8 KEY TO THE FAMILIES 



Ovule with a ventral raphe; leaves mostly alter- 

 nate; blades lobed or compound. 



94, ARAUACEAE 633 



Ovule with a dorsal raphe; leaves mostly op- 

 posite; blades entire or merely toothed. 



95. CORNACEAE 634 



Fruit dry. a cremocarp; gynoecium 2-carpellary ; 



stigmas terminal. 93. Ammiaceae 606 



Styles united, or single. 



Ovary enclosed in or surpassed by the hypanthium or 



adnate to it. 

 Anthers opening by pores; fruit a berry. 



99. Vaccintaceae 643 



Anthers opening by slits; fruit a capsule. 

 Ovary with parietal placentae. 



87. LOASACEAE 569 



Ovary with central or basal placentae. 



Hypanthium merely enclosing the ovary. 



90. Lythraceae 582 

 Hypanthium adnate to the ovary. 



91. Onagraceae 583 



Ovary exceeding the hypanthium, the top free. 



58. HYDRANGIACEAE 392 



Plants with tendrils ; fruit a pepo; leaf-blades palmately veined. 



„ ^ ^ , , 129. CUCURBITACEAE 821 



II. Petals more or less united. 



A. Ovary superior. 



1, Stanaens free from the corolla. 



Gynoecium of a single carpel; corolla papiUonaceous. 



^ 65. Fabaceae 454 



Gj-noecium of several imited carpels. 



Filaments imited. 



Stamens diadelphous. 51. Fumariaceae 319 



Stamens monadelphous. 



Anther-sacs opening by slits; calyx and corolla regular. 



. , 67. Oxalidaceae 533 



Anther-sacs openmg by pores; calyx and corolla very 



irregular. 73. Polygalaceae 540 



Filaments distinct. 



Corolla regular; anthers distinct. 



Herbaceoiis saproph^-tes, without green leaves. 



„ , 97. Monotropaceae 638 



Herbs or shrubs with green leaves. 



Corolla of essentially distinct petals, f. e., united only 

 at the base; herbs with rootstocks. 



96. Pyrolace.\E 635 



Corolla of distinctly united petals ; shrubs. 



^ 98. Ericaceae 639 



Corolla irregular; one of the petals free; anthers united. 



69. Balsaminaceae 536 



2. Stamens partially adnate to the corolla. 



a. Staznens as many as the lobes of the corolla and opposite them, or 



twice as many or more; ovary 1-celled; placentae central or 

 basal. 100. Primul.\ceae 646 



b. Stamens as many as the lobes of the corolla and alternate with 



them, or fewer, 



* Corolla not scarious, veiny; fruit various, but not a pyxis, 

 t Carpels distinct, except sometimes at the apex. 



Styles united; stamens distinct or gjTiandrous. 



„ , ,. . 105. Apocynaceae 667 



Styles distinct; stamens monadelphous. 



106. ASCLEPIADACEAE 669 



tt Carpels united. 



Ovary 1-celled. with central placentae. 



Corolla-lobes convolute or imbricated in the bud; leaves 

 typically opposite and simple. 



^ „ , , 103. Gentian ace AE 657 



Corolla-lobes mduplicate-valvate in the bud; leaves al- 

 ternate, in ours mostly basal and trlfoUolate. 



^ 104. MEXYANTHACEAE 667 



Ovary 2-3-celled, or falsely 4-celled, or if 1-cclled with 



parietal placentae. 

 Stamens 2, opposite to each other; corolla regular. 



101. Ol^ACEAE 655 



Stamens usually more than 2, if only 2 not opposite to 



each other and the corolla irregular. 

 Leaves with stipules or stipular lines. 



102. LOGANIACEAE 657 



