alnus BETULACEiE 615 



MYR1CA 



feet high and 1-4 feet in diameter, with dark brown bark blotched with 

 white: leaves oval to elliptic, thickish, dark green above, pale or whitish 

 beneath with prominent rusty-pubescent veins, coarsely serrate and finely 

 serrulate, 2-8 inches long, acute or shortly acuminate, rounded or narrowed 

 below to petioles 6-18 lines long : staminate aments reddish, 2-6 inches 

 long; the pistillate ovoid to oblong, 6-12 lines long, the bracts much thick- 

 ened above: nutlets more than a line long, nearly orbicular or oblong, 

 surrounded by a narrow somewhat membranous wing. Common in moist 

 places, California to Alaska. 



A. rhombifolia Nutt. Sylva, i, 33. A tree 30-50 feet high, with white 

 bark which becomes broken rectangular flakes: leaves rhombic-ovate to 

 elliptic or obovate, mostly cuneate at base and obtuse at the apex, 2-3 

 inches long, irregularly glandular-dentate: fruiting aments oblong, 6-8 lines 

 long, the bracts rather thin above: nutlets a line long, very broadly obovate 

 with a thickened margin. Eastern Washington to California. 



A. tenuifolia Nutt. A. incana var. virescens Watson. A shrub 4-20 

 feet high with brown bark : leaves more or less broadly ovate, 2-3 inches 

 long, acute, rounded or slightly cordate at base, acutely doubly toothed, 

 light green and glabrous on both sides, or sparingly pubescent : staminate 

 aments rather slender, 1-2 inches long: fruiting aments ovate-oblong, 4-6 

 lines long: nutlets roundedobovate, slightly margined, 1% lines long. In 

 wet places in the mountains, Alaska to California and the Rocky Mts. 



A, serrulata Willd Sp. PI. iv, 336. A. rugosa K. Koch. A shrub 

 5-10 feet high, or sometimes a small tree 40 feet high, with smooth bark, 

 the young shoots sometimes pubescent : leaves green both sides obovate or 

 oval, mostly obtuse or rounded at the apex, narrowed or rounded at base 

 sharply and minutely serrulate when mature, glabrous above, usually 

 pubescent on the veins beneath, 3-5 inches long, on petioles 4-12 lines long : 

 aments appearing from naked buds much before the leaves, the staminate 

 2-4 inches long, the pistillate ovoid 5-9 lines long when mature :nutlets 

 ovate, narrowly coriaceous-margined. In wet soil. Idaho to the Eastern 

 States. 



A, sinuata Rydb. A small tree or shrub 9-15 feet high, erect or as- 

 cending: bark rather dark except on old stems: leaves ovate, acuminate, 

 obtuse or cuneate at base, bright green, doubly dentate, glabrous above, 

 nearly ao beneath, thin, very gummy when young, 2-4 inches long, on 

 slender petioles 5-12 lines long : fruiting aments 7-9 lines long, on slender 

 longer peduncles. Eastern Washington. 



Order XCI MYRICACE^E Dumort. Anal. Fam, 95. 



Shrubs or trees with alternate simple leaves and small dioecious 

 or monoecious flowers in bracted aments without calyx or corolla. 

 Flowers solitary in the axils of the bracts : staminate with 2-15 

 stamens inserted on the receptacle: filaments short distinct or 

 somewhat united: anthers ovate, 2-celled, the cells longitudinally- 

 dehiscent: pistillate with a solitary 1-celled ovary subtended by 

 2-8 bractlets: ovules solitary, orthotropous : style very short: 

 stigmas 2, linear. Fruit a small drupe or nut, often waxy. Seed 

 erect, orthotropous, with thin testa and no albumen. 



1 MYRICA L. Sp. 1024. 



Shrubs or small trees with alternate mostly resinous-dotted 

 leaves and small flowers in bracted aments. Staminate aments 

 oblong or narrowly cylindric expanding before or with the leaves. 



