Our broad-leaf plantain
When I want to find out if a plant has been collected and recorded in Carroll County, I go to two sources: Atlas of the Vascular Plants of Arkansas (Gentry, et al., eds. 2013) which has county range maps for plant species known from Arkansas, and the bonap.org (the Biota of North America Program) which is an on-line atlas of county range maps for plants throughout the United States.
I was looking for information on common broadleaf plantain Plantago major, a well-known Eurasian weed found throughout North America and beyond. Imagine my surprise to see that it was not listed for the state of Arkansas in either of the atlases above.
The reason for that absence is simple. Rather than Plantago major, our common broadleaf plantain is actually a native species found throughout eastern North America, Plantago rugelii, also known as Rugel’s plantain, first described in 1852. Our common Rugel’s plantain is easily identified by the purple color of the stems at the base or leaves hugging the ground. The subtle differences between the two species have led to them being treated as one from a practical standpoint (as edible and medicinal plants), though taxonomists recognize the technical differences.
A letter published in the 1878 Botanical Gazette (Vol. 3, No. 1), J.J. Davis of Racine, Wis., shed lights on practical matters, “I find that people who are in the habit of indulging in plantain ‘greens’ have long known that there are two kinds; the Plantago rugelii, toothsome [edible]; the other Plantago major, bitter and unpalatable. They distinguish the Plantago rugelii by a character I have not seen mentioned: the leaf stalks being purplish toward the base, a character that holds up to observation and one easily distinguished.”
He reveals the ultimate arbiter of identity through a taste-test, “The eminently practical botanist, the old cow, accepts Plantago rugelii readily [as food] but rejects Plantago major after an olfactory test.”
In the late 1800s agronomists in Europe observed that the most prominent weed seed contaminant in red clover seeds imported from America were those of our native Plantago rugelii. It spread and has become a weed in northern Europe and has since occupied Africa, Asia, Australia, and New Zealand. The leaves have been universally adopted for topical treatment of wounds, bites and stings, microbial infections, and other uses, at least according to Nigerian researchers interested in developing the potential of this native American weed.