JAN. 1907. 
WISCONSIN FLOWERS AND THEIR POLLINATION. 
23 
FAM. LILIACE^. 
Allium tricoccum Ait. AVilcl Leek. 
This plant is remarkable from the fact that the rather large 
leaves make their appearance quite early in the spring, but dry 
up and disappear before the blooming time sets in. The latter 
lasts from July ii to August 15. There are about fourteen green- 
ish-white inconspicuous flowers on short pedicels forming an. 
umbel at the end of a scape of about 22 cm. in length. The 
perianth-leaves are only 4 to 5 mm. long, they remain in an erect 
position with their tips inclining towards the stamens, the light 
yellow anthers of which are just lifted above the perianth-leaves. 
From the middle of the 3-parted ovary arises the erect slender 
white style with its simple stigma. The flowers are proterandrous. 
At first the three anthers of the inner row shed their pollen, and 
at this time the style has reached only two-thirds of its length. 
Later on while the outer anthers are dehiscing the style becomes 
fuUgrown and the receptive stigma is on the same level with the 
anthers. The first flower of an umbel is located centrally, the 
process of blooming therefore progresses from the center to the 
margin. Nectar is secreted by septal glands and appears as a 
drop in each of the furrows about half way up. It is concealed 
between the furrow and the broadened base of the corresponding 
filament and, besides, the erect position of the perianth-segments 
also assists in hiding it from view. No odor is emitted by these 
flowers. 
Although in an older flower a receptive stigma may be present 
together with pollen on the outer anthers there is hardly a possi- 
bility of spontaneous self-pollination on account of the upright: 
position of the flower and the distance between the stigma and the 
outer anthers. 
Insects engaged in sucking nectar push their heads in between 
the stigma and the introrse anthers, and become dusted with 
pollen on the sides of their heads. Their visits to different flowers 
result in most instances in cross-pollination. Bees are the main 
visitors, as seen from the following list : 
A. Hymenoptera 
Apidae: (i) Apis mellifera L. worker, s. ; (2) Bombus con- 
similis Cr. worker, s. ; (3) Alcidamea producta Cr. female, s. ; 
