KEY TO THE FAMILIES. 17 



97. Twining herbs; flowers in cymes, white; corolla 4-5 lobed. 149 Cuscutaceae 

 97. Herbs not twining; flowers in spikes, pale yellow; corolla 2- 



lipped. -------- 162 Orobranchaceae 



98. Corolla 2-lipped, — or corolla-lobes somewhat unequal, 99 



98. Corolla regular, 4-more lobed. --------- 102 



99. Stamens 2, ovary 1-celled, stigma 2-lipped, corolla 



spurred, ------- ISO Pinguiculaceae 



99. Stamens 4. didynamous; or 2, equal, - - 100 



99. Stamens 5, often 1-3 reduced to sterile filaments, or absent. - - 101 

 100. Ovary 2-celled, style terminal; stems enlarged at the jointed 



nodes, ___-__-- 159 Acanthaceae 



100. Ovary 4-celled, deeply 4-lobed. style central; stems 4-sided, - 157 Lamiaceae 

 100. Ovary 2 or 4-celled, style terminal; stems commonly 4-angled, 



156 Verbenaceae 

 101. Calyx 2-lipped or truncate, ----- 162 Bignoniaceae 



101. Calyx of 4-5 more or less united sepals; corolla imbricated 



in the bud, - - 158 Rhinanthaceae 



101. Calyx of 5 more or less united sepals; corolla convolute in the 



bud, ----____ 159 Acanthaceae 



102. Stamens fewer than corolla-lobes, ------- 103 



102. Stamens as many as corolla-lobes, - - 105 



103. Corolla 5-, rarely 4-lobed 99 



103. Corolla 4-, rarely 5-lobed, 104 



104. Shrubs or trees, ------ _ 141 Oleaceae 



104. Herbs, - -__ ____ 163 Plantaginaceae 



105. Perennial herbs or shrubby plants growing in and about 



swamps, -------- 150 Hydroleaceae 



105. No such swamp-plants, -------- 106 



106. Plants with stems prostrate or twining, leaves alternate; calyx, 

 corolla and stamens each 5; ovary 2-5 celled with 1-2 ovules 

 in each cavity; fruit a capsule, - 148 Convolvulaceae 



106. Plants with alternate leaves; calyx, corolla and stamens each 4-6, 



ovary 2-6 celled, --------- 107 



106. Plants with leaves chiefly basal; calyx and corolla each 4-lobed, 

 membranous; stamens 4 or 2; ovary 1-2- or 3-4-celled, flowers 

 in terminal spikes on scapes, - - - - 163 Plantaginaceae 



106. Plants different from the preceding ones, ------ 10s 



107. Ovules 1-2 in each cell; fruit a drupe; shrubs or trees, 105 Aquifoliaceae 

 107. Ovules numerous; fruit a berry or a capsule; herbs, vines or 



shrubs, -_---___ 152 Solanaceae 



108. Ovary 1-celled; calyx, corolla and stamens each 4-12; leaves oppo- 

 site, or alternate and scaly; fruit a capsule, - - 143 Gentianaceae 



108. Ovary - ; -celled, ----109 



108. Ovary 3-celled; calyx, corolla and stamens each 5; leaves alternate 



or opposite; fruit a capsule, ----- 151 Polemoniaceae 



108. Ovanes 2. nearly distinct, - - - - - - - - -112 



108. Ovanes 4. more or less cohering; calyx, corolla and stamens each 

 5; leaves alternate; fruit of 4 nutlets distinct or cohering, 



153 Borraginaceae 

 109. Ovary 2-celled; stamens 2 or 4; fruit a capsule, samara, berry 



or drupe, --------- 141 Oleaceae 



109. Ovary 2-celled; stamens 4-5, fruit a capsule, - - 142 Spigehaceae 



