ROSACEAE 525 



Leaves pinnate, 1.5-3.5 cm long, silky-pubescent beneath; flowers yellow; fruit 



a head of many achenes 3356. Potentilla, p. 565. 



Leaves pinnate or 3-5-foliolate, not silky-pubescent beneath; flowers white; fruit 

 a reddish pome or a cluster of reddish or reddish purple drupelets. 

 Leaves pinnate, 10-16 cm long; leaflets generally 13-17; fruit a reddish pome. . 



3338B. Sorbus, p. 529. 



Leaves 3-5-foliolate; small herbaceous or semi- woody plants of a decumbent 

 or trailing habit, of a wet or bog habitat; fruit small, usually consisting 



of fewer than 15 drupelets 3353. Rubus pubescens, p. 558. 



Plants herbaceous. 



Fruit juicy, white or reddish purple; leaves 3-5-foliolate. 



Fruit on naked scapes, red or white 3354. Fragaria, p. 563. 



Fruit terminal or in the axils of leaves. 



Calyx with 5 large bracts; petals yellow; fruit red, strawberrylike 



3355. Duchesnea, p. 564. 



Calyx not bracted; petals white; fruit an aggregate of drupelets (drupelets 

 usually fewer than 15), reddish purple. . . .3353. Rubus pubescens, p. 558. 

 Fruit dry. 



Plants stemless or nearly so; leaves appearing to be all basal, trifoliate; flowers 



scapose, yellow; carpels few, generally 2-6, rarely up to 10, 1-ovuled 



3363. Waldsteinia, p. 568. 



Plants not as above. 



Flowers white in one or more long, terminal spikes or the spikes in large, 



terminal panicles, or greenish in dense, peduncled heads; leaves pinnately 



divided into 7-19 leaflets or twice or thrice pinnate; fruit a short follicle 



or an achene enclosed by the 4-angled calyx tube. 



Leaves once pinnate; leaflets serrate or incised; flowers white in long 



(5-15 cm), terminal spikes or green with purple stigmas in dense, 



peduncled heads; fruit an achene enclosed by the calyx tube 



3381. Sanguisorba, p. 573. 



Leaves ternately twice or thrice pinnatifid; leaflets ovate-oblong, long- 

 acuminate at the apex, sharply doubly serrate; flowers in spikes ar- 

 ranged in a large, open, terminal panicle; fruit of 2 or 3 glabrous 



follicles 3322. Aruncus, p. 527. 



Flowers and inflorescence not as in the two preceding. 



Calyx bracteolate, the bracts alternate with the calyx lobes. 



Styles long, bent and jointed near the middle, at maturity the upper part 

 deciduous, the lower part persistent and hooked at the summit; 



flowers white, yellow or purple 3365. Geum, p. 568. 



Styles deciduous, not jointed or hooked; flowers yellow 



3356. Potentilla, p. 565. 



Calyx not bracteolate. 



Leaves trifoliate or the upper ones 3-lobed or simple on short petioles; 



petals white, about 1 cm long 3325. Gillenia, p. 527. 



Leaves pinnate; flowers many; petals yellow, pinkish or white, less than 

 1 cm long. 

 Flowers in large, cymose panicles, white or pink; fruit a 1-seeded 



indehiscent capsule 3374. Filipendula, p. 571. 



Flowers in spikelike racemes, yellow; fruit (the enlarged calyx tube 



enclosing the 2 achenes) with hooked bristles 



3376. Agrimonia, p. 571. 



3316. PHYSOCARPUS Maxim. 



Follicles glabrous or glabrate LP. opulifolius. 



Follicles more or less densely pubescent la. P. opulifolius var. intermedius. 



