Robertson — Flowers and Insects — Labiate. 123 
canorum F. 8; (3) Ceratina dupla Say 9; (4) Megachile brevis Say 9, 
on 
e. 
Diptera — Bombylide: (5) Bombylius atriceps Lw. 
Lepidoptera — Rhopalocera: (6) Pieris protodice B.-L., freq. —all s. 
Leonurus Cardiaca L. —‘‘ Nat. from Eu.’’ — This plant 
is common, growing along side-walks and road-sides. The 
stems rise 5 to 10dm. and with the nearly erect branches, 
bear many whorls of flowers which appear as if arranged in 
a long leafy spike. Only a few flowers are open at a time in 
each whorl. 
The corolla is whitish, the upper lip being pale purplish 
beneath and the lower being marked with brownish and purple. 
The lips are strongly divergent. The lower has the middle 
lobe folded and the lateral strongly reflexed. The upper lip 
is oblong and somewhat galeate, protecting the dehiscent 
anthers. Later, when the stigma becomes receptive, the 
upper lip is reflexed. 
The flower is properly fertilized by bees in search of honey, 
and the pollen is applied to their backs. But small bees, like 
Halictus, collect the pollen, hanging to the strongly bearded 
upper lip while doing so. They no doubt neglect the flowers 
in the second stage, although they may sometimes effect polli- 
nation by alighting upon the style and stamens after the galea 
becomes reflexed. The flowers bloom from June 8 to Oct. 
18. June 15 and 22 the following list of visitors was 
observed ; — 
Hymenoptera — Apide: (1) Apis mellifica L. 8, s., ab.; (2) Anthophora 
abrupta Say 6‘, s.; (3) Ceratina dupla Say 9, s. and c. p., freq.; Andrenide: 
(4) Halictus tering 2, ¢. p.; (6) H. confusus Sm. 9, c. p., ab.; (6) 
H. stultus Cr. 
Diptera — ironies : (7) Syrphus ribesii L.; (8) Mesograpta geminata 
Say; (9) Allograpta dblitas Say — all feeding on stray pollen. 
t Wood’s Holl, Mass., in July, Professor Trelease saw the flowers 
visited by (1) Apis mellifica L. 8 ; (10) Bombus virginicus Oliv, 8 ; (11) B. 
americanorum F. 8 ; (12) Pieris rape L. 
In Europe, where the plant is indigenous, Miiller found it 
visited by Apis and four species of Bombus.* 
* Weit. Beobachtungen and Alpenblumen. 
