Should you have come across this blog before you know that I am apt to wax poetic (or should that be quixotic) about my arch nemesis the air potato (Dioscorea bulbifera). Well just to add insult to injury, the air potato’s near relative has found its way to our little Back Woods. I give you the “winged yam” Dioscorea alata!
And yes it has wings. They have extra tissue (wings) jutting out from the edges of their squared stems and petioles. This differs from the air potato which has smoother angled stems and petioles that are not as noticeably squared.
The elongated bulbils of the winged yam appear in pairs at the leaf axis and whereas the air potato bulbils appear in pairs or singularly and are rounded.
The leaves of the winged yam are heart shaped like the air potato but appear to me more elongated. The notable key difference between the species is that the winged yam leaves are opposite on the stem and the air potato leaves are alternate (appear singularly) along the stem.
Interestingly, the winged yam twines counter clockwise around supports while the air potato twines clockwise around supports.
Like its relative the air potato, the winged yam is a non native invasive exotic species and listed as a Category I species in Florida meaning; “These are invasive exotics which are altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives. This definition does not rely on the economic severity or geographic range of the problem, but on the documented ecological damage caused.” FLEPPC
The Florida Exotic Pest Plant Council (FLEPPC) has a nice id sheet on winged yams found here: http://www.fleppc.org/ID_book/Dioscorea%20alata.pdf