KEY TO THE FAMILIES 



Fruit a capsule, dehiscent by apical or longitudinal 



valves. 44. ALSINACEAE 268 



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

 Stamens hypogynous, inserted under the gynoecium in the per- 

 fect flowers, not on a disk in the staminate flowers. 

 Flowers perfect. 

 Stamens not tetradynamous. 



Stamens 2; inflorescence spicate. 



(Besseya in) 117. SCROPHULARIACEAE 760 

 Stamens 3-10; inflorescence cymose or axillary. 

 Ovary 1-celled. 



Placentae parietal; pistils 2-carpillary. 



57. SAXIFRAGACEAE 376 



Placentae central or basal; pistils of 3-5 car- 

 pels. 



Calyx not petaloid, of 4 or 5 distinct sep- 

 als. 44. ALSINACEAE 268 

 Calyx more or less petaloid, campanulate, 

 merely 5-lobed. 



(Glaux in) 100. PRIMULACEAE 646 



Ovary 3-5-celled; leaves verticillate. 



41. TETRAGONIACEAE 261 

 Stamens tetradynamous. 



(Apetalous species in) 52. BRASSICACEAE 321 



Flowers monoecious or dioecious. 



74. EUPHORBIACEAE 541 



Stamens perigynous or epigynous, inserted on the margin of a 



hypanthium or a disk. 



Fruit a samara. 78. ACERACEAE 551 



Fruit drupe-like or berry-like. 



(Apetalous species in) 79. RHAMNACEAE 553 



b. Ovary inferior. 



Flowers not in involucrafee heads. 



Fruit a berry, or a drupe, or nut-like. 



Shrubs, with scurfy and usually silvery leaves. 



89. ELAEAGNACEAE 581 

 Herbs, not with scurfy leaves. 



Stamens as many as the perianth-members and alternate 



with them, or fewer. 41. TETRAGONIACEAE. 261 



Stamens as many as the perianth-members and opposite 



them, or twice as many; water plants. 

 Water plants, with whorled leaves. 



92. HALORAGIDACEAE 605 

 Land plants, parasitic or saprophytic, with alternate 



leaves. 126. SANTALACEAE 817 



Fruit a capsule. 



Sepals as many as the ovary-cavities, or one-half as many. 

 Hypanthium merely enclosing the ovary. 



90. LYTHRACEAE 582 

 Hypanthium adnate to the ovary. 91. ONAGRACEAE 583 



Sepals not of the same number as the ovary-cavities. 



Styles 2; leaves alternate. 57. SAXIFRAGACEAE 376 



Styles 6; leaves 2, basal. 128. ARISTOLCCHIACEAE 821 



Flowers, at least the staminate, in involucrate heads. 



Calyx corolla-like. 40. NYCTAGINACEAE 255 



Calyx not corolla-like. 133. AMBROSIACEAE 827 



Corolla present. 

 I. Petals distinct, at least at the base. 



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

 Stamens at the base of the receptacle, i. e., hypogynous. 



Plants with relatively firm stems and leaves, not succulent. 

 Stamens numerous; anther-sacs opening by slits. 



Submerged water plants with minute axillary sessile monoe- 

 cious flowers; anthers with horn-like appendages. 



46. CERATOPHYLLACEAE 284 



Land plants or rarely water plants with perfect or rarely 

 dioecious flowers; anthers not with horn-like appendages. 



48. RANTTNCULACEAE 285 

 Stamens definite (in ours 6) ; anther-sacs opening by hinged-valves. 



49. BERBERIDACEAE 315 

 Plants with succulent stems and leaves. 55. CRASSULACEAE 373 



Stamens on the margin of a hypanthium (the hypanthium very small 



in some Saxifragaceae) . 

 Flowers regular or nearly so (actinomorphic) . 



Endorsperm present, usually copious and fleshy. 

 Herbs; stipules mostly wanting. 



Carpels as many as the sepals; succulent plants. 



55. CRASSULACEAE 373 



