10 KEY TO THE FAMILIES 



Stamens tetradynamous. 



(Apetalous species in) 52. Brassicaceae 90 



Flowers monoecious or dioecious. 



74. EUPHORBI.\CE.\E 150 



Stamens perigynous or epigynous, inserted on the naargin of a 

 hypantliium or a dislc. 

 Fruit a samara. 78. ACERACE.VE 153 



Fruit drupe-like or berry-like. 



(Apetalous species in) 79. Rhamnace.ae 153 



b. Ovary inferior. 



Flowers not in involucrabe heads. 



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



Shi'ubs, with scurfy and usually silvery leaves. 



89. El.\eagnace.ae 100 

 Herbs, not with scurfy leaves. 



Stamens as many as the perianth-members and alternate 



with them, or fewer. 41. Tetragoniaceae. 80 



Stamens as many as the perianth-members and opposite 

 them, or twice as many; water plants. 

 Water plants, with whorled leaves. 



92. Haloragidace.ae 166 



Land plants, parasitic or saprophytic, with alternate 



leaves. 126. Saxtalace.\e 221 



Fruit a capsule. 



Sepals as many as the ovarj'-cavities. 



Hypanthium merelj' enclosing the ovary. 



90. Lythraceae 160 

 Hypanthium adnate to the ovary. 91. Onagraceae 160 



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



Styles 2; leaves alternate. 57. Saxifragaceae 110 



St.vles 6; leaves 2, basal. 128. Aristolcchiace.ae 222 



Flowers, at least the staniinate, in involucrate heads. 



Caly.x corolla-like. 40. Nyctaginaceae 78 



Calyx not corolla-like. 133. AMBROSIACEAE 223 



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., hypogjmous. 



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 86 

 Land plants or rarely water plants with perfect or rarely 

 dioecious flowers; anthers not with horn-like appendages. 



48. Raxuncul.\ce.\e 86 

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



49. Berberid.\ceae 94 

 Plants with succulent stems and leaves. 55. Crassulaceae 110 



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 110 



Carpels fewer than the sepals, 2 or rarely 3, distinct or 

 only partly united; plant scarcely succulent. 



57. S.VXIFRAGArEAE UO 



Shrubs or trees; fruit thin- walled follicles; stipules present. 



(Upulaster in) 60. Kos.\CEAE IKl 



Endosperm wanting or scant; stipules mostly present. 



Carpels several or numerous, or, if soUtar v, becoming an achene. 



60. Ros.\CEAE 116 



Carpel soUtary. not becoming an achene. 



Ovary 2-ovuled; fruit a drupe; leaves simple. 



62. AMY'GDAL.^CEAE 12S 



Ovary several-ovuled ; fruit a legume; leaves pinnately 



compomid. 63. jNIimosaceae 129 



Flowers irregular (mostly zygomorpliic). 



Upper petal enclosed by the lateral ones in the bud; corolla not 



papflionaceous. 64. Caesalpiniaceae 129 



Upper petal enclosing the lateral ones in bud; corolla papilionace- 

 ous. 65. Fab.\ceae 129 



2. Carpels several and united. 



a. Ovary superior. 



* Stamens inserted at the base of the ovary or receptacle. 

 t Stamens numerous. 



