53. ROSACEAE 113 



1. Leaves tomentose beneath; follicles pubescent; wet ground; Cook, 



Iroquois, Kankakee, and Lake counties. Hardback 



S. tomentosa L. 



3. Aruncus Adans. — Goat's-beard 

 A. dioicus (Walt.) Fern. Wooded ravines, May-June. Of local 

 occurrence throughout most of 111., but apparently absent from the 

 northeastern counties. [A. Sylvester sensu auth., non Kostel.; A. puhes- 

 cens Rydb. ; A. allegheniensis Rydb.]. 



4. Gillenia Moench — Indian Physic. American Ipecac 

 G. stipulata (Muhl.) Trel. Rich woods; extending northward to 

 La Salle Clo. ; more frequent southward. June- July. 



5. Fragaria L. — Strawberry 



1. Robust, thick-leaved garden plants, often 20-40 cm tall, sometimes 

 escaped from cult, to roadsides and waste places; petals 9-12 

 mm long; fruit ovoid-globose, 2-3 cm in diameter; achenes set 



in shallow pits. May. Cultivated Strawberry 



F. chiloensis X virginiana Duch. 



1. Native wild plants; fruit 6-15 mm in diameter; plants usually 

 smaller. 

 2. Leaflets finn, dull green above, petiolulate; flowers in coi-ymbs; 

 petals 5-10 mm long; fruit ovoid or subglobose, 1-1.5 cm in 

 diameter at maturity, the achenes set in pits; calyx-lobes not 

 reflexed; grassy banks and roadsides, or in open woods, very 

 common. Apr. -June. Wild Strawberry. [F. grayana Vilm.] 



F. virginiana Duch. 



2. Leaflets thin, light green, subsessile; inflorescence irregular, the 

 branches unequal; petals 3-6 mm long; fruit ovoid or conical, 

 6-9 mm in diameter, 1-1.5 cm long, the calyx-lobes spreading 

 or reflexed ; achenes superficial ; rocky banks and open woods, 

 in the n. half of 111. May-June F. americana (Porter) Britt, 



6. Potentilla L. — Cinquefoil 



1. Shrubs 30-100 cm tall, the bark shreddy; leaflets 5-7, elliptical, 

 1-2 cm long, silky-pubescent, the margins entire, revolute; 

 flowers 1.5-3 cm broad, yellow; in swamp, sandy, or limy soil, 

 Cook, Jo Daviess, Kane, and Lake counties. June- Aug. Shrub- 

 by Cinquefoil P. jruticosa L. 



1. Herbs; leaflets not entire. 



2. Petals maroon-purple, acute, shorter than the sepals; leaves 

 pinnate, 5- to 7-foliolate, the leaflets oblanceolate, serrate, 

 3-8 cm long, glaucous beneath; receptacle becoming spongy; 

 bogs and swamps; Cook, Lake, and McHenry counties. June- 

 July. Purple Cinquefoil P. palustris (L.) Scop. 



