OCTANDRIA, MONOGYNIA. 181 
185. CENOTHERA. Gen. pi. 637. (Ona^'ra.) 
Caliw tubulous ; 4-cleft, segments deflected, 
deciduous. Petals 4, inserted upon the ca- 
lix. Stigma 4-cleft. Capsule 4-celled, 4- 
valved, inferior. Seeds naked, affixed to a 
central 4-sided receptacle. — JSTutt. 
1. (E. stem villous, scabrous, leaves ovate-lanceo- biennis, 
late, flat •, flowers terminal, subspicate-sessile, 
with the stamens shorter than the corolla.-— 
Wind. 
CEnothera mollissima, Walt. ? 
Icon. FI. Dan. 446, 
Evening Tree-primrose. 
This elegant ornament of our field-hedges, is cultivated 
sometimes in our gardens, where its flowers acquire a much 
finer yellow colour, and becomes larger. They are generally 
of a pale yellow, and open in the evening, just as the sun 
leaves the horizon. This opening is effected by a very sud- 
den retraction of the calix leaves, which are forcibly thrown 
against the peduncles, and an immediate expansion of the pe- 
tals. The flowers continue thus expanded till the sun is about 
an hour or two high, when they are partially closed, and again 
open at evening. The flowers are very numerous, and I am 
not certain that the same one opens a second time ; perhaps 
not, I have cultivated the plant in my garden, and in that 
state the same flower was but once expanded, andthenfaded. 
Mr. Pursh has noticed an appearance of phosphoric light ema- 
nating from the flowers of this evening primrose, during very 
dark nights. The plant is about three or four feet high. On 
the borders of cultivated fields, and in natural hedges, very 
common. Also, occasionally, in thickets, along watercourses. 
In the latter situation the leaves often become diseased, when 
they assume a whitish appearance. Biennial. August 
2. ®. smoothish, leaves lanceolate, subdentate, fratiess®, 
acute; capsules pedicellate, oblong-clavate, an- 
gled.— IFiZW. 
Icon. Bot. Mag. 332. 
17 
