JAN. 1907. WISCONSIN FLOWERS AND THEIR POLLINATION. 
33 
honey-bee and a bumble-bee Bouibus consimilis, one of the species 
represented in the Hst given above. 
The bell-shaped greenish-yellow flowers are situated at the 
summit of a scape forming an umbel of three to six pendulous 
flowers directed to one side, and in addition to these we sometimes 
find two or three flowers lower down on the same side of the 
scape. The six perianth-leaves are recurved so as to give the 
fully developed flower a diameter of cm. Stamens, pistil and 
perianth-segments are all of the same length, from i8 to 20 mm. 
In the basal region the segment is folded together and forms a 
medial furrow of 2 mm. depth along the inner side, at the bottom 
of which nectar is secreted. The broadened base of the opposite 
filament covers the furrow and a canal of 6 mm. length is thereby 
constructed running down to the nectary. 
The style protrudes from the middle of the flower, but it is 
directed slightly downward and carries a broad flattened stigma. 
The anthers are about 5 mm. in length. They are kept well out 
of the way of the stigma, being arranged in a circle of 2 cm. 
diameter around the latter. Such an anther splits open laterally 
and within a short time along its entire length. In warm and dry 
weather this whole process of dehiscence may be accomplished 
within an hour. The flowers are homogamous. 
There is a slight possibility of spontaneous self-pollination tak- 
ing place through the falling of pollen on the stigma, but the 
flowers are adapted to long-tongued bees and bumble-bees (flying 
at this time of the year in the female sex only) are certainly the 
most efficient pollinators. Such a bumble-bee usually alights on 
the lowest flower of a group and after sucking and collecting 
pollen crawls up to the neighboring one. Cross-pollination or at 
least self-pollination is the outcome. The visits of the short- 
tongued bees mentioned in the list, (Halictus and Agapostemon) , 
are hardly of any use to the flowers, unless they alight on the 
stigma, but this is generally not the case. 
An interesting feature of these flowers is the arrangement by 
which they are more or less protected from unwelcome visitors. 
The bases of the filaments are well supplied with protruding hairs, 
and the same is the case with the perianth-divisions in their basal 
region alons: the outer surface, where they are close together. This 
renders it difficult for ants and all kinds of short-tongued insects 
to push their mouth parts from the outside in between the peri- 
