ALNUS INCANA (Linnæus) Muenchhausen. Speckled Alder. (× 1/2.)
Distribution.—Newfoundland to the Saskatchewan, south to New York, northeastern Ohio, northern Indiana and Nebraska. In Indiana it is confined to the northern tier of counties. I have specimens from Elkhart, Lagrange, Lake and Porter Counties. It was reported from Carroll County by Thompson, but in the absence of a verifying specimen I am inclined to think this citation should be referred to Alnus rugosa. This species grows in low ground on the borders of streams, borders of swamps and in almost extinct sloughs near Lake Michigan. It is also found along Pigeon River in the eastern part of Lagrange County. In the vicinity of Mineral Springs in Porter County it is locally a common shrub or tree. It has the habit of stooling out, and commonly the several specimens will be deflected from a vertical from 20-45 degrees. The largest specimens are from 1-1.4 dm. in diameter and about 10 m. high.
Remarks.—This species could be used to good advantage in ornamental planting in low ground. It grows rapidly, is easily transplanted and its foliage is dense and attractive.
2. Alnus rugòsa (Du Roi) Sprengel. Smooth Alder. [Plate 37.] Shrubs with fluted or angled trunks, resembling Carpinus; bark thin, smooth or nearly so, reddish-brown, weathering gray; twigs hairy at first, becoming gray or reddish-brown by the end of the season and more or less glabrous and covered with small dark specks; leaves obovate, barely acute or rounded at apex, wedge-shape at base, average blades 6-10 cm. long, hairy on both surfaces while young, becoming smooth or nearly so above, remaining more or less hairy beneath, especially on the veins, under surface of leaves sufficiently glutinous to adhere to paper if pressure be applied, margins set with short callous teeth, about .5-1 mm. long; fertile catkins cone-shape, 10-20 mm. long and about 7 mm. in diameter, borne at the ends of branches in clusters of 2-5.
Distribution.—Maine to Minnesota, south to Florida and Texas. In Indiana it is quite local. It has been reported in many of the counties of northern Indiana north of the Wabash River. It has been found in several of the southern counties and as far north as Salt Creek in Monroe County. No reports for the central part of the State. It is absent also in all of the eastern counties of the State, and the western part of Ohio. It is found growing in clumps in wet woods, swamps, cold bogs and along streams. It is usually a tall slender shrub; however, a specimen has been seen that measured 7 cm. in diameter and 5 m. in height.
Remarks.—Of no value except for ornamental planting in wet ground.