The aptly named bee-bee tree, Tetradium daniellii, is the place to be if you like bees. Standing next to one of the Arnold Arboretum’s four specimens when this tree is open for pollinator business in mid to late summer, is not just a visual experience, but also an auditory one. There are so many bees (and bee species) collecting copious nectar and pollen from the thousands of small white flowers, that the whole tree feels like it is vibrating.

The bee-bee tree harkens from Korea and China and the first Arnold Arboretum seeds arrived from Korea in 1905, courtesy of John Jack, a remarkable dendrologist, plant explorer and teacher whose career spanned roughly 50 years at the Arnold (read about him here). Tetradium daniellii has an unusual sexual system in that some individual trees only produce pollen from unisexual male flowers, while other individual trees produce unisexual male and female flowers (monoecy), with the male flowers opening first and the female flowers opening only after the male flowers are done (to prevent self-pollination).

Images of bee-bee tree flowers, fruits, and seeds by Ned Friedman

Upper left photo, a (non-native) giant resin bee and a (non-native) honey bee on some open male flowers with yellow anthers filled with pollen (126-67*A—this is a great specimen to visit just off of Bussey Hill Road near the birch collection). Upper right, a honey bee with huge pollen baskets on the hind legs. The female flowers will form beautiful sets of red follicles (lower left) in September that will split open in October to reveal small jet-black seeds (lower right). All in all, a great botanical and entomological place to hang out.