JAN. 1907. WISCONSIN FLOWERS AND THEIR POLLINATION. 
41 
B. Aves. 
(5) Trochilus colubris h., s. 
Bumble-bees are the most important visitors. The visits of our 
humming-bird (Trochilus colubris) are of interest and have been 
discussed at the beginning of this paper. 
Salotnonia commutata (R. & S.) Britton. Smooth Solomon's Seal. 
This plant, the Polygonatum giganteum Dietr., is much larger 
than the one just referred to, reaching in our region a height of 
10 to 15 dm. Its flowers appear later than those of the other 
species, from June 7 to July 3. Robertson (20) has considered 
this species in connection with a review of the genus. The speci- 
mens studied in our locality differ in several points from those 
of southern Illinois as described by Robertson. There are two 
to five flowers in a group. The tube is about 17 mm. long, and 
has a diameter of 4 mm. at the mouth and 6 mm. in the middle. 
The teeth of the outer perianth-divisions are hardly more reflexed 
than those of the inner, they are all nearly erect. The flowers are 
homogamous, stigma and anthers becoming mature as soon as the 
tube opens. In the Illinois plants (Robertson) the style is too 
short to touch the anthers, thereby excluding spontaneous self- 
pollination. In our specimens the style with its stigma either 
reaches up between the anthers as in 5*. hiiiora, or it even sur- 
passes the anthers by at least i mm. In the latter case cross-pol- 
lination through insects may be more easily accomplished than in 
S. hiHora, on the other hand spontaneous self-pollination may 
take place when the pollen falls. In the plants of our surround- 
ings therefore two different ways are open to spontaneous self- 
pollination. 
Nectar is produced by the septal glands of the ovaries, but in 
addition to this the tissues of the inner surface of the tube are 
very juicy and yield droplets of a sweet liquid when punctured 
by the mouth parts of the visiting insects. Even the inner surfaces 
of the teeth (tips of the perianth-division) w^hich are dry imme- 
diately after the opening of the tube show such droplets after 
having received the attention of bees, and I have several times 
seen the short-tongued bees figuring in the list below (Halictus) 
obtaining sweets around the mouth of the flower. 
In our region Salomonia coinrnufata is andromonoecious. I 
20. Chas. Robertson. Loc. cit., p. 268. 
