The flower expects the bee.

March 18.

Examining the skunk-cabbage, now generally and abundantly in bloom all along under Clamshell, I hear the hum of honeybees in the air, attracted by this flower. They circle about the bud at first hesitatingly, then alight and enter at the open door and crawl over the spadix, and reappear laden with the yellow pollen.

What a remarkable instinct it is that leads them to this flower! The first sunny and warmer day in March the honeybee leaves its home, probably a mile off, and wings its way to this warm bank. There is but one flower in bloom in the town, and this insect knows where to find it. You little think that it knows the locality of early flowers better than you. You have not dreamed of them yet. Yet it knows a spot a mile off under a warm bank-side where the skunk-cabbage is in bloom. No doubt this flower, too, has learned to expect its winged visitor knocking at its door in the spring.

I think there would be no surer way to tell when a flower has bloomed than to keep bees and watch when they first returned laden with pollen. Probably with a microscope you could tell exactly when each of the bee-frequented flowers began to bloom throughout the year.

H. D. Thoreau, Journal, March 18, 1860

No doubt this flower, too, has learned to expect its winged visitor knocking at its door in the spring. See September 29, 1856 ("How surely . . .the bidens, on the edge of a pool, prophesy the coming of the traveller. . . that will transport their seeds on his coat."); February 19, 1854 ("The mind of the universe . . ., which we share, has been intended upon each particular object. All the wit in the world was brought to bear on each case to secure its end.”); July 29, 1853 (“The insect that comes after the honey or pollen of a plant is necessary to it and in one sense makes a part of it”)

All along under that bank I heard the hum of honeybees in the air, attracted by this flower. Especially the hum of one within a spathe sounds deep and loud. They circle about the bud at first hesitatingly, then alight and enter at the open door and crawl over the spadix, and reappear laden with the yellow pollen. What a remarkable instinct it is that leads them to this flower. . .  This is the only indigenous flower in bloom in this town at present, and probably I and my companion are the only men who have detected it this year; yet this foreign fly has left its home, probably a mile off, and winged its way to this warm bank to the only indigenous flower that has been in flower for a fortnight past . . .  There is but one indigenous flower in bloom in the town, and has been but one for sixteen days past, and probably this is the only one which the honey- bee can use, and this has only been detected hitherto by the botanist; yet this imported insect knows where to find it, and is sure to be heard near it . . .The first sunny and warmer day in March the honeybee comes forth, stretches its wings, and goes forth in search of the earliest flower . . . You see a fly come forth from its hibernaculum in your yard, stretch its wings in the sun and set forth on its flowery journey. You little think that it knows the locality of early flowers better than you. You have not dreamed of them yet. It knows a spot a mile off under a warm bank-side where the skunk-cabbage is in bloom. No doubt this flower, too, has learned to expect its winged visitor knocking at its door in the spring.