Friday, May 3, 2013

Missouri Bladderpod

Missouri Bladderpod Up Close
The highlight of our recent plant survey was finding a small cluster of Missouri bladderpod, Physaria filiformis, formerly known as Lesquerella filiformis.  It looked like another little yellow flower nestled near a few buttercups until Linda Ellis recognized it as special.  This little beauty is extremely uncommon and has just been upgraded from endangered to threatened status.  Discovering it in a new location was a thrill.
"The Missouri bladderpod was added to the Federal List of Endangered and Threatened Plants on January 8, 1987 as an endangered species. As a result of this listing, the U.S. Fish and Wildlife Service prepared a Recovery Plan that identified priority conservation actions. Those actions include protecting and monitoring existing populations, surveying for new populations, habitat protection, and public education. Progress made toward recovery prompted the Service to reclassify the bladderpod from endangered to threatened in October 2003." US Fish and Wildlife Service
Seed Pod- Closeup
Bladderpods are members of the mustard family and have the typical rosette of leaves along the ground with the flower stems erect above, 4-8 inches above ground.  The leaves and the stems have a gray coloration due to a dense covering of fine hairs.  (See picture below)  The flowers have 4 tiny yellow petals and after opening, the oval seed pods develop, green but turning brown in the summer.   Each pod contains 4 seeds which drop to the ground, remaining dormant until they germinate in the fall, producing the small rosette of leaves that will remain all winter.

Note the fine hairs on the stem with a gray sheen
We made a field trip to a glade in 2010 specifically to see Missouri bladderpod.  Although only one day earlier in April than this plant survey, it was cold, rainy and otherwise miserable.  That day we eventually found a tiny patch of plants, their blossoms closed with their pods not yet formed.  It almost seemed like they were shivering like we were.

2010 - Cold Bladderpods  Click to enlarge
Missouri bladderpod seed can remain dormant in the soil for years, awaiting the right conditions.  As they are native glade plants, they are affected by weather and especially the shading of taller plants and grasses.  For this reason, they are particularly vulnerable to aggressive invasive species.  These factors account for the fluctuations in the numbers of plants on a given plot.  A study in 2005 demonstrated these fluctuations below.  One site  has been monitored for ten years. The number of individuals observed has ranged from zero to over three hundred thousand from year to year. Center for Plant Conservation


Management of glades for the preservation of bladderpod populations includes removal of invasive species, including cedars and the use of prescribed fire.  Efforts like these have paid off.
"The Missouri bladderpod is restricted to southern Missouri and northern Arkansas. It was probably never found beyond this range but was known from only nine sites in three counties when it was first listed as endangered in 1987. After additional surveys were conducted and actions undertaken to conserve the bladderpod, the number of documented populations increased to 61 sites in 4 counties in Missouri and 2 sites in 2 counties in Arkansas. US Fish and Wildlife Service
More on Missouri bladderpod in the MDC fieldguide and this video.


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