150 American Midland Naturalist Monograph No. 7 



1. Leaves with 4-7 veins on each side of midrib; small tree; nat. from 

 Eur. in a few places in Cook, Du Page, Piatt, and Will counties. 

 Black Alder. [A. vulgaris Hill] A. glutinosa (L.) Gaertn. 



3. Corylus L. — Hazel 

 C. americana Walt. Thickets and borders of woods throughout 111. 

 Mar.-Apr. 



4. Carpinus L. — Blue Beech 



C. caroliniana Walt. Muscle Tree. Woods, common. Apr. -May. 



5. Ostrya Scop. — Ironwood. Hop-hornbeam 

 O. virginiana (Mill.) K.Koch. Woods, common. Apr.-May. 



67. Juglandaceae Lindl. — Walnut Family 



1. Pith of twigs lamellate or chambered; staminate catkins sessile or nearly so; 

 leaflets conduplicate in vernation; nut enclosed in an indehiscent husk 

 1. Juglans 



1. Pith solid; staminate catkins slender, long-peduncled; leaflets involute in 

 vernation; husk of nut splitting into 4 halves 2. Carya 



1. Juglans L. — Walnut 



1. Fruit subglobose, obtuse, papillose, not viscid; leaf-scars without a 

 tuft of hairs on upper margin; bark dark brown, the ridges 

 rough; stamens 20-30; nut corrugated, 4-loculed at base; woods, 

 common. May. Black W^alnut /. nigra L. 



1. Fruit ellipsoid, pointed, viscid; leaf-scars with a pubescent fringe 

 along the upper margin; bark gray, the ridges smooth; stamens 

 8-12; nut 4-ribbed, deeply sculptured, 2-loculed at the base; 

 woods, rare. May. Butternut /. cinerea L. 



2. Carya Nutt. — Hickory 

 {Hicoria Raf. ) 



1. Leaflets 9-17 (usually 13), lanceolate, acuminate, the lateral ones 

 somewhat falcate ; bud-scales 4 or 6, valvate. 

 2. Rachis and lower surface of leaflets pubescent; staminate catkins 

 fascicled; nut smooth, ellipsoid; seed edible, not bitter; river- 

 bottom woods, common; extending northward to Jo Daviess, 

 Peoria, Woodford, Fayette, and Lawrence counties. Apr.- 

 May. Pecan. [C. pecan (Marsh.) Engler & Graebn.] 



C. illinoensis (Wang.) K.Koch 



2. Leaves glabrous or nearly so; catkins in threes on a common 

 peduncle; nut sharply angled; seed very bitter; bark of old 

 trunks exfoliating in long strips; river-bottoms, rare, s. 111.; 

 known from Alexander, Gallatin, Massac, Pulaski, and Union 



counties. Mar.-Apr. Water Hickory. Bitter Pecan 



C. aquatica (Michx.f.) Nutt. 



1. Leaflets 5-9 (rarely 11). 



