136 WEEDS OF THE FARM AND GARDEN 



Flowers with sepals, embryo straight (Polygonaceae). P. 162. 

 Flowers without floral envelopes (Piperaceae). P. 160. 

 9. Fruit, an utricle 10 



10. Flowers, with bracts (Amaranthaceae). P. 170. 



Flowers, without bracts 1 1 



11. The persistent calyx inclosing the fruit (Nyctagineaceae). P. 162. 

 Calyx not persistent; sepals green or greemsh(C/ienopodiaceae.) 



P. 167. 



12. Flowers, polypetalous 13 



Flowers, gamopetalous 27 



13. Stamens numerous 14 



Stamens few, as many as the petals, or not more than twice as 



many 20 



14. Calyx free from the ovary; pistil, one or more than one 15 



15. Pistils numerous, or more than one 16 



I istils, one or few 17 



1 6. Stamens inserted on the calyx (Rosaceae). P. 185. 



17. Stamens, monadelphous or diadelphous. 

 Fruit a legume (Leguminosae). P. 187. 

 Pistils united into a ring (Malvaceae). P. 136. 



Stamens, not monadelphous 19 



18. Stamens inserted on the receptacle, leaves not punctate (Ra- 



nunculaceae). P. 177. 



Stamens inserted on the receptacle in clusters, leaves punctate, 

 flowers yellow (Hypericaceae). P. 202. 



19. Ovary compound, one-celled ; fleshy herbs (Portulacaceae). P. 176. 

 Ovary compound; pistil one, carpels two or more; plants with 



milky or colored juice (Papaveraceae). P. 178. 



20. Calyx free from the ovary 21 



21. Ovary i, 2 4-lobed, or entire (Sapindaceae). P. 198. 



Ovary 2 5, or more, celled 22 



22. Leaves dissected (Geraniaceae). P. 191. 

 Leaves trifoliate (Oxalidaceae). P. 191. 



Leaves pinnately compound (Zygophyllaceae). P. 192. 



Ovary compound, one-celled 23 



Ovary compound, two or more celled 25 



23. Flowers, irregular, stamens five (Violaceae). P. 203. 



Flowers, regular 24 



24. Flowers, perfect, regular (Caryophyllaceae). P. 173. 

 Flowers, monoecious or dioecious (Euphorbiaceae). P. 193. 



25. Ovules, solitary, trees or shrubs (Anacardiaceae). P. 198. 

 Ovules few, stamens six, tetradynamous (Cructferae). P. 179. 

 Ovules few, stamens six, not tetradynamous (Capparidaceae). P. 184. 



26. Ovary 2 to several-celled, stamens 8 or 4 (Onagraceae). P. 204. 

 Ovules and seeds, only one in each cell, stamens five, flowers 



in umbels (Umbelltferne)* P. 205. 



27. Calyx free from the ovary, superior 28 



28. Corrlla, regular 29 



Corolla, irregular 35 



29. Ovaries of two carpels 30 



