ROSACES. 63 



6. Pote'rlnm. Carpels 1-3. Achene (mostly solitary) enclosed in the 



dry 4-angled closed calyx-tube. Petals none. Lobes of the top- 

 shaped calyx 4, petal-like, spreading. Stigma tufted. Tall herbs, 

 with pinnate leaves and a dense white spike of small flowers, often 

 polygamous or dioecious. 



7. Geum. Carpels numerous, one-ovuled, becoming dry achenes, the 



persistent styles becoming tails, plumose or naked, and straight 

 or jointed. Calyx-lobes with 5 alternating bractlets. 



8. Waldstei'nia. Carpels 2-6, forming achenes. Leaves radical, of 3 



wedge-form leaflets. Bractlets of the calyx minute and deciduous. 

 Flowers yellow, on bracted scapes. 



9. Potentll'la. Carpels numerous, forming achenes heaped on a dry 



receptacle, the styles not forming tails. Lobes of the calyx with 

 5 alternating bractlets. 



10. Chamae'rliodos. Carpels 5-10, on a dry receptacle. Petals white, 



obovate. Stamens 5, opposite the petals. Calyx campanulate, 5- 

 cleft. Small glandular-pubescent herbs with flowers in forked 

 cymes, and many-cleft leaves. 



11. Fraga'rla. Flowers as in Potentilla, but receptacle becoming 



fleshy or pulpy and scarlet in fruit. (See Part I., sec. 235.) Leaves 

 all radical, of 3 leaflets. Low plants, producing runners. 



12. Dallbar'da, Carpels 5-10, each 2-ovuled, forming nearly dry 



drupelets. Calyx 5-6-parted, 3 of the divisions larger than the 

 others, and toothed. Calyx without bracts, persistent, enclosing 

 the fruit. Leaves radical, round heart-shaped. Flowers white, 

 on scapes. 



13. ItulMis. Carpels numerous, 2-ovuled, forming drupelets heaped on 



the receptacle. (See Part I., section 234.) Fruit edible. Calyx 

 without bracts. 



14. Rosa. Carpels numerous, 1-ovuled, forming achenes enclosed in 



the fleshy calyx-tube. (See Part I. , section 49.) 



SUBORDER POME.E. 



Carpels enclosed in and adnate to the fleshy calyx-tube, 

 forming a pome in fruit. Styles often united below. Trees 

 or shrubs. 



15. Cratse'gua. Calyx-tube urn-shaped, becoming thick and fleshy in 



fruit, enclosing and combined with the 2-5 carpels. Fruit a pome, 

 but drupe-like, containing 2-5 bony nutlets. Thorny shrubs. 

 Flowers generally white. 



16. Pyrns. Fruit a pome or berry-like, the 2-5 carpels or cells of a 



papery or cartilaginous texture (see Part I., sections 52 and 232), 

 each 2-seeded. Shrubs or trees. 



