146 EOSACEAE. 



Style terminal or nearly so. 



Pistils numerous : ovules pendulous : plants 



caulescent. 9. POTENTILLA. 



Pistils 2-6 : ovules erect : plants acaulescent. 10. WALDSTEINIA. 

 Style persistent on the achene. 

 Pistils numerous. 



Head of achenes stipitate : sepals without 



bractlets. 11. STYLIPDS. 



Head of achenes sessile : sepals accompanied 



by bractlets. 12. GEUM. 



Pistils 5-15, at maturity resembling follicles, but 



indehiscent. 13. FILIPENDULA. 



Fruit consisting of several achenes enclosed in the persistent 



hypanthium. 

 Achenes 1-4 within the dry hypanthium. 



Receptacle bearing hooked prickles : petals 5. 14. AGRIMONIA. 



Receptacle without prickles : petals wanting. 15. SANGTJISORBA 



Achenes numerous, within the fleshy hypanthium. 16. ROSA. 



1. OPULASTER Medic. Shrubs. Leaf -blades palmately lobed. Flowers 

 corymbose. Corolla white. Stamens numerous, without staminodia. Carpels 

 1-5, short-stipitate : styles filiform: stigmas depressed-capitate. Follicles in- 

 flated. 



1. O. opulifolia (L.) Kuntze. Shrub 1-3 m. tall: leaf -blades 3-8 cm. long, 

 acutely lobed: sepals ovate, 2.5-3.5 mm. long: follicles 8-10 mm. long, acute. 

 Common, in thickets near streams. Spr. NINEBARK. 



2. SPIRAEA [Tourn.] L. Shrubs. Leaf -blades toothed or lobed. Flowers 

 corymbose or paniculate. Corolla white, pink or rose. Stamens numerous, 

 accompanied by lobe-like staminodia. Carpels usually 5, mostly stipitate: 

 styles clavate: stigmas minute and oblique. Follicles not inflated. SPIRAEA. 



Inflorescence pyramidal : mature hypanthium campanulate or hemispheric. 



Plant glabrous : follicles glabrous. 1. S. latifolia. 



Plant pubescent: follicles tomentose. 2. 8. tomentosa. 



Inflorescence corymbose : mature hypanthium flat. 3. 8. japonica. 



1. S. latifolia (Ait.) Borkh. Plants 3-12 dm. tall: leaf -blades thinnish, gla- 

 brous or nearly so beneath: flowers slender-pedicelled : sepals not ciliate: 

 petals white, 2-2.5 mm. wide: carpels and follicles glabrous, the latter 3-3.5 

 mm. long. Common, in swamps and wet meadows. Spr. and sum. 

 MEADOW- SWEET. 



2. S. tomentosa L. Plants 3-15 dm. tall: leaf -blades thick, tomentose be- 

 neath: flowers stout-pedicelled : sepals ciliate: petals rose-colored, 1-1.5 mm. 

 wide: carpels and follicles pubescent, the latter 2-2.5 mm. long. S. Eare, in 

 swamps. Schists. Sum. HARDBACK. STEEPLE-BUSH. 



3. S. japonica L. f. Plants 1-2 m. tall with finely pubescent twigs: leaf -blades 

 oblong, elliptic, or oblong-lanceolate, 3-12 cm. long, acuminate, finely pubes- 

 cent at least when young, irregularly serrate, cuneate at the base: corymbs 

 many-flowered, round-topped: sepals deltoid, fully 1 mm. long, acute: petals 

 pink or rose-colored, suborbicular, 1.5-2 mm. long, or rarely longer: follicles 

 erect, about 3 mm. long, glabrous. S. Eare, in thickets. Nat. of Japan. 

 Sum. 



3. PORTERANTHUS Britton. Perennial herbs. Leaf -blades 3 -parted 

 or 3-foliolate. Flowers perfect few borne in open lax panicles. Sepals shorter 

 than the hypanthium. Petalsi narrow, white or pink. Stamens numerous, in 

 one row on the hypanthium: filaments very short. Carpels mostly 5: styles 

 subulate. Follicles erect. 



1. P. trifoliatus (L.) Britton. Plants 3-12 dm. tall: leaflets 3-9 cm. long; 

 blades acuminate, sharply serrate, thin: sepals glandular-serrulate: petals 



