14 KEY TO THE FAMILIES 



Stamens diadelphous. 51. Fumariaceae 95 



Stamens monadelphous. 



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



67. OX.\LIDACEAE 149 



Anther-sacs opening by pores; caly.v and corolla very 



irregular. 73. Polygalaceae 150 



Filaments distinct. 



Corolla regular: anthers distinct. 



Herbaceous saprophytes, without green leaves. 



97. jNIoxotropaceae 174 



Herbs or shrubs with green leaves. 



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

 at the base; herbs with rootstocks. 



96. Pyrolaceae 174 



Corolla of distinctly united petals; shrubs. 



9.8. Ericaceae 174 



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



69. Balsamin.vceae 149 



2. Stamens partially adnate to the corolla. 



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



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

 basal. 100. Pkimulaceae 176 



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 gynandrous. 



105. Apocyxaceae 181 



styles distinct; stamens monadelphous. 



100. ASCLEPIADACEAE 183 



tt Carpels united. 



Ovary 1-celled, with central placentae. 



Corolla-lobes convolute or imbricated in the bud ; leaves 

 typically opposite and simple. 



103. Genti.\n.\ceae 179 

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

 ternate, in ours mostly basal and trifoliolate. 



104. IMexyanthaceae 181 

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



parietal placentae. 

 Stamens 2, opposite to each other; corolla regular. 



101. Ole.\ceae 179 

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



each other and tlie corolla irregular. 

 Leaves with stipules or stipular lines. 



102. Loganiaceae 179 

 Leaves without traces of stipules. 



Stamens 5, if only 3-4, not didynamous. 



Fruit a capsule or berry; ovary not 4-lobed. 

 Styles or stigmas usually distinct. 



' Parasitic twining plants, with scale- 

 like leaves. 



108. Cuscutaceae ■ 184 

 Plants not parasitic; leaves normal. 



Inflorescence not scorpioid; flowers 

 cyraose or solitary ; ovar j- 2-3 

 celled. 



Corolla plaited and the plaits 

 convolute in the bud; flow- 

 ers axillary, solitary or 

 cymose-conglomerate; plants 

 usually twining. 



107. Coxvolvulaceae 183 



Corolla merely convolute in the 

 bud, not plaited; flowers 

 cymose; plants never twin- 

 ing. 



109. Polemoniaceae 184 

 Inflorescence more or less dis- 

 tinctly scorpioid; ovary in 

 ours 1-celled or imperfectly 

 2-celled. 



Fruit a capsule. 



110. HYDROPnYLL.\CEAE 190 



Fruit more or less drupaceous. 



111. Ehretiaceae 193 

 Styles and stigmas wholly united. 



Ovules few. 109. Coxvolvulaceae 183 

 Ovules numerous. 



