EVENING OR TREE PRIMROSE. 1S7 



between six and seven o'clock, which is thus no- 

 ticed by Dr. Langhome : 



*' Thou vainer flowers, tlio' sweeter far, 

 The Evenin^^ Primrose shuns tlic day ; 

 Blossoms only to the western star, 

 And loves its solitary ray." 



We have frequently stood over this plant to 

 watch the expansion of its flowers, the petals of 

 which are confined together by means of the 

 calyx, the ends of which meet over the corolla, 

 and clasp each other by a hook. As the corolla 

 swells in its confinement the segments of the 

 calyx separate at bottom, and discover the prim- 

 rose corolla, which appears to be gradually in- 

 flating with a gaseous fluid until it acquires suf- 

 ficient expansive force to burst the hooks of the 

 calyx. When its petals are thus freed they ex- 

 pand instantaneously to a cup shape, and in 

 about half an hour after they progressively spread 

 until they become quite flat ; by the morning the 

 flowers become flaccid, so that the impregnation 

 must take place after sunset. 



The Great-flowered Evening Primrose, (Eno- 

 thera GrandiJIora, is also a native of North Ame- 

 rica, and was introduced to our gardens in the 

 year 1778, by John FothergiU, M.D. This spe- 

 cies possesses an agreeable fragrance, and hence 

 it is more esteemed than the Biewds. 



