80 BETULACE/E. n.tida. 



2. B. glandulosa, Miclix. A low bush, 4 to 6 fuet liigli or less, tlie dark-col- 

 ored brandies usually iiioro or less resinous-glandular : leaves small (a lialf to an inch 

 long), obovato to Dblnng-obovate, nic^stly cuneate at base, rounded and crenato above, 

 on slender petioles 1 to 3 lines long, smooth and often resinous-coated : fruiting 

 aments 3 to 12 lines long; the deeply 3-lobed bracts slightly ciliate : seed orbicular- 

 winged. — Flora, ii. 180; Kegel, DC. Prodr. xvi'-'. 172; Gray, Manual, 4G0. 



Phimas County (Mrs. R. M. Austin); Oregon {Hall) ; nortliwaid to Sitka and cast tlirougli 

 British America to tlie Atlantic, in the Uoclcy Mountains, and in the colder portions of the North- 

 ern States. 



2. ALNUS, Tourii. Ai.dek. 

 Bracts of starainate aments shield-shaped and stipitate, including 5 bractlets and 

 usually 3 llowers ; perianth regular, 4-lobed. Stainejis 4, opposite the lobes, with 

 very short filaments and contiguous anther-cells. Bracts of pistillate aments lleshy 

 and imbricate, inclu<ling 4 bractlets and 2 flowers, cuneate and slightly 4-lobed, in 

 fruit persistent and woody, thickened and truncate above, at length divergent. 

 Nuilets compressed, mostly wingless or nearly so. — Shrubs or small trees, in moist 

 places, with smooth bark, the llowers preceding or appearing with the leaves ; 

 aments terminating leafless branchlets or peduncles, the staminatc long and droop- 

 ing, the pistillate ovoid or oblong, erect. 



A genus of about 15 species, half of them Amorican. The tinilier is almost imperisliaLle in 

 water, the wood is vahiaMe in cabinet work, tlie bark is useil for tanning and dyeing, and 

 the charcoal is usually employed in the manufacture! of gunjiowder. The (^difornian sjiecies 

 belong to section Gijiunufhijrsus, Spach, tlie llowers preceding the leaves, and the racemed aments 

 formed the previous yeai-. 



« Fruit sin'roinidcd hij a narrow sowctrluit mciiiI>ranous toiuf/. 



1. A. rubra, l>ongard. Jiranches rather stout, dark brown dotted with white: 

 leaves thick, rusty-})ubescent beneath, glabrate above, ovate to elliptic, 2 to G 

 (sometimes 8) inches long, acute, rounded or more or less cuneate at base, coarsely 

 and rather obtusely toothed, the teeth crenate and margin narrowly revolute : fruit- 

 ing aments roundish ovate to oblong, a half inch or sometimes an inch long, the 

 bracts much thickened above: nutlets 1] lines long, nearly orbicular or obovate. 

 — Veg. Sitch. 1G2; Kegel, DC. Prodr. xvil 18G. A. Orer/ana, Kutt. Sylva, i. 28, 

 t. 9. A. incana, var. rubra, Kegel, Monogr. 99, t. 17, Jig. 3, 4. 



From Sitka to San Francisco; fie(iuent on the Oakland Hills. Described by Nuttall as be- 

 coming 30 or 40 feet high, and Dolander speaks of it as a large tree. 



•^ * Fruit more or less acutdij maryincd, not 2v!nr/ed. 



2. A. rhombifolia, Tsutt. Branches more slender, dark brown, scarcely dotted : 

 leaves slightly pubescent beneaUi, sinoothish above, ovate (or obovate) to ovate- 

 oblong, 2 or 3 inches long, rounded at the summit or acute, cuneate at base, irregu- 

 larly glandular-denticulate : fruiting aments oblong, 6 to 8 lines long, the bracts 

 rather thin above : nutlets a line long, very broailly obovate, with a thickened 

 margin. — Sylva, i. 33. A. glntinosn, var. serriilata, Kegel, Monogr. lOG, in part. 

 A. serruhdn, var. riKjom, Kegel, DC. Prodr. xvi'^, 188, in i)art. 



From Oregon (Ihtll) to Southern California; at San Felipe {I'uhncr), known as "White 

 Alder." "The common Calilornia alder, 20 to 30 feet liigli and 2 or 3 leel in diameter," ac- 

 cording to Bolnndcr ; 30 to iJO feet high, Pcckkam. Bark light ash-gray. 



3. A. oblongifolia, Torrey. Branches light brown, sparingly dotted : leaves 

 thick, slightly pubescent or glabrous beneath, smooth above, oblong-lanceolate, 2 to 

 6 inches long, acute or acuminate, cuneate at base, serrate, the teeth with scattered 

 glandular denticulations : staminate aments stout, 2 to 4 inches long : fruiting 



