124 Trans. Acad. Sci. of St. Louis. 
Stachys palustris * L.—‘‘ Wet ground, Newfoundland to 
the Pacific in Oregon, south to Penn., and in the Rocky 
Mountain region to N. Mexico, north to Mackenzie River 
(Eu., N. Asia)’?— The stem grows from2 to 10 dm. high. 
The flowers are arranged in whorls of six or more in the axils 
of the upper leaves, the uppermost whorls being approximated 
in loose spikes. Spikes of this kind terminate the stem and 
several branches, so that the flowers are rendered quite con- 
spicuous and attractive to insects. 
The corolla is pale purplish, measuring about 11 mm. long. 
The upper lip forms a well-developed helm, which serves as 
an efficient protection for the anthers. The helm is 4 mm. 
long and 3 mm. wide. The lower lip affords a convenient 
horizontal landing place about 6 mm. in extent, with large 
lateral lobes and a larger rounded middle one. 
he flowers are proterandrous. In the first stage the flow- 
ers are less expanded, so that the visiting insects are more 
likely to touch the anthers. In the second stage the flower is 
more widely expanded, but then the receptive stigma is ex- 
serted considerably beyond the helm and is held down towards 
the lower lip in such a position that it is apt to touch a bee as 
it alights. From the mode of development of the flowers, 
visiting insects are most likely to approach the lower flowers 
first, proceeding upwards to those discharging pollen, which 
they carry in turn to the lower receptive flowers of the next 
spike. 
Pollination may occur between different flowers of the same 
plant on different spikes. Cross-pollination occurs between 
distinct plants when the bee changes plants. I have not been 
able to satisfy myself that spontaneous self-pollination takes 
place, though Miiller states that it does. 
The flower shows the normal melittophilous form and func- 
tion of the typical Labiates, although it is sometimes visited 
by flies and lepidoptera. On account of the protection of the 
helm, the pollen is not easily collected by Halictus, which neg- 
lect the flowers with receptive stigmas. It is accurately ap- 
plied to the backs of insects sucking the honey. The tubesare 
from 6 to 8 mm. long, which indicates an adaptation to long 
* See Miller: Fertilization of Flowers. 
