MEMOIRS FROM THE DEPARTMENT OF BOTANY OF COLUMBIA UNIVERSITY 19 
my specific lines are nearly the same as those of Professor Greene.’ In addition I have 
described a few new species and have made a few necessary changes. 
KEY TO THE GENERA. 
Style terminal or nearly so ; ovules pendulous and anatropous. 
Hypanthium saucer-shaped to deeply campanulate ; petals oblanceolate to 
obeordate. 
Anthers oblong, opening by longitudinal slits; pistils several to many, 
very rarely one. 
Stamens inserted very near the base of the receptacle on a more or 
less evident annular thickening. 1. Potentilla. 
Stamens separated from the receptacle by a w ide open space ; no in- 
dieation of an annluar thickening. 2. Horkelia. 
Anthers obeordate, opening by subterminal pores ; pistils 1. 3. Stellariopsis. 
Hypanthium wheel-shaped ; petals narrowly linear ; pistils 2. 4. Comarella. 
(Style terminal, ovules basal, erect. Waldsteinia.”) 
Style lateral ; ovules ascending and amphitropous. 
Achenes glabrous ;_ herbs. 
Achenes numerous ; stamens 20. 
Receptacle not enlarged in fruit ; leaves interruptedly pinnate; flowers 
yellow. 5, Argentina. 
° 
Receptacle in fruit somewhat enlarged and spongy ; leaves pinnate ; 
petals red. 6. Comarum. 
Receptacle much enlarged and red in fruit ; leaves trifoliolate. 
Receptacle not pulpy ; petals yellow. 7. Duchesnea. 
Receptacle pulpy, edible ; petals white or pinkish. 8. Fragaria. 
Achenes 10-15 ; stamens 5 ; leaves trifoliolate. 9. Sibbaldia. 
Achenes hairy ; shrubs. 
Leaves trifoliolate ; style filiform ; flowers white. 10. Sibbaldiopsis. 
Leaves pinnate ; style club-shaped ; flower (in ours) yellow. 11. Comocarpa. 
Style nearly basal ; ovules ascending or nearly erect, orthotropous. 
Stamens and pistils numerous ; bractlets present ; leaves pinnate ; flowers 
large. 12. Drymocallis. 
Stamens 5; pistils 5-10 ; bractlets not present ; leaves twice ternate ; flowers 
small. 13. Chamaerhodos. 
1 Pittonia, 1: 95-106. 
2 Waldsteinia and the Siberian Coluria are sometimes placed in the Potentilleae on account of the styles which are articu- 
lated to the ovary, sometimes in the Dryadeae on account of their basal erect ovules. 
