ROSE FAMILY 117 



Hypanthium wheel-shaped; petals narrowly linear; 



pistils 2. 11- COiL\RELLA. 



Stamens inserted very near the base of the receptacle on 

 a more or less evident annular thickening. 



12. POTENTILLA. 



style lateral; ovxiles ascending and amphitropous. 

 Achenes glabrous; herbs. 



Achenes numerous; stamens about 20. 



Leaves odd-pinnate. . , . ^ , ,, 



Receptacle not enlarged m fruit; petals yellow, 

 obtuse or retuse; leaves interruptedly pm- 

 nate. 13. Argentina. 



Receptacle somewhat enlarged m fnnt, becom- 

 ing spongy; petals red, acute or acuminate; 

 leaves regularly pinnate. 



14. COMARUM. 



Leaves trifoliolate; receptacle much enlarged and 

 usually red in fruit, pulpy; petals wliite or 

 pinkish. 15. Fr.\garl\. 



Achenes 10-15; stamens 5; leaves trifoholate. 



16. SIBBALDIA. 



Achenes hairy; slirubs; style club-shaped; leaves pinnate; 



petals (in ours) yellow. 17. D.\siPHORA. 



Stvle nearly basal; ovules ascending or nearly erect, orthotropous. 



" Stamens and pistils numerous; bractlets present; leaves pm- 



nate 18. Drymocallis. 



Stamens 5; bractlets wanting; leaves twice or thrice ternate. 



19. CH-\1IAERH0D0S. 



St vie not articulate to the ovary; inflorescence spicate, racemose 

 or paniculate; hj-panthium indurate, closely mvestmg the 

 achenes in fruit. 

 Hj-panthium not prickly; petals lacking. 



Perennials, \\ith rootstocks; stigmas muncate-papiUose ; leaf- 

 lets toothed. 20. S.'U.GUISORBA. 

 Annuals or biennials, with taproots; stigmas brush-Like; leaf- 

 lets pectmate-pmnatifld. 21. POTERIDR-M. 

 H\-pantlilum prickly; petals present ; prickles of the hypanthium 

 ■ hooked ^ "^ 22. Agrimonia. 

 Disk at the mouth of the hypanthium produced into a cylmdric tube, 

 separatmg the stamens from the pistils; slirubs with opposite leaves 

 and branches 2.3. Coleogyne. 

 b. Seeds inserted at the proximal end of the ovary, i. e., perfectly basal; 

 radicle inferior. „ , .^ .„^„^ . 

 Styles wholly deciduous. 24. Waldsteixla.. 

 Styles partly or wholly persistent. ...... ■ 4. ^ 



Hypanthium hemispheric, campanulate or turbinate, persistent. 

 Pistils several or many. , i, i, -..i. 



Flowers 8-10-merous; low depressed undershrubs with cren- 



ate or entire leaf-blades. 25. Dryas. 



Flower usually 5-merous. ., , , 



Sepals valvate; perennial herbs, with rootstocks; leaves 

 pinnate; bractlets present. 

 Style conspicuously bent and distinctly geniculate 

 " above, the upper hairy portion readily deciduous. 

 26. Geum. 

 Style neither conspicuously bent nor distinctly geni- 

 culate, the upper glabrous portion persistent 

 or tardily deciduous. . 



Styles conspicuously elongating m fruit, plumose 



below. 27. Sieversia. 



Styles not much elongating in fruit, not plumose. 



28. Acomastylls. 

 Sepals imbricate in bud; shrubs; leaves dissected into 



narrow lobes. 

 Bractlets present; pistils numerous. 



29. Fallugia. 

 Bractlets wanting; pistils few. 30. Cowania. 



Pistils usually sohtary ; shrubs with 3-cleft leaves. 



31. PURSHIA. 



Hypanthium salver-shaped, the Umb deciduous; the tube persistent 

 and closely investing the fruit; shrubs. 32. Cercocarpus. 

 o. Fruits of more oi less fleshy drupelets; ovules 2, collateral. 



Styles club-shaped- stigmas slightly 2-lobed; receptacle flat; unarmed shrubs 

 with exfoUating bark and simply digitately ribbed and lobed leaves. 

 Drupelets capped by a hard pubescent cushion; styles glabrous. 



33. Rtjb.\cer. 

 Drupelets without cushion; styles hairy. 34. Oreobatus. 



Styles filiform, glabrous; stigmas capitate; receptacle convex, hemispheric or 

 nipple-shaped; drupelets without cushion; leaves in most species compouna 

 and stem prickly or bristly. 35. RUBUS. 



IL Carpels enclosed in the hypanthium which becomes fleshy in fruit. 



36. xvOSA. 



