As the summer comes to a close, keep an eye out for Corallorhiza odontorhiza beginning to bloom its small reddish-purple flowers with a white purple-spotted lip. Commonly called autumn coralroot, this unique orchid is one of 11 other species of terrestrial orchids and is native to the eastern and central U.S. as well as some parts of Canada and Mexico. Before blooming, these orchids have green bulb-like structures hanging off the base of stems that peel back and reveal flowers in the fall, but depending on where you are in the country, these flowers might not bloom at all! You might be wondering then, how are they pollinated? Well, this subspecies, Corallorhiza odontorhiza var. odontorhiza is able to pollinate itself! This means that the pistol and the stamen of the plant are able to make direct contact with each other to create seeds.

A closeup of a yellowish plant with purple tips

Corallorhiza odontorhiza (autumn coralroot); Photo Credit: Christine Danforth

Another unique trait of not only this species, but the entire genus is that they are all myco-heterotrophic, meaning that they rely primarily on mycorrhizal fungi to feed them rather than photosynthesis. However, some species are able to photosynthesize to a limited extent. These plants are perennial but only bloom between August and October, so be sure to keep an eye out for these little beauties on trails and in forests this fall!

If you see something blooming, leafing out, ripening, or otherwise changing in your woods, send us photos (forestsforthebay@gmail.com) to include in next month’s Forests for the Bay newsletter for more phenological fun!

This month’s What’s Poppin’ was written by 2024 Environmental Projects Intern, Alex DeBuclet.