14 CONTEIBUTIONS FEOM THE NATIONAL HEKBAEIUM. 



Flowers not in involucrate heads. 



Fruit either a berry or a drupe or nuth'ke. 



Stamens as many as the perianth segments and alternate 

 with them or else fewer. 

 (Tetragoniaceae) 24. CHENOPODIALES (p. 198). 

 Stamens as many as the perianth segments and opposite 

 them or else twice as many. 



(Families of) 37. MYRTALES (p. 459). 

 Fruit a capsule. 



Sepals as many as the cells of the ovary or half as many. 



37. MYRTALES (p. 459). 

 Sepals (4 or 5) at least twice as many as the cells of the 



ovary (Saxifragaceae) 27. ROSALES (p. 291). 



Ovary superior. 



Gynoecium of 1 carpel or several distinct carpels; stigma and styles 

 of each solitary. 

 Carpels several. 



Stamens inserted below the ovary. 



(Families of) 25. RANALES (p. 243). 

 Stamens inserted on the edge of a cup-shaped hypanthium. 



(Families of) 27. ROSALES (p. 29-1). 

 Carpels solitary. 



Style lateral and oblique. 



(Phytolaccaceae) 24. CHENOPODIALES (p. 198). 

 Style axile, erect. 



Ovary neither inclosed nor seated in a hypanthium or a 

 calyx tube. 

 Flowers solitary in the axils of the leaves; aquatics. 

 (Ceratophyllaceae) 25. RANALES (p. 243). 

 Flowers not solitary in the axils of the leaves; terres- 

 trial plants. (Urticaceae) 20. URTICALES (p. 174). 

 Ovary inclosed in or seated in a hypanthium or a calyx 

 tube. 

 Stamens borne under the gynoecium. 



(Allioniaceae) 24. CHENOPODIALES (p. 198). 

 Stamens borne on the hypanthium or adnate to the 



calyx tube 36. THYMELAEALES (p. 458). 



Gjmcecium of 2 or several united carpels; stigmas or styles 2 to 

 several. 

 Ovary, by abortion, 1-celled and 1-ovuled. 

 Leaves with sheathing stipules. 



23. POLYGONALES (p. 181). 

 Leaves exstipulate, or the stipules, if present, not sheathing. 



Trees or shrubs (Ulmaceae) 20. URTICALES (p. 174). 



Herbs or vines. 

 Stipules herbaceous; inflorescence spicate or racemose; 

 leaf blades palmately veined. 



(Cannabinaceae) 20. URTICALES (p. 174). 

 Stipules scarious or hyaline or none; inflorescence 

 cymose; leaf blades pinnately veined. 



(Families of) 24. CHENOPODIALES (p. 198). 



Ovary several-celled, or with several placentas, several-ovuled. 



Stamens perigynous or epigynous, inserted on the margin 



of a hypanthium or a disk. 



Fruit a samara... (Aceraceae) 31. SAPINDALES (p. 405). 



