10 KEY TO THE GENERA OF MANHATTAN PLANTS. 



92. Dehiscence not explosive, valves erect 93 



93. Seeds exceedingly small and numerous, calyx supe- 



rior Gyrostachys 28 



93. Seeds rather few, sepals 5, inferior 94 



94. Sepals about equal, leaves all opposite Hypericum 152 



94. Sepals unequal, 2 much smaller, leaves mostly 



alternate Helianthemum 153 



95. Seeds 4, calyx enlarged, 5 lobed Macrocalyx 194 



95. Seeds more than 4 96 



96. Seeds borne all over the inside of the valves. . .' Gentiana 187 



96. Seeds borne only along the suture 97 



97. Seeds crested, oblong Bicuculla 70 and Capnoides 71 



97. Seeds not crested, kidney-shaped Capparidaceae 36 



98. Capsule 2-valved, smooth herb Orobanche 232 



98. Capsule 4 or 5 valved, prickly herb ■. Argemone 69 



99. Placentae parietal 100 



99. Placentae axile 101 



100. Placenta 1, fruit 1 carpelled Astragalus 114 



100. Placentae 2, connected by a false partition Cruciferae 35 



101. Calyx superior 102 



101. Calyx inferior 103 



102. Calyx 5 cleft, 10-angled, seeds numerous Lobelia 244 



102. Calyx 4-cleft, 4-ribbed, seeds few Houstonia 236 



103. Seeds few (1 to 8) 104 



103. Seeds numerous 105 



104. Seeds 2, crested Polygala 127 



104. Seeds 4 to 8, lenticular, supported by curved stalks 



ACANTHACEAE 86 



104. Seeds 2 to 6, angular, no long stalks Convolvulaceae 747 



105. Capsule thorny, imperfectly 4-celled Datura 221 



105. Capsule membranous, enclosed in the 10-14 ribbed 



calyx tube Lythrum 162 



105. Not as above, calyx usually persistent, inferior 



SCROPHULARIACEAE 83 



