272 The Botanical Gazette. [September, 
LUDWIGIA POLYCARPA S, & P.—The flowers are wholly 
devoid of entomophilous characters. The petals are wanting, 
and there is no nectar. The four stamens bend inwards, 
bringing the anthers in contact with the stigma. Spontane- 
ous self-pollination is therefore a regular occurrence. 
CENOTHERA BIENNIS L.*—The following list was observed 
on Aug. 26th and 2oth: 
Apide: (1) Bombus americanorum F. ¢ %, s. and. Ps 
freq. ; (2) Melissodes bimaculata Lep. 9, c. p.; (3) M. obliqua 
ay Gc) <p: 
Trochilide: (4) Trochilus colubris L., s., two. 
I have found the flowers in bloom from July 22nd to Oct. 
15th. 
Miller found it visited by one Macroglossa, three Bombus, 
one Apis, one Colletes, one Panurgus, three Eristalis. 
effect self-pollination. When two or more flowers are & 
panded at the same time cross-pollination betwee 
the same plant may occur. In the usual case 1 : 
stem exposes only one open flower at a time cross-pollinat 
between distinct plants is the rule. 
The tube measures 14-20 mm., so 
drained by the largest bees, but shorter-tongued 
sometimes able to reach a little of the nectar which 
the tube. for 
Besides the long-tongued insects which visit the flower ; 
nectar i i Andrenidae ¢ 
Accordingly 
jon 
that it can only be 
bees # 
rises 12 
between May 28th and June igth, the following list w@ 
served: 
ERE Hee tate ome eee 
*See Miller: Fertilization of F lowers, 246. 
