152 American Midland Naturalist Monograph No. 7 



to Adams, Mason, Champaia;!!, and Vermilion coun- 

 ties. Apr.-Jime. Small-fruited Hickoiy. False Shag- 

 bark. [C. rnicrocarpa Nutt.] C. ovalis (Wang.) Sarg. 



7. Leaflets usually 5, rarely 7 or 3, glabrous; outer bud-scales, 

 rachises, and twigs glabrous; fruits obovoid to subglobose, 

 2-4 cm long, the husk tardily splitting to near the mid- 

 dle; woods throughout 111., not infrequent. Pignut 

 Hickory. [C megacarpa Sarg.] C. glabra (Mill.) Sweet 



68. Myricaceae Horan. — Bayberry Family 



1. Comptonia LHer. — Sweetfern 



C. peregrina (L.) Coult. Open woods in Cook, Kankakee, Will, 

 and Winnebago counties. Apr.-May. [Myrica asplenifolia L.]. 



69. Salicaceae Lindl. — Willow Family 



1. Catkin-scales fimbriate; leaves mostly broad, long-petioled; buds with 

 several scales 1. Populus 



1. Scales entire; leaves usually narrow and short-petioled; bud-scale one 



2. Salix 



1. Populus L. — Poplar 



1. Petioles terete or nearly so, not strongly flattened laterally. 

 2. Buds small, pubescent or glabrous, not viscid. 



3. Leaves sinuate-dentate to lobed; capsules 2-4 mm long; 

 catkin-scales fringed with silky hairs; stigmas linear; bark 

 smooth, whitish-gray, rough only at the base of old trunks; 

 introd. species. 

 4. Leaves persistently densely white-tomentose beneath, 3- to 

 5-lobed or irregularly dentate; buds copiously white- 

 tomentose; stigmas yellow; roadsides and yards, often 

 escaped from cult. ; introd. from Eurasia. Apr. White 



Poplar P. alba L. 



4. Leaves glabrous at maturity, gray-canescent beneath when 

 young, glabrate, the margins sinuate-dentate; bud-scales 

 ciliate or finely pubescent; stigmas purple; introd. from 

 Eur.; cultivated, and persisting in a few places. Gray 



Poplar P. cancscens (Ait.) Sin. 



3. Leaves crenate-serrate, ovate, cordate at base, long-petioled, 

 tomentose when young, becoming glabrous or remaining 

 floccose beneath: bark fuiTowed; capsules 7-9 mm long; 

 catkin-scales glabrous; stigmas broad; bordei^s of swamps, 



s. 111., local; Apr.-May. Swamp Cottonwood 



P. hetcrophylla L. 



2. Buds (at least the terminal) elongated, pointed, glabrous, glossy, 

 resinous-aromatic; leaves ovate-lanceolate, pale beneath, 

 crenu late-serrate; bark smooth; capsules on short stout ped- 



