ALNUS SINUATA (E. Regel).
Abzus viridis Hook. Fl. Bor. Am. 2 : 157. 1837.
Alnus viridis sinuata E. Regel in DC. Prod. i6: Part 2, 183.
1868.
Shrub 1-5 rn. high ; young bark brown and glossy with scat tered white lenticles : older bark grayish ; leaves 3-10 cm. long. oval, acute or acuminate at both ends, sinuately lobed and doubly and sharply serrate, thin, green and glabrous on both sides, very glutinous when young, in age shining ; peduncles racemiform, very warty ; staminate catkins 2 cm. long, sessile ; pistillate ones shortly ellipsoid, S—io mm. long and 6-7 mm. in diameter, on pedicels 3-15 mm. long.
It most resembles A. but is easily distinguished by the thinner, more shining leaves, which are always more or less lobed and quite without any development of pubescence. In A. 7.717d iS the veins on the lower surface are more or less ferruginously puberu lent. In the same species the pistillate catkins are generally over cm. long. A shillala has also been confounded with A. tenni folia Nutt., which, according to Sargent, is an older name for A.
incana Regel or A. lilealuz viresecils \Vats. I have not ac cess to Nuttall's Sylva and am not able to verify this point. In the plate of A. tenuifolia, in the Silva of North America, the leaves re semble more the present species than A. incana glauca, but Prof. Sargent's description and synonymy belongs evidently to the lat ter. In A. tenuifolia, z. e., A. incana glauca, the leaves have much rounder lobes and less sharp dentations, are less acuminate, thicker, and generally somewhat pubescent on the veins. The pistillate catkins are, as a rule, nearly sessile on the common peduncle.
It is fairly common in the mountain regions of Montana. (Flodman, no. 369, Spanish Basin, July 10, 1896.) In the Colum bia herbarium there are three specimens of this species, viz.: one collected by Mertens at Sitcha, one by Scouler (no. 59) from the Columbia, and one received from Hooker, but without any in dication of collector or locality. Probably it was collected by Douglas.