KEY FOR MARCH, APRIL AND MAY 



235 a Ovary inferior 236 



b Ovary superior 239 



236 a Petals 4; flowers 1-2 in. broad Kneijfia. p 190 



b Petals usually 5; flowers about ^4 in. or less broad 237 



237 a Leaves simple, linear, arranged in whorls. Galium verum. p 214. 

 b Leaves not completely as in a 238 



238 a Fruit or ovary conspicuously winged, not flattened 



Thaspium. p 193 



b Fruit not winged, somewhat flattened Zizia. p 193 



239 a When broken plant exudes a yellow juice. Chelidonium. p 155 

 b Plants not as in a 240 



240 a Stamens 15 or more 241 



b Stamens 10 or less 248 



241 a Perianth not differentiated into a green calyx and 



colored corolla Caltha. p 152 



b Perianth differentiated into green calyx and colored 



corolla 242 



242 a Pistils 1-6 243 



b Pistils 10 or more 244 



243 a Leaves compound, chiefly basal W ' aldsteinia. p 165 



b Leaves simple Helianthemum. p 186 



244 a Calyx with distinct sepals which readily pull off 



Ranunculus, p 153 

 b Calyx more or less united at the base, the lobes not 



readily pulled off 245 



245 a Leaves pinnately divided ; flowers V in. or less broad 



Geum vernum. p 165 

 b Leaves palmately divided 246 



246 a Plants erect Potentilla. p 165 



b Plants prostrate or ascending 247 



247 a Leaflets 3 Duchesnea. p 165 



b Leaflets usually 5 or more, or a few leaves with 3 



Potentilla. p 165 



248 a Leaves compound with 3 inversely heart-shaped leaflets 



Oxalis. p 178 

 b Leaves not as in a 249 



249 a Leaves opposite Naumbergia. p 198 



b Leaves alternate 250 



250 a Style thread-like, much exserted Onosmodium. p 203 



b Style not thread-like or exserted Lithospermum. P 203 



Terrestrial Green Herbs With Flowers Neither 

 Green nor Yellow 



251 a Several small flowers collected into a dense head which 



is subtended by an involucre of bracts, as in the Daisy, 



not as in the Clover 252 



b Flowers not arranged completely as in a 261 



It 



