Saturday, March 21, 2015

Spring Bartonia; Coastal Plain Endemic


Bartonia verna flowers (03/11/15)
Spring Bartonia (Bartonia verna) is an unexpected member of the Gentian family that appears in early spring. One of the many species first discovered by Andre Michaux, populations are restricted, or endemic, to the outer coastal plain of the southeastern US. The northernmost range consists of a single population located near VA Beach (Belden etal. 2004, reported in Castanea). Over half of the states where it has been documented consider it to be rare, including North Carolina.  A couple of the other states (MS, AL) have not explicitly considered its rarity, but like surrounding states it is almost certainly very restricted in those areas; Florida is the only state where the species is widespread (http://plants.usda.gov/core/profile?symbol=Bave2)


Spring Bartonia habitat at a site in South Carolina (03/11/15);
Pond Cypress depression pond with extensive standing water at flowering time
Sorrie & Weakley 1999 consider Bartonia's range generally synonymous with longleaf pine. The local habitat often includes wetland margins such as the example shown above on the Francis Marion National Forest.  The flowering Bartonia individuals located at this site occurred adjacent to pitcher plants, especially the Hooded Pitcher (Sarracenia minor), and Peanut-Grass (Amphicarpum muhlenbergianum). 
Bartonia verna multi-floral stem just opening

Bartonia verna in several inches of standing water; amidst brown stems of  Peanut-Grass




All Bartonia species (we have 3 in our area) are similar in having reduced leaves and root characteristics which may suggest a dependence on mychorrizal relationships to gain nutrients. Although B. verna has not been studied, Cameron & Bolin (2010) found that Bartonia virginica plants were enriched in carbon and nitrogen relative to surrounding vegetation and suggest that species is at least partially mycoheterotropic.

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