39 



SUBORDER ROSACES. 



2. Spirae'a. Carpels mostly 5, forming follicles in fruit. Calyx 5-cleft, saoit. 



Petals obovate, similar. 



3. Gille'nia. Carpels and f ruit as in Spiraea. Calyx elongated, 5-toothed 



Petals slender, dissimilar. 



4. Agrimo'nia. Carpels 2, forming achenes enclosed in the hardened calyx- 



tube. Calyx armed with hooked bristles. Flowers yellow, in slender 

 spikes. 



5. Geuin. Carpels numerous, one-ovuled, becoming dry achenes, the per- 



sistent styles becoming tails, plumose or naked, and straight or jointed. 

 Calyx-lobes with 5 alternating bractlets. 



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



form leaflets. Bractlets of the calyx minute and deciduous. Flowers 

 yellow, on bractcd scapes. 



7. Poteiitil'la. Carpels numerous, forming achenes heaped on a dry recep- 



tacle, the styles not forming tails. Lobes of the calyx with 5 alternating 

 bracts. 



8. Fraga'ria. Flowers as in Potentilla, but receptacle becoming fleshy or 



pulpy and scarlet in fruit. (See Part I., section 235.) Leaves all radical, 

 of 3 leaflets. Low plants producing runners. 



9. Dalibar'cla. 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. 



10. Kubus. Carpels numerous, 2-ovuled, forming drupelets heaped on the 



receptacle. (See Part I., section 234.) Fruit edible. Calyx without 

 bracts. 



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



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



SUBORDER POME.ZE. 



12. Cratse'gus. 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. 



13. Pyrus. 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. 



14. Amelan'chier. Pome berry-like, 10-celled, i.e., with twice as many 



cells as styles. Petals narrow. Otherwise as in Pyrus. Shrubs or small 

 trees, not thorny. 



1. PRUNUS, Tourn. PLUM. CHERRY. 



1. P. Amerca'na, Marshall. (WILD PLUM.) A thorny tree 

 8-20 feet high, with orange or red drupes half an inch or more in 



