4 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. 



(Bessey a in) 117. Scrophulariaceak 760 

 Stamens 3-10; inflorescence cymose or axillary. 

 Ovary 1-ceUed. 



Placentae parietal ; pistUs 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. Primulace.\E 646 

 Ovary 3-5-celled; leaves verticiUate. 



41. Tetragonlaceae 261 



Stamens tetradynamous. 



(Apetalous species in) 52. Brassicaceae 321 



Flowers monoecious or dioecious. 



74. Euphorbiace.ae 541 



Stamens perigynous or epigjTious, 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 involucrabe 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. Ltthraceae 582 

 Hypanthiumadnate to the ovary. 91. Onagraceae 583 



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



Styles 2; leaves alternate. 57. S.axifragaceae 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-hke. 133. Ambrosiaceae 827 



B. 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. RANU.VCULACEAE 285 

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



49. Beuberidaceae 315 

 Plants with succulent stems and leaves. 5."). Ckassulace.\e 373 



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

 in some Saxifragaceae). 

 Flowers regular or nearly so (actlnomorphlc). 



Endorsperm present, usually copious and fleshy. 

 Herbs; stipules mostly wanting. 



Carpels as many as the sepals; succulent plants. 



55. Crassulaceae 373 



