KYBBY 2022 ID Tips: Know Your Woodland Stellaria!

(Cross-posted from the KNPS Wildflower Week BotanyBlitz journal)

In open calcareous woodlands of Kentucky, there are two relatively common native Chickweed (Stellaria) species you may encounter: Star Chickweed (Stellaria pubera) and Tennessee Starwort (Stellaria corei). They are very similar in overall appearance -- so similar that Tennessee Starwort was once considered just a variety of Star Chickweed, rather than its own species. But there is a fairly easy way to tell them apart when they're in bloom. Let's take a look!

Star Chickweed (Stellaria pubera)

(Left photo by @michaela_rogers, right close-up photo by @melanielinkperez)
Star Chickweed is a delightful spring wildflower with white, star-like flowers. In the close-up photo, check out the green calyx behind the petals. (Note: scroll down to the 4th photo here if you're not sure what the calyx is.) The sepals -- or individual leaf-like bracts that make up the calyx -- of Star Chickweed are always shorter than the petals. Now let's look at...

Tennessee Starwort (Stellaria corei)

(Left photo by @drdeforest, right close-up photo by @stephen_bucklin)
Pretty similar, huh? Once again, check out the close-up photo: look at those long, sharply pointed sepals! The sepals of Tennessee Starwort are as long as or longer than the petals. This is a diagnostic feature that you can use to distinguish between the two species.

Star Chickweed is somewhat more common throughout Kentucky than Tennessee Starwort (you can check out their county-level BONAP range maps here), but particularly for botanizers in the Bluegrass Region or Appalachian Plateau, either species could be seen on a woodland hike in spring. So if you see either and you're still not quite sure which it is, don't forget to include a good photo of the sepals in your iNat observation!

Posted on March 16, 2022 11:52 AM by vvoelker