WILD FLOWERS OF M.W YORK 1*9 



Common Evening Primrose 

 Oenothera biennis Linnaeus 



Plate 145a 



Stems stout, wandlike and simple or somewhat branched, 1 to 6 feet 

 high from a biennial root. Stems and leaves somewhat hairy. Leaves 

 lanceolate to ovate-lanceolate, sessile, 2 to 6 inches long, the lower ones 

 with petioles, the upper ones much reduced in size; margins with low, 

 distant teeth. Flowers in the axils of the reduced upper leaves (or bracts), 

 bright yellow, 1 to 2 inches broad in terminal spikes, opening in the evening; 

 calyx tube slender, two or three times longer than the ovary, its four slender 

 lobes reflexed; petals four, broadly obovate; stamens eight, equal in length, 

 the linear anthers on threadlike filaments. Fruiting capsules oblong, nar- 

 rowed toward the apex, three-fourths to 1 \ inches long and longer than the 

 upper leaves (or bracts), one-eighth to one-fourth of an inch thick. 



Dry or sandy soil in fields, waste ground and along roadsides, Labrador 

 to Minnesota, south to Florida and Texas. Flowering from the latter 

 part of June until autumn. Often appearing like a weed. 



The Evening Primrose is a variable species and consists of several 

 races or mutants which have been regarded as valid species. There are 

 also two other closely related species in addition to the next one which is 

 described. They are the Small-flowered Evening Primrose (Oenothera 

 c r u c i a t a Nuttall) , with linear-lanceolate calyx segments and linear 

 petals, one-fourth to one-half of an inch long, found usually in sandy soil 

 from Maine and Massachusetts to northern New York; and Oakes's Evening 

 Primrose (Oenothera oakesiana Robbins), a dull-green plant 

 covered with a soft, appressed pubescence, rather large flowers with linear- 

 lanceolate calyx segments and obovate petals one-half to three-fourths of 

 an inch long. Frequent in sandy soil in southern New England, Long 

 Island and Eastern New York. 



