Platanus 



ROSACEAE 



Platanvs 



AA. 



BB. Hypanthium shallow and with a central column, or deep and 

 urn-shaped. III. Rosoideae. 



D. Petals none; flowers in dense cylindric spikes 5. 



DD. Petals present; flowers not in cylindric spikes. 

 E. Hypanthium shallow, with a central column. 

 F. Lvs. simple. 



Fls. white : leaves opposite 6. 



Fls. yellow: leaves alternate 7. 



FF. Lvs. compound. 



G. Style deciduous, not elongating in fr. 



H. Fr. dry. 



Achenes two, enclosed in a dry hardened 

 calyx tube bearing a row of hooked 

 bristles at the top: fls. in long ra- 

 cemes 8. 



Achenes many, not enclosed: fls. solitary, 



or in cymes 9. 



HH. Fr. fleshy. 



Column of the hypanthium greatly en- 

 larged in fr.: herbs. 

 Hypanthium very fleshy: flowers white. . 10. 

 Hypanthium rather pithy: flowers yel- 

 low 11. 



Column of the hypanthium not greatly 

 enlarged, shrubs, mostly armed with 



spines or prickles 12. 



GG. Style persistent, elongating in fr 13. 



EE. Hypanthium urn-shaped, enclosing the achenes: mostly 



prickly shrubs 14 . 



Fls. epigynous: fr. a pome. IV. Pomoideae. 

 I. Fr. with stony carpels. 



Stony carpels 2-seeded. 



Plants without thorns: leaves entire 15. 



Plants thorny: leaves crenulate 16. 



Stony carpels 1-seeded 17. 



II. Fr. with leathery or papery carpels. 

 J. Carpels of the fr. several-seeded. 



Fls. appearing with the lvs.; styles free: lvs. entire 18. 



Fls. appearing before the lvs; styles connate at the base: 



lvs. serrate or crenate 19. 



JJ. Carpels of the fr. 1-2-seeded. 



K. Carpels joined together: fr. very fleshy 20. 



KK. Carpels more or less free. 



L. Infl. compound, often flat-topped. 



Fr. open at the top 21 . 



Fr. closed at the top 22. 



LL. Infl. simple, racemose or umbellate. 



Ovary and fruit 2-5-celled; cells 2-ovuled. 



Fr. usually apple-shaped: grit cells few or none: 



styles united at the base 23. 



Fr. usually pear-shaped: grit cells numerous: 



styles distinct to the base 24. 



Ovary and fruit incompletely 6-10-celled; cells 1- 

 ovuled 25. 



156 



Sanguisorba 



Rhodotypus 

 Kerria 



Agrimonia 

 Potentilla 



Fragaria 

 Duchesnea 



Rubus 

 Geum 



Rosa 



Cotoneaster 

 Pyracantha 

 Crataegus 



Cydonia 



Chaenomeles 



Eriobotrya 



Photinia 

 Sorbus 



Mains 

 Pyrus 

 Amelanchier 



