90 



Hovey Lake in Posey County it reaches its greatest size, where trees 

 up to 8 dm. in diameter and 30 m. high are to be found. In the "flats" 

 in certain parts of Jackson and Scott Counties it becomes a common 

 tree, associated with pin oak and sweet gum. 



Remarks. This is the most abundant birch of Indiana. In fact all 

 other species are too rare to be of economic importance. The fact that 

 other species of birch are so rare in Indiana, is the reason that this 

 species is simply called "Birch." Outside of Indiana it is known as red 

 birch and river birch. The principal use of this wood in this State is 

 for heading. 



All of the birches, especially the horticultural forms, are used more 

 or less for ornamental planting. They are beautiful trees but are 

 short lived. 



4. ALNUS. THE ALDERS. 



Trees or shrubs; bark astringent; staminate and pistillate catkins 

 begin to develop early in summer and flower the following year early in 

 the spring before the leaves appear; bracts of the fertile catkins thick 

 and woody, obdeltoid with 3-rounded lobes at the apex; nuts obovate, 

 reddish-brown. 



Leaves sharply double-serrate, the ends of the primary veins 



forming the apex of the larger teeth, glaucous beneath; 



nuts with a narrow thick margin 1 A. incana. 



Leaves single -serrate, pale beneath; nuts without margins. . . 2 A. rugosa. 



1. Alnus incana (Linnaeus) Muenchhausen. SPECKLED ALDER. 

 Plate 36. Shrubs or small trees; bark generally smooth and a red- 

 dish-brown with a tinge of gray, with grayish dots, hence its name; 

 twigs hairy at first, becoming smooth by the end of the season and a 

 golden or reddish-brown with many fine dark specks; leaves broadly- 

 oval, acute or short-pointed at apex, usually broadly rounded at the 

 base, average blades 6.5-11 cm. long, glaucous beneath, hairy on 

 both sides on unfolding, at maturity becoming glabrous above or 

 with a few hairs on the veins, beneath remaining more or less hairy 

 until late in autumn when usually only the veins are hairy; pistillate 

 catkins resembling small cones, 1-1.5 cm. long and usually 7- 12 mm. wide, 

 near the ends of the branches, usually in clusters of 2-7. 



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 speci- 

 men I am inclined to think this citation should be referred to Alnus 



