374 



Betulaceae 



Corylus 



Map 771 

 Betula lutea var. macrolepis Fern. 



50 



Map 772 



Betula populifolia Marsh. 



D~ ~ 13 

 Map 773 



Betula papyrifera Marsh. 



rare in the Lower Wabash Valley. It prefers a dry soil, is of slow growth, 

 and since it has no commercial value in Indiana, it is regarded by foresters 

 as a weed tree. 



N. S. to Man., southw. to Va., Ga., Tenn., Mo., and Okla. 



la. Ostrya virginiana f. glandulosa (Spach) Macbr. (Field Mus. Nat. 

 Hist. Publ. Bot. Ser. 4: 192. 1929.) Map 769. This form has the branch- 

 lets, petioles, peduncles, and often the midrib and veins of the lower sur- 

 face of the leaves covered more or less with short, erect, reddish, glandular 

 hairs. The form is found with the species but is not as frequent and is 

 more northern in its distribution. 



1886. CORYLUS [Town.] L. 



1. Corylus americana Walt. American Hazelnut. Map 770. Infre- 

 quent to frequent throughout the state. It adapts itself to both moist and 

 dry soils but reaches its greatest size in the moist, black loam soils of the 

 northern part of the state. 



Maine to Sask., southw. to Fla. and Okla. 



1887. BETULA [Tourn.] L. Birch 



Bark of small branches usually with some wintergreen flavor; leaves with 7-15, 

 usually Il-ll pairs of prominent veins, rounded, subcordate or narrowed at the 

 base; mature fertile catkins generally more than 10 mm in diameter, sessile. 

 Outer side of scales of fruiting catkins more or less pubescent. 



Scales of fruiting catkins 5-8 mm long, basal part 1-2.5 mm long 1. B. lutea. 



Scales of fruiting catkins 8-13 mm long, basal part 2.5-6 mm long 



la. B. lutea var. macrolepis. 



Outer side of scales of fruiting catkins glabrous. (See excluded species no. 173, 



p. 1039.) B. lenta. 



Bark of small branches usually bitter, without wintergreen flavor; leaves with 4-11, 

 usually 4-9, pairs of prominent veins, narrowed or truncate at the base; mature 

 fertile catkins less than 10 mm in diameter (sometimes more than 10 mm in 

 B. nigra), pedunculate. 



