from the November 15, 2009 Newsletter issued from
Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
MEXICAN WILD PETUNIA
Last year in June in Mississippi I introduced you to a Wild Petunia, genus Ruellia, which you can still see at http://www.backyardnature.net/n/h/ruellia.htm.
Here, outside my bungalow door where I stayed at first, there was a different Wild Petunia -- same genus but different species -- emerging between concrete tiles forming a sidewalk to my door, as shown below:
That's RUELLIA NUDIFLORA and it's fascinating to flip back and forth between pictures of the Mississippi one and this one, noting similarities and differences. The flowers are very much alike, but they're differently arranged. The Mississippi species bunches them together at the top of the plant while the one outside my door presents them in an open cluster, each blossom having its own long, slender stem, or pedicle.
This is one reason I enjoy paying attention to the classification of organisms: Seeing how species of a genus differ from one another is exactly like savoring a fugue's "variations on a theme." So, here we have a Ruellia song first expressed in a Mississippi variation, and then in a Yucatan one.