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Tennessee Wildlife Resources Agency
Ellington Agricultural Center
440 Hogan Road
Nashville, TN 37220
(615) 781-6500
Endemic Bladderpods-Unusual and endemic rare plant species

Paysonia perforata (Spring Creek Bladderpod) and Paysonia stonensis (Stones River Bladderpod) are herbaceous annuals of the Brassicaceae, or mustard, family. Both of these delicate white flowers with floating seed pods are rare plant species endemic to the Central Basin of Tennessee.

Spring Creek Bladderpod is listed as federally endangered. Populations are known only from Wilson County in the Spring Creek, Barton’s Creek, and Cedar Creek drainages near the city of Lebanon. The Stones River Bladderpod is listed as state endangered, with all occurrences located in Rutherford County along the West Fork and East Fork Stones River near Walterhill and Lascassas.

Emblematic of problems affecting rare plant species

These two bladderpods are emblematic of the problems that beset many declining plant species in Tennessee: they have a limited range, which has been significantly reduced by loss of habitat—in the case of bladderpods, conversion of cultivated land to other uses, including development. Both species, which to the untrained eye can look quite similar, grow in similar habitats: disturbed areas such as agricultural fields, open pastures, and roadsides.

Today, both species tend to prefer cultivated floodplains that generally remain too wet to be worked until late April. This allows them to set fruit in late April and May. Annual flooding and/or some type of disturbance regime, such as properly timed agricultural practices, are both important for Stones River and Spring Creek bladderpods. Disturbance can also be caused by grazing animals that trample the soil.

The primary threat to these bladderpods is changing land use, including the conversion of annual cropland to fallow pasture where grasses such as fescue may outcompete them. Other threats occur if farmers begin cultivating fields earlier in the year before the plants have flowered and set fruit or if pre-emergent herbicides kill dormant seeds in the soil.

Where the bladderpods are . . .

Many of the occurrences of Stones River Bladderpod are located within the J. Percy Priest Reservoir and Wildlife Management Area owned by the U.S. Army Corp of Engineers (USACE). TDEC owns one property near Walterhill. A cooperative management agreement for Stones River Bladderpod has been established between the TDEC, the USACE, the U.S. Fish and Wildlife Service (USFWS), and the Tennessee Wildlife Resources Agency (TWRA). The purpose of the agreement is to provide long-term protection of Stones River Bladderpod by providing for the sustainable management of viable populations on USACE property.

In contrast, occurrences of Spring Creek Bladderpod are located mostly on privately owned lands. TDEC has contacted all landowners with occurrences of Spring Creek Bladderpod, and they allow the TDEC Natural Heritage Program to access their property to monitor the populations each spring. Cooperative management agreements have been developed between TDEC/USFWS and the City of Lebanon, Cracker Barrel Headquarters, and TRW Automotive Plant. The USACE owns one property that is leased for agriculture. Again, the purpose of the agreements is to provide long-term protection of Spring Creek Bladderpod by providing for the sustainable management of viable populations on their property.

There are two other species of Paysonia in Tennessee: P. lescurii (Lescur’s Bladderpod), which is not rare in Tennessee, and P. densipila (Duck River Bladderpod), which is state listed as Special Concern. Both species have yellow flowers and small round seed pods. P. densipila occurs in Middle Tennessee and P. lescurii occurs in Tennessee and one county in Kentucky (now believed to be extirpated). It is interesting to note that in some areas of the West Fork of the Stones River, the Duck River and Stones River Bladderpod populations overlap, and hybrid cream-colored flowers result!

Calling all botanists! Here’s how to tell them apart...

The two species are very similar in appearance. The seeds germinate in the late summer and fall forming rosettes, and then flower in spring. Both have white flowers with yellow centers, but the main distinguishing characters between the two species is the fruit, a round shaped silique (long, narrow seed capsule) that floats--hence the name bladderpod. Siliques of the Stones River bladderpod are densely hirsute (hairy), and slightly depressed globose with valves glabrous, or smooth, on the interior and hirsute styles. Conversely, siliques of Spring Creek bladderpod are glabrous (smooth) to very sparsely hirsute, pyriform (pear-shaped), with valves very papery and densely pubescent (fuzzy) on the interior and glabrous styles. The seeds can remain viable in the soil for a long time.

View or download an illustrated factsheet about Tennessee bladderpods

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