 pedicelled, sub-cylindric, when mature about 2 cm. long, 1 cm. thick : 

 nutlet obovate, 3 ram. long, 2 mm. broad, with a narrow submembra- 

 naceous wing. — Bot. Mex. Bound. 204. A. serrulata, y ohlongifolia, 

 Kegel, 1. c. 188. A. acuminata^ Sargent, Silva, ix. 79, t. 457, iu part, 

 not HBK. — Nkw IMexico, banks of the Mimbres and near Santa Bar- 

 bara, tree 9.23 m. high (Charles Wright, no. 1864): California, San 

 Bernardino, "tree 80 feet high, 2-3 feet in diameter," 1876 (C. C. 

 Parry ^ J. G. Lemmon). Sonora, Huchuerachi, alt. 1230 m., Dec, 

 1890 (C. V. Hartman, no. 322, F. E. Lloyd, no. 464). 



