A Roseling By Any Other Name...

... continuing my look back to May 2011 and the excursion that Justin Thomas and I took to study the flora of South Carolina...

At Shealy's Pond Heritage Preserve, we came across this interesting spiderwort... but guess what... it isn't a spiderwort.  This is Piedmont Roseling (Callisia rosea), a plant of the southern Atlantic coastal plain and Gulf Coast, known from Maryland to Alabama and Florida. 

Don't allow that distribution description to fool you, though... aside from South Carolina, southern North Carolina, eastern Georgia, and central Florida, the county distribution of Piedmont Roseling is pretty spotty.  And this distribution is based on the species in the broad sense.  Taking a more liberal approach, Piedmont Roseling is found primarily in South Carolina and eastern Georgia, and Grassleaf Roseling (Callisia graminea) has its greatest county distributions in South Carolina, southern North Carolina, and Florida.  Most authors currently split Grassleaf Roseling from Piedmont Roseling based on the width of the leaf blades and the width of the blades in relation to the sheaths.  However, as noted by Faden (2000),

"The evidence that this [Callisia rosea] and the following two taxa [Callisia graminea and Callisia ornata] are species, instead of varieties or subspecies, is hardly compelling. It is a matter of the author's preference. The work of N. H. Giles Jr. (1942) clearly demonstrated cytological diversity within Callisia graminea, but the remaining taxa have never been investigated in the same detail. The taxa appear to hybridize when they come in contact."

"So you're telling me that this isn't a spiderwort??"  Well, if you must call it a spiderwort, I won't argue.  Piedmont Roseling is also called Cuthbertia rosea by some authors, and it was once known as Tradescantia rosea.  There it is... Tradescantia = spiderwort.  The flowers of species in the genus Tradescantia are subtended by large, leaf-like bracts, whereas those of species in the genus Callisia are subtended by inconspicuous bracts.  No matter how you treat it taxonomically, there is no denying that this is one good-looking little plant.

Should you want to find this attractive member of the day lily family (Commelinaceae), your best bet would be to search sandhills and dry, open woods and barrens with sandy or rocky soils.  It is also occasionally found along railroads and on roadsides, as well as in grassy meadows and swamp forests.

 

Faden, R. B.  2000.  Callisia. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. Vol. 22, pp. 187-190.

Looking Back...

Since I never posted on this blog about my spring botanical trip with Justin Thomas to South Carolina in May 2011, I figured that now would be as good of a time as any to start catching up.  I did post about our trip on Get Your Botany On! here, here, and here, so be sure to check out those posts as well.

In addition to the rare and wacky, and even on occasion the very showy, one of the things I enjoy most about botanical excursions around the country is seeing species that I'd previously never heard of in genera with which I am familiar.  The plant that is the topic of this post fits that description.  This is Houstonia serpyllifolia (aka Hedyotis michauxii), Thymeleaf Bluet.  At a quick glance, this species (particularly the 4-merous powder-blue flowers with yellow corolla throats) looks like the Quaker Ladies (Houstonia caerulea) that is widespread throughout the eastern United States.  Don't be fooled, though... one must take a closer look, especially at the distribution of leaves on the plant, to know that this is a species with a much more restricted geographical range and habitat requirement than that of Quaker Ladies. On Thymeleaf Bluet, or Mountain Bluet as it is also known, the leaves are tiny and nearly round, and they are distributed primarily on creeping stems from the base of the plant (leading to yet another common name, Creeping Bluet).  Quaker Ladies has leaves that are more spoon shaped in a basal rosette and sparsely distributed in an opposite fashion up the stems. 

As mentioned above, Thymeleaf Bluet isn't as common overall as Quaker Ladies.  In fact, the former is only known from a narrow band along approximately 500 miles of the Appalachian Mountains in nine states; in two of those states on the fringes of its range (Kentucky and Pennsylvania) this member of the Madder Family (Rubiaceae) is a species of conservation concern.

In addition to the foliage differences between Thymeleaf Bluet and Quaker Ladies, you would likely know you weren't looking at Quaker Ladies if you saw this plant simply by observing the habitat in which you were located.  Whereas Quaker Ladies grows in open woods, meadows, and grassy areas, Thymeleaf Bluet is found along streambanks and on rocks in streams, in rich woods, on damp slopes, and on spray cliffs in seepage areas.

In future posts this winter, I hope to highlight other plants from our spring foray that I didn't discuss on Get Your Botany On!.  Stay tuned!