KEY FOR MARCH, APRIL AND MAY 



269 a Some stipules M> in. or more long, sharply toothed only 



at the base Lathyrus. p 174 



b Stipules usually less than Mi in. long or else toothed all 



around Vicia. p 174. 



270 a Leaves doubly compound ; flowers in racemes 



Capnoides. p 155 

 b Leaves 3-foliolate; flowers in heads. ... Trifolium. p 175 



271 a Plants 5 ft. or more long, twining Aristolochia. p 14.5 



b Plants less than 5 ft. long, not twining 272 



272 a Flowers without a spur; leaves clustered near the top 



of stem Poly gala paucifolia. p 179 



b Flowers with i petal spurred or sac-like 273 



273 a Lower petal sac-like; flowers about a /4 in. long 



Cubelium. p 188 

 b Lower petal spurred; flowers more than ^4 in. long 



Viola, p 187 



274 a Corolla with a spur at the base Linaria canadensis. p 210 



b Corolla not spurred at the base 275 



275 a All of stem leaves alternate 276 



b Some or all of stem leaves opposite or in whorls 278 



276 a Bracts subtending the flowers very conspicuous, scarlet 



Castilleja. p 212 

 b Bracts subtending the flowers not scarlet 277 



277 a Leaves pinnately lobed or divided Pedicularis. p 212 



b Leaves not pinnately lobed or divided. .. .Schwalbea. p 212 



278 a Leaves in a whorl near the summit of the stem 



Polygala paucifolia. p 179 

 b Leaves opposite, rarely in whorls 279 



279 a Calyx with a protuberance on the upper side 



Scutellaria. p 205 

 b Calyx not with a protuberance as in a 280 



280 a Flowers solitary or few together in the axils of the 



leaves, not in racemes 281 



b Flowers not arranged as in a 286 



281 a Flowers less than ^4 in. long, usually as broad as long 



Veronica. p2ii 

 b Flowers -V4 in. or more long, usually longer than broad 282 



282 a Plants creeping, with rounded or ovate-heart-shaped 



leaves 283 



b Plants erect or ascending ; leaves not rounded 284 



283 a Upper lip of corolla 2-lobed or notched; calyx about 



i5-nerved Glecoma. p 206 



b Upper lip of corolla entire; calyx 5-nerved. .Lamium. p 206 



284 a Calyx 4-toothed ; stamens 4 Melampyrum. p 212 



b Calyx 5-lobed or 5-parted; stamens 2 285 



20 



