I saw a honey bee on some Purple Clover yesterday (some call it Red Clover), so let’s add it to the list of honey bee friendly flowers: Trifolium medium, also known as Zigzag Clover. That’s my best guess, anyway.
Honey bees can’t access the nectar in Purple/Red Clover as well as they can from White Clover, so it’s not something I’d go out of my way to plant, but neither will I mow it down if it’s growing in my lawn.
JUNE 30, 2016: I saw Purple Clover in blossom as early as June 15th this year.