18 KEY TO THE FAMILIES. 



109. Ovary 2-4 celled, fruit a drupe or of 2 or 4 nutlets, - - - 110 

 110. Stamens 2 or 4, - - - - - - - -156 Verbenaceae 



110. Stamens 5; styles or stigmas with a glandular ring; mainly herbs 



155 Heliotropaceae 



111. Styles united, stamens distinct, fruit of two follicles or a 



drupe, __---___ 145 Apocynaceae 



111. Styles only united above, stamens mostly united; flowers in 

 umbels with a crown between corolla and stamens adnate to 

 either or to both; fruit of 2 several-seeded follicles, 146 Asclepiadaceae 

 112. Succulent trailing or climbing herbs with alternate leaves; flowers 

 monoecious or dioecious; calyx and corolla each 5, stamens 

 mostly 3, ovary 1-3 celled, fruit a pepo, - 169 Cucurbitaceae 



112. Herbs, sometimes fleshy; stems erect or climbing; leaves opposite 

 and at the base whorled; flowers usually perfect; calyx lobed 

 or bristly; corolla 5-lobed; stamens 3; ovary 1-3 celled; fruit 

 an achene, -------- 167 Valerianaceae 



112. Green parasitic shrubs, flowers monoecious or dioecious; corolla and 



stamens each 2-6, ovary 1-celled, fruit a berry, - 164 Loranthaceae 

 112. Plants unlike the preceding ones, - - - - - - - 113 



113. Flowers not in involucrate heads, - - - - - - 114 



113. Flowers in involucrate heads (Compositae) , - - - - 118 



114. Stamens free from the corolla, or slightly adnate to the base, - 115 



114. Stamens more or less adnate to the corolla, - - - - - -117 



115. Herbs; stamens as many as the sepals, - - - - - 116 



115. Shrubs or small trees, stamens twice as many as the sepals, 



136 Vacciniaceae 

 116. Corolla 5-lobed, ovary 3-5 celled, ----- 170 Campanulaceae 



116. Corolla bilabiate or irregular, the tube split to the base on one side, 



ovary generally 2-celled, - 171 Lobeliaceae 



117. Herbs, shrubs or trees, with stipules adnate to the stems between 



the leaf-bases; corolla and stamens each 3-6, rarely 10, 165 Rubiaceae 

 117. Shrubs, vines or trees, without stipules, or with stipules adnate 

 to the petiole; corolla and stamens each 4-5; anthers versatile. 



166 Caprifoliaceae 

 118. Heads inconspicuous, with white or greenish disks; stamens 5, 



distinct, the anthers converging about the stigma, 172 Ambrosiaceae 

 118. Heads composed of only tubular florets, or the outer ones ligulate; 



stamens 5, the anthers united into a ring, - - 173 Carduaceae 

 118. Heads composed of only ligulate florets; stamens 5, the 



anthers connate around the style, - - - 174 Cichoriaceae 



