16 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Ovary several-celled. 

 Upper portion of ovaries distinct. (Crassulaceae) 27. ROSALES (p. 291). 



Upper portion of ovaries united 41. EBENALES (p. 495). 



Stamens as many as the lobes of the corolla and alternate with them or fewer. 

 Corolla scarious, veinless; fruit a pyxis.. 46. PLANTAGINALES (p. 602). 

 Corolla not scarious, veiny; fruit not a pyxis. 

 Carpels distinct, except sometimes at the apex. 



Style terminal 44. ASCLEPIADALES (p. 503). 



Style basal (Dichondraceae) 45. POLEMONIALES (p. 513). 



Carpels united. 

 Ovary 1-celled, with central placentae. . .43. GENTIAN ALES (p. 497). 

 Ovary 2 or 3-celled or falsely 4-celled, or if 1-celled with parietal 



placenta; 45. POLEMONIALES (p. 513). 



Petals distinct, at least at the base. 

 Carpels solitary, or several and distinct, or united only at the base. 



Stamens on the margin of a hypanthium (this very small in some Saxifragaceae). 



27. ROSALES (p. 291). 

 Stamens at the base of the receptacle, hypogynous. 



Flowers in monoecious heads (Platanaceae) 27. ROSALES (p. 291). 



Flowers not in monoecious heads. 



Plants with firm stems and leaves, not succulent. .25. RAN ALES (p. 243). 

 Plants with succulent stems and leaves. 



(Crassulaceae) 27. ROSALES (p. 291). 

 Carpels several and united. 

 Ovary inferior. 

 Stamens numerous. 



Hypanthium produced beyond the ovary. 



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

 Hypanthium not produced beyond the ovary. 



Ovary partly inferior (Hydrangeaceae) 27. ROSALES (p. 291). 



Ovary wholly inferior 35. OPUNTIALES (p. 431). 



Stamens not more than twice as many as the petals. 

 Styles wanting. (Stigmas sessile; aquatics.) 



(Gunneraceae) 37. MYRTALES (p. 459). 

 Styles present. 

 Styles distinct. 

 Ovules solitary in each cell; fruit a drupe or of 2 to 5 more or less united 



achenes 38. UMBELLALES (p. 474). 



Ovules several in each cell; fruit a capsule or a fleshy, many-seeded, 

 berry. 

 Fruit, if dehiscent, valvate. .(Families of) 27. ROSALES (p. 291). 

 Fruit circumscissile. 



(Portulacaceae) 24. CHENOPODIALES (p. 198). 

 Styles united or single. 



Plants with tendrils; fruit a pepo. 



(Cucurbitaceae) 48. CAMPANULALES (p. 612). 

 Plants without tendrils; fruit not a pepo. 

 Ovary exceeding the hypanthium, the top free. 



(Hydrangeaceae) 27. ROSALES (p 291). 

 Ovary inclosed in or surpassed by the hypanthium or adnate to it. 



Ovules solitary in each cell 38. UMBELLALES (p. 474). 



Ovules several in each cell. 

 Ovary with parietal placentae. 



(Loasaceae) 35. OPUNTIALES (p. 431). 

 Ovary with central or basal placenta;. 



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



