53. ROSACEAE 115 



filiform, not glandular; stamens about 20; road- 

 sides and waste places, occasional; adv. from Eur. 



June-Aug P. intermedia L. 



6. Flowers solitary, axillai^, long-peduncled, 10-15 mm in 

 diameter; leaflets 5, oblanceolate, serrate; stem slender, 

 ascending or trailing; roadsides, gravelly soil, etc., com- 

 mon. May- June. [P. canadensis of auth. ex p.; P. 

 simplex var. argyrisma Fern. J Common Cinquefoil 

 P. simplex Michx. 



7. Filipendula Mill. 

 F. rubra (Hill) B.L.Robins. Queen-of-the-Prairie. Moist ground, 

 not common; n. 111. June- July. 



8. Geum L. — Avens 

 1. Petals yellow or white. 



2. Receptacle stalked in the calyx; petals yellow, 2 mm long; 

 fruiting heads at maturity about 1 cm in diameter; achenes 



puberulent; woods, common. Apr. -May. Spring Avens 



G. verum'lRsiL) T. & G. 



2. Receptacle sessile; calyx with 5 bractlets alternating with the 

 sepals. 



3. Petals white or pale yellow, shorter than or equalling the 

 calyx. 

 4. Peduncles slender, softly puberident, sometimes with a few 

 longer, scattered hairs; receptacle \illous or hirsute. 

 5. Stem sparingly pubescent to glabrous; petals white, 3-5 

 mm wide, 5-10 mm long, equalling or shorter than 

 the calyx-lobes; woods, thickets, and roadsides, com- 

 mon. June-Aug. White Avens G. canadense Jacq. 



5. Stem at least near base (and petioles) more or less 

 densely pubescent with spreading or retrorse hairs 

 about 2 mm long; petals pale yellow, 1-2 mm wide, 

 2-4 mm long, much shorter than the calyx-lobes; dry 



woods, s. 111., apparently not common. Jime-July 



G. viriiinianum L. 



4. Peduncles stouter, hirsute with spreading hairs 1-2 mm 

 long; petals white, 3-5 mm long, much shorter than the 

 calyx-lobes; receptacle glabrous or nearly so; stem hir- 

 sute; wet ground in woods and thickets. June- July. 

 \G. virginianum sensu auth., non L.] ....G. laciniatum Murr. 

 3. Petals golden yellow, 5-10 nun long, exceeding the sepals; 

 receptacle pubescent; moist thickets and roadsides in the 



northern counties. June-July. Yellow Avens 



G. strictum Ait. 



1. Petals purplish. 



