APRIL, 1900. GRAENICHER— FERTILIZATION OF FLOWERS, ETC. 
73 
The Fertilization and Insect Visitors of our Earliest Entomophi- 
lous Flowers* 
By Dr. S. GRAENICHER. 
Among the first plants appearing in our neighborhood in early 
spring, only those species will receive our attention whose flowers 
rely more or less on the co-operation of insects to secure fertiliza- 
tion, and which for this reason are called entomophilous flowers. 
The few species of anemophilous or wind-pollinated plants, 
blooming at the same time of the year, as for example our species 
of Alnns (alder) and Corylus (hazelnut), will, therefore, not 
come within the reach of these considerations. 
In a small piece of open woods along the banks of the Menomo- 
nee River and opposite the grounds of the County Insane Asylum, 
two small plants may be observed together, one of them — Trilliiun 
nivale, Riddell (dwarf white trillium) — opening its flowers two 
or three days in advance of the other — Erigcnia hulhosa, Nutt, 
whose popular name, harbinger-of-spring, has been selected in 
accordance with its early arrival. Under extremely favorable 
circumstances, the first flowers of both species may be expected 
towards the end of March. The spring of 1898 was remarkable 
in this respect, as it presented us with the first flowers of Trilliinn 
nivale on March 26th, and with those of Erigcnia hulhosa on 
March 29th. When spring puts in a late appearance, however, 
the opening of these flowers may be delayed as late as the second 
week in April. This was the case last year (1899), when the first 
flow^ers of Trilliinn nivale were not observed previous to the nth 
of April and those of Erigcnia hulhosa on April 12th. 
Both plants occupy the same position in the soil, and bloom 
synchronously. The families to which they belong, produce, as 
a rule, entomophilous species, and for this reason the cpestion 
arises, whether these two species enter into competition with each 
other for the visits of any of the anthophilous (flower visiting) 
insects, flying at this early period. 
The plant of Trillium nivale, Riddell, a member of the Lily 
family (Liliaceae) , usually attains a height of 5 cm. and bears, as 
is characteristic of the genus Trillium, a single terminal flower, 
arising from a whorl of three leaves. The flower of our species 
holds an erect position on a pedicel of 8 mm. length, and has a 
corolla of three white, recurving petals, giving the flower a 
diameter of 15 mm. There are two rows of stamens surrounding 
