Sea oats (Uniola paniculata) — , native, iNat 131. The tallest and most photographed dune grass, reaching about eight feet, with flat, oval, scaly, brownish spikelets crowded into a nodding cluster on a smooth stem; it flowers in June and July and ranges along the coast from Virginia to Texas . It is the emblematic dune builder of Texas coastal literature, but the Texas form's seeds are essentially sterile and the plant spreads mainly by runners . It is listed as a dominant of Texas coastal dunes statewide .
Bitter panicum (Panicum amarum) — , native, iNat 50. A perennial warm-season grass four to eight feet tall, erect to sprawling, with smooth bluish leaves a quarter to half an inch wide and a narrow, contracted seed head twelve to fifteen inches long. Flowering runs from September into December; the plant is a sterile hexaploid and reproduces by tillers and rhizomes, spreading into open clumps. Cattle relish it and grazing once eliminated it from parts of the Texas barrier islands, but it reestablishes quickly once stock are removed . The Lady Bird Johnson Wildflower Center gives bloom months of August through October .
Gulfdune paspalum (Paspalum monostachyum) — , native, iNat 2. A perennial to about four feet in sandy, saline dune soils, blooming May through November . It is a dominant of the grasslands behind the dunes with seacoast bluestem and is named among foredune grasses at Padre Island National Seashore at Padre Island National Seashore . Few iNaturalist users photograph it, which explains the low count.
Seacoast bluestem (Schizachyrium littorale; the 1977 paper used S. scoparium) — , native, iNat 51. The most important species across the 1977 transects and a co-dominant of the coastal grassland statewide . A bushy bluestem recorded on the island under the name Anatherum tenuispatheum (maritime bushy bluestem, iNat 89) fills wetter swales; the TPWD classification lists the related Andropogon glomeratus in this system .
Seashore dropseed (Sporobolus virginicus) — , native, iNat 4. To about two feet, with greenish-white to purplish spikelets from June to November . It is the "dropseed" of Padre Island's foredunes and wind-tidal flats at Padre Island National Seashore and an associate of the saline prairie on the mainland . Telling it from sea oats: sea oats stand to eight feet with big, flat, nodding oat-like spikelets ; seashore dropseed is a knee-high grass with a slender, inconspicuous seed head .
Also on the dunes: coastal sandbur (Cenchrus spinifex, iNat 7) and red lovegrass (Eragrostis secundiflora, iNat 10), both listed in the TPWD dune-grassland system and, for the lovegrass, in the Padre Island grassland list at Padre Island National Seashore .
Observe responsibly
Wildlife, tides and access conditions change. Keep a respectful distance, do not feed wildlife, stay out of dunes and marked nesting areas, and use current official rules before fishing or handling any catch.