04 February 2012

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.


Iwan Molgo said...

Hi Scott namestnik
My name is Iwan Molgo and doing a project On Callisia rosea, C.graminea and C. ornata.
I looking for populations were I can do some tissue sampling. Many herbarium voucher specimens are from the early 1900s and certain habitats do not exist anymore. Do you know of any locations where i might find these plants
Thanks in advanced

Scott Namestnik said...

Hello Iwan. We saw several plants of Callisia rosea in the parking lot at Shealy's Pond Nature Preserve. See https://www.dnr.sc.gov/mlands/managedland?p_id=74 for more information on the preserve. You should contact the South Carolina Department of Natural Resources regarding tissue sampling of the plants on their property. Hope this helps.


iwan said...

Thanks Scott