ROSACEA. 165 



TuiRi: I. SriR^ACEiE. Carpels few, rarely solitary, becoming 2 - several-sculni follicles 

 (dehiscent jjocIs). Calyx open. 



3. Spiraea. Follicles 2 to 8. Seeds pendulous, linear ; the coat membranaceous : albumen 



none. Shrubs or herbs, with simple or compound leaves, and compound inflorescence. 



4. Neillia. Follicles 1 to 5. Seeds erect and pendulous ; the coat crustaceous, shining : albu- 



men present. Shrubs, with simple leaves : corymbs simple. 



Tninr, II. RUliEyE. Carpels several or numerous on a spongy receptacle, becoming drupe- 

 lets in fruit. Calyx open, without bractlets. Stamens numerous. Ovules 2 and pen- 

 dulous, but seed Bolitiuy. 



5. RubuB. Carpels iudofiuitcly numerous, berry-like in fruit. Perennial hcrb.s, or 8oft-woo<ly 



shrubs with biennial stems. 



TlilBR III. DRYADE^. Carpels numerous, .several, or solitarj', 1-ovuled, becoming dry 

 akenes. Calyx not enclosing or at least not constricted over the fruit. Seed erect or 

 ascending. 



* Shrubs : carpels mostly solitary : style not elongated in fruit : stigma decurrent : calyx imbri- 



cated, without bractlets : radicle inferior (except in Cohogyne). 



fi. Chamaebatia. Flowers corymbose. Petals 5. Tjcavos thrico pinnate, with minute leaflets. 



7. Purshla. Khiwers .TOlitarjr. Potnls fi. Lenvos 3-clnft. 



8. Coleogyne. F]<iwors solitary. Calyx 4-partod, colored. Petals none. Leaves opposite, 



.small, narrow, entire. 



* * Trees or shrubs : carpels solitary or numerous : styles elongated and plumose in fruit : calyx 



imbricated, without bractlets (except in Fallugia) : seed erect. 



9. Cercocarpua. Flowers solitary, axillary, small. Petals none. Carpels solitary, rarely 2. 



(^alyx-tubo long-cylindrical ; the limb deciduous. Leaves simple, entire or toothed. 



10. Co^wania. Flowers solitary, short-peduncled, terminal, showy. Petals 5. Carpels 5 to 12. 



("nlyx short and turbinate. Leaves cuneate, lobed. 



11. Fallugia. Flowers somewhat pani(ded, on long peduncles, showy. Petals 5. Carpels nu- 



merous. Calyx turbinate. Leaves with linear lobes. 



* * * Herbs: carpels few to many : calyx concave or campanulate, valvate in the bud, bracteolate. 

 +- Seed erect from the base of the cell : radicle inferior : style strictly terminal, persistent. 



12. Geum. Carpels very numerous on a dry receptacle : the elongated style in fruit mostly 



geniculate or plumose. 



+- +- Seed suspended or ascending : radicle superior : style small, naked, not geniculate. 



13. Fragaria. Carpels very iiuinernus, in fruit on a large flesliy scitrlot receptacle. Styles 



liil(^nil. Leaves 3-foli()late. 

 11. PotentlUa. Petals yellow, raiely white, sessile. Stamens usually 20 or more; lilamonta 

 narrow or lililbrm. (darnels mostly numerous, on a dry recei)tiiclo. Leaves jiiunato or 

 digitate ; leadots tootheu or cleft, not confluent. 



15. Sibbaldia. Petals yellow, sessile, minute and narrow. Stamens 5 ; filaments very short, 



filiform. Carpels 5 to 10, on a dry receptacle. Leaves 3-foliolate ; leaflets 3-toothed. 



16. Horkelia. Petals white or pink, with claws, or spatulate. Stamens 10, rarely 20 ; fila- 



ments usually dilated or subulate. Carpels usually many, on a dry nearly naked recep- 

 tacle. Leaves pinnate ; leaflets many, toothed, cleft, or parted, the upper confluent. 



17. Ivesia. Petals white or yellow, with claws, or spatulate. Stamens 5 to 20 ; filaments fili- 



form. Carpels 1 to 15, on a dry villous receptacle. Leaves pinnate ; leaflets cleft or 

 parted, often small and very numerous and closely imbricated. 



Tribe IV. POTERIE/E. Carpels 1 to 3, in fruit akenes, completely enclosed in the dry and 

 firm calyx-tube, the throat of which is constricted or sometimes nearly closed. Seed 

 suspended. 



* Heath-like shrubs, with simple entire fascicled leaves : ovules 1 or 2. (Anomalous genus.) 



18. Adenostoma. Calyx lO-nerved, at length cylindraceous. Petals 5. Stamens 8 to 15. 



♦ • Hcrks (as to ours), with conipounil or lobed leaves : ovnlo solitary. 



19. Alohemilla. Calyx naked, urceolato, minutely bracteolate. Petals none. Stamens 1 to 4. 



Flowers minute, clustered. 



20. Agrimonia. Calyx turbinate, surrounded by a margin of hooked nrickles. Petjils yellow. 



Stamens 5 to 12. Tall porojuiial herbs, with pinnate leaves and long racemes. 



