xii GENERAL KEY TO THE ORDERS AND FAMILIES. 



Petals present; leaves deciduous, except in Cyrillaceae and some Ilicaceae. 



Low annual herbs, with pinnately divided leaves, the stamens twice as many as the petals. 



Fam. 61. Limnanthaccae. 2: 385. 

 Trees or shrubs, or rarely herbaceous vines. 



Ovary i-celled (in ours); fruit a small drupe. Fam. 62. Anacardiaceae. 2: 385. 



Ovary 2-several-celled. 



Leaves simple, pinnately veined. 

 Seeds not arilled. 



Fruit dry; flowers racemed, perfect. Fam. 63. Cyrillaceae. 2: 3*9. 



Fruit a small drupe; flowers not racemed, mostly polygamo-dioecious; ovules 



pendulous. Fam. 64. Ilicaceae. 2: 390. 



Seeds aiilled; ovules erect; capsule fleshy. Fam. 65. Celastraceae. 2:393. 



Leaves simple and palmately veined, or compound. 



Leaves opposite. 



Fruit a bladdery 3-lobed capsule. Fam. 66. Staphyleaceae. 2: 396. 



Fruit of 2 winged samaras. Fam. 67. Aceraceae. 2:396. 



Fruit a leathery capsule; flowers irregular; leaves digitately compound. 



Fain. 68 Hippocastanaceac. 2: 400. 

 Leaves alternate; fruit various. Fam. 69. Sapindaceae. 2:402. 



b. Flowers very irregular, the posterior sepal large, saccate; succulent herbs, the capsule 



elastically dehiscent. Fam. 70. Balsaminaccae. 2: 403. 



t t Stamens as many as the sepals and alternate with them, opposite the petals when 



these are present; ovules erect. Order 18. Rhamxales. 



Shrubs, small trees, or vines; petals 4 or 5, or none; fruit a drupe or capsule. 



Fam. 71. Rhamnaceae. 2: 404. 

 Vines, climbing by tendrils, rarely shrubs; petals caducous; fruit a berry. 



Fam. 72. Vilaceae. 2: 407. 

 rf vr Stamens usually very numerous ( except in some Hypericaceae, in Elatinaceae, Violaceae 



and Passifloraceaej; disk inconspicuous or none, 

 t Sepals valvate; placentae united in the axis of the capsule. Order 19. Malvales. 

 Stamens in several sets; anthers 2-celled; embryo straight. Fam. 73. Tiliaceae. 2:413. 



Stamens monadelphous; anthers i-celled; embryo curved. Fam. 74. Malvaceae. 2: 415. 



t t Sepals or calyx-segments imbricated or convolute (except in Loasaceae, in which the calyx-tube 

 is adnate to the ovary); placentae mainly parietal, sometimes united in the axis. 



Order 20. Parietales. 

 Sepals distinct, mostly persistent. 

 Endosperm little or none. 



Trees or shrubs with alternate leaves, and large solitary axillary flowers. 



Fam. 75. Theaceae. 2: 426, 

 Herbs or low shrubs with opposite, rarely verticillate leaves. 



Leaves punctate or black-dotted, exstipulate. Fam. 76. Hvpericaceae. 2: 427 



Leaves stipulate; minute or small marsh or aquatic herbs with axillary flowers. 



Fam. 77. Elatinaceae. 2: 437 

 Endosperm copious. 



Flowers regular, but the 2 outer sepals smaller; stamens numerous; ovules orthotropous. 



Fam. 78. Cistaceae. 2: 439 

 Flowers irregular, some often cleistogamous; stamens 5; ovules anatropous. 



Fam. 79. Violaceae. 2: 445 

 Sepals more or less united into a gamosepalous calyx. 



A fringed crown in the throat of the calyx; our species vines; stamens 5; ovary free from 



the calyx. Fam. 80. Passtfloraceae. 2: 457 



No crown; our species herbs; stamens numerous; ovary adnate to the calyx. 



Fam. 81. Loasaceae. 2: 458, 

 II. Ovary inferior, adnate to the calyx, wholly, or in part (except in Lythraceae and our Melasto- 

 maceae, where it is usually merely enclosed by it, and in Thymeleaceae and Elaeagnaceae, 



which are shrubs or trees, with no corolla). 



1. Fleshy spiny plants, with jointed stems, the leaves very small, or none; calyx-segments and 



petals very numerous. Order 21. Opuxtiales. 



One family. Fam. 82. Cactaceae. 2: 460. 



2. Herbs, shrubs or trees, not fleshy nor spiny; calyx-segments and petals (when present) rarely 



more than 5. 

 Petals none in our species; shrubs or trees; ovary i-ovuled. Order 22. Thymeleales. 



Leaves green; seed pendulous. Fam. 83. Thymeleaceae. 2:465. 



Leaves silver-scurfy; seed erect. Fam. 84. Elaeagnaceae. 2:466. 



Petals present (except in some Haloragidaceae, which are small aquatic herbs). 



Ovules several or numerous in each cavity of the ovary (except in Haloragidaceae and Trap- 

 aceae). Order 23. Myrtales {Myrtiflorae). 



Land or marsh plants, or, if aquatic, submerged leaves not dissected. 



Calyx-tube merely enclosing the ovary, but free from it, except at the base. ) 



Anthers longitudinally dehiscent. Fam. 85. Lythraceae. 2: 468. 



Anthers opening by a terminal pore. Fam. 86. Melastomaceae. 2: 473. 



Calyx-tube almost wholly adnate to the ovary. Fam. 87. Onagraceae. 2: 475. 



Aquatic or amphibious herbs, the submerged leaves dissected (except in Hippuris, which 



has whorled narrow r leaves and only 1 stamen). 



Petioles of the broad floating leaves inflated; flowers rather large, white. 



Fam. 88. Trapaceae. 2: 500. 



Leaves most sessile; petioles, if present, not inflated; flowers small, greenish; seeds 



with 1 coat. Fam. S9. Haloragidaceae. 2: 500. 



Ovules 1 in each cavity of the ovary. Order 24. Umbellales ( Umbellifiorae). 



Stamens 5; styles 2-5, rarely united; flowers umbellate or capitate. 



Fruit a fleshy berry or drupe. Fam. 90. Araliaceae. 2: 505. 



Fruit dry when mature, splitting into two mericarps. Fam. 91. Umbelliferae. 2: 508. 

 Stamens 4; style 1; stigma 1; shrubs and trees; flowers not umbellate. 



Fam. 92. Cornaceae. 2: 542. 



