Hackberries are one of my favorite street-side trees. Their warty bark is entertaining year ’round, and I always enjoy the assortment of galls and growths found on their leaves and twigs. (I blogged about Hackberry Nipple Galls here.) On yesterday’s walk through south Oak Park, I noticed that Hackberry fruits are ripening on a few neighborhood trees:
Only a few fruits on this tree were ripe, but there were many raisiny purple Hackberry fruits on the sidewalk (perhaps knocked there by recent storms).
If you bite gently on a ripe Hackberry fruit, you’ll often taste a bit of sweetness (which varies tree to tree). That’s why some folks call these “Sugarberry” trees. Just don’t bite too hard! Inside the thin fruity coating is a seed that’s hard as rock. The seed actually contains a bit of calcium carbonate, which makes up limestone rock. That’s one reason Hackberry seeds are readily preserved in soils. I’ve even found 40-million-year-old Hackberry seeds buried in ancient soils in the Badlands of South Dakota and Nebraska (see examples here).
Like me, many birds eat Hackberry seeds in south Oak Park, including Robins, Cedar Waxwings, and Starlings. Last fall I watched a flock of Crows feeding in a Hackberry tree along Oak Park Avenue near Lincoln School.
Galls, fruits, fossils, and birds — no wonder I love Hackberries!
Here are links more information about Hackberries: