238 American Midland Naturalist Monograph No. 2 



2. Leaves coarsely dentate, the veins straight, ending in the teeth; petioles 

 not margined; cymes peduncled. 



5. Leaves short-petioled, the petioles not more than 1 cm. long; blades 

 usually with 7-10 teeth on each side; fruit ellipsoid, the stone flat- 

 tened, sulcate on both sides. 

 6. Lower surface of leaves softly pubescent over the whole surface; 

 woods and river banks, n. 111., not common; known from Lake, 

 Cook, Du Page, McHenry, Winnebago, and Jo Daviess counties. 

 May-June. [V. villosuyn Raf. not Sw.; V. pubescens of auth., not 



Pursh; V. affine var. hypomalacum Blake] 



V . rafinesquianum Schult. 



6. Lower surface of leaves glabrous, except on the veins or in their axils; 

 woods and thickets, locally throughout the n. half of the state 

 from Vermilion and Peoria counties northw. May-June. [F. pu- 

 bescens var. affine (Bush) Rehd.; V. rajinesquiajium var. affine 

 (Bush) House] V. affine Bush 



5. Leaves longer-petioled, the petioles 1-2.5 cm. long; blades usually with 

 10-15 teeth on each side; fruit globose-ovoid, the stone deeply sulcate 

 ventrally, the back rounded; woods, rare. [F. pubescens var. deamii 

 Rehd.; V . pubescens var. indianense Rehd.; V . dentatum var. deamii 

 (Rehd.) Fern.] V. dentatum L. 



1. Leaves palmately veined, usually 3-lobed. 



7. Young twigs glabrous; petioles glabrous and with a pair of glands; mar- 

 ginal flowers of the cyme neutral, with enlarged flat corollas; fruit red; 

 moist woods, chiefly in the n. half of the state. May-June. American 



Cranberry-bush. [V . opulus var. americanuyn (Mill.) Ait.] 



V . trdobum Marsh. 



7. Young twigs pubescent; petioles pubescent, glandless; cyme with all the 

 flowers alike and perfect; fruit black; dry woods, chiefly in the n e. 

 counties. May-June. Maple-leaved Viburnum V. acerijolium L. 



3. Symphoricarpos Duham. — Snowberry 



1. Corolla 5-9 mm. long; fruit white or greenish white. 



2. Stamens and style included; twigs and leaves glabrous; petioles 2-4 mm. 

 long; corolla 5-7 mm. long; style 2 mm. long, glabrous; fruits white, 

 the larger ones 12-15 mm. in diameter; native of w. N. Am. and com- 

 monly planted for ornament, but scarcely established in 111. Garden 

 Snowberry. \_S. racemosus of auth., not Michx.; S. racemosus var. 

 laevigatus Fern.] S. rivularis Suksd. 



2. Stamens and style shortly exserted; twigs puberulent; leaves pubescent; 

 petioles 4-10 mm. long; corolla 6-9 mm. long; style 4-8 mm. long, 

 pilose or glabrous; fruits pale greenish white, 6-8 mm. in diameter; dry 

 soil, n. 111., rare, extending southw. to Kankakee and Hancock counties. 



June-July. Wolfberry S. occidentalis Hook. 



1. Corolla 3-4 mm. long; fruit red (rarely whitish), ellipsoid, glaucous, 5-7 

 mm. long; stamens and style included; style 2 mm. long; petioles 2-4 mm. 



