A Spotlight on Silveus’ Dropseed: Tracking a Rare Species and its Associated Communities in Big Thicket and Beyond

Silveus’ dropseed (Sporobolus silveanus) in the understory of the sodic wet flatwoods community in Lance Rosier unit, Big Thicket National Preserve.

NPS/GULN

Summary and Highlights

• The rare bunchgrass Silveus’ dropseed has an affinity for unusual soils, frequent fires, and small, circular landforms called mima mounds. The species was first discovered in 1941 during a collection trip in the Big Thicket region, and although documented during the 2007 plant inventory for Big Thicket National Preserve, it had not been seen there since then. Recent surveys by NPS staff from the park and the Gulf Coast Inventory and Monitoring Network turned up one previously-known population and several newly discovered localities. These are primarily in a rare habitat type called sodic longleaf pine flatwoods.

• Outside of Big Thicket, the species is a key member of several other unusual types of prairies, glades and savannas that are found almost exclusively in eastern Texas and western Louisiana.

• This perennial grass likely belongs to a class of southeastern bunchgrasses that have fire-stimulated reproduction, which means on top of its overall rarity, the species is losing even more ground in fire-suppressed habitats.

• Learning how to tell Silveus’ dropseed apart from lookalikes, understanding its habitat associations, and carefully mapping its distribution in Big Thicket will help the park protect this unique native grass and its surrounding rare plant communities.

Want to Learn More?

Click the link below to learn more about the importance, history, and recent rediscovery of Silveus’ dropseed in Big Thicket National Preserve. In the full article, you'll be introduced to the rare and special plant communities where the species can be found, find out how the species can be identified in the field, and learn how the species is being managed for and protected elsewhere in Texas and Louisiana.

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Special Topic Brief on Silveus' Dropseed at Big Thicket National Preserve by the Gulf Coast Inventory and Monitoring Network

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