10 KEY TO THE FAMILIES 



stamens tetradynaraous. 



(Apetalous species in) 52. Bbassicaceae 9fi 



Flowers monoecious or dioecious. 



74. EUPHORBI.YCBAE 150 



stamens perigynous or epigynous, inserted on the margin of a 

 liypanthium or a disk. 

 Fruit a samara. 78. ACERACEAE 153 



Fruit drupe-like or berry-like. 



(Apetalous species in) 79. Rhamnacbae 153 



b. Ovary inferior. 



Flowers not in involucrate heads. 



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



Shrubs, with scurfy and usually silvery leaves. 



89. El.aeagnaceae IfiO 

 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. Haloragidaceae 166 



Land plants, parasitic or saprophytic, with alternate 



leaves. 126. Santalaceae 221 



Fruit a capsule. 



Sepals as many as the ovary-cavities. 



Hypanthium merely enclosing the ovary. 



90. LYTHRACE.AE 160 



Hypanthiumadnateto the ovary. 91. Oxagpsaceae 160 



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



Styles 2: leaves alternate. 57. Saxifragaceae 110 



Styles 6; leaves 2, basal. 128. Aristolcchiacbae 222 



Flowers, at least the staminate, in involucrate heads. 



Calv-x corolla-like. 40. Nyctagixaceae 78 



Calyx not coroUa-like. 133. Ambkoslaceae 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., 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-Uke appendages. 



46. Ceratophyllaceae 86 

 Land plants or rarely water plants with perfect or rarely 

 dioecious flowers; anthers not with horn-like appendages. 



48. RANUNCnLACEAE 86 



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



49. Berberidaceae 94 

 Plants with succulent stems and leaves. 55. Crassulace.ae 110 



Stamens on the margin of a hypanthiinn (the hypantiiium 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. CRASSCL.ACEAE 110 



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

 only partly united; plant scarcely succulent. 



57. S-OCIFRAGACEAE 110 



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



{Opulaster in) 60. ROS.ACEAE 116 



Endosperm wanting or scant; stipules mostly present. 



Carpels several or numerous, or, if soUtary , becoming an achene. 



60. KOSACEAE 116 



Carpel soUtary. not becoming an achene. 



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



62. A.MYGDALACEAE 128 



Ovary several-ovuled ; fruit a legume; leaves pinnately 



compound. 63. Mimosaceae 129 



Flowers irregular (mostly zygomorphlc) . 



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



papilionaceous. 64. Caesalpiniaceae 129 



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

 ous. 65. Fabaceae 129 



2. Carpels several and united. 



a. Ovary superior. 



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

 t Stamens numerous. 



