quote:
plants like willow or aspen trees provide loads of wonderful pollen, but no
nectar.

I almost wrote the same thing myself, but thought better, and consulted
"American Honey Plants" by Pellett.

Willow does produce nectar. It is produced very early in the season so most
of it is consumed, though they state:

"the bees sometimes store as high as 8 to 15 pounds per hive... the honey has
a pleasant aromatic taste not unlike that obtained from fruit blossoms"

"In Saskatchewan there is one willow, Salix bebbiana... the bees flock to it
in preference to dandelion... the plant is an exceedingly generous producer
of nectar [and] pollen."

pb