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 .Ja(dvson and Scott Counties it becomes a common 

 tree, associated witli pin oak and sweet gum. 



Remarks. — This is the most abundant liircli of Indiana,. In fact all 

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

 other species of birch ai'c so rare in Indiana, is the reason that this 

 species is sim])ly called "Birch." (Xitside of Indiana it is known as red 

 liirch and river l)irch. The principal use of this wood in this State is 

 for heading. 



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

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

 shoi't lived. 



4. ALNUS. TuE Alders. 



Trees or shrubs; bark astringent; staminate and jiistillale catkins 

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

 the spring before the leaves appear; l)racts of the fertile catkins thick 

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

 reddish-brown. 



Leaves sharply (loiible-sei-ratc, the (ind.s of the j)riinar.\' veins 



forming the apex of the hirger teetli, tjlaucous bciioalli; 



nuts\Aith a narroAV tliick margin 1 A. inf-ana. 



Leaves sin^li'-scrrati-', pidr liencath; nuts \vith<jut margins. . . 2 A. ruffosa. 



1. Alnus incaua (Linnteus) Muen(;hhausen. Speckled Alder. 

 Plate 3G. Shrtd)S or small trees; bark generallj^ smooth and a red- 

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

 twigs haii'y at first, becoming smooth by the; end of the season and a 

 golden or reddish-brown with many fin(^ dark specks; leaves broadly- 

 oval, acute or short-pointed at apex, usvuT,lly broadly I'ounded at the 

 base, average Ijlades (i.5-11 cm. long, glaucous beneath, hairy on 

 l)oth sides on unfolding, at maturity becoming glabrous above or 

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

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

 catkins resembling small cones, 1-1 .5 cm. long and usually7-12mm. wide, 

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



Distribution. — Newfoundland to the Saskatchewan, south to New 

 Yoik, noitheastern (Jliio, northei'u Indiana and Nebraska. In Indiana 

 it is confined to the noi-fhein 1 iei' of counties. I liave specimens from 

 Elkhart, Lagiange, Lake and Poi'ter Counties. It was ]-(>]50i-ted from 

 Carroll County by lliompson, Ijut in the al)sence of a verifying speci- 

 men I am inclined to think this citation should bi; referred to Alnus 



