10 KEY TO THE GENERA OF MANHATTAN PLANTS. 



92. Dehiscence not explosive, valves erect 93 



93. Seeds exceedingly small and numerous, calyx supe- 



rior Qyrostachys 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 Macroculyx 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 <>r 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 Crucifkkae 35 



101. Calyx superior 102 



101. Calyx inferior 103 



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



102. Calyx 4-clef t, 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 



