The overall aspect of this area is that of a grassland plain. The variety of vegetation is greater here than in any of the other habitats on the island.
The land forms vary from almost level to a series of low ridges and hummocky surfaces. Some of the forbs present are beach morning glory, beach evening primrose, railroad vine, prairie senna, and gulf croton.īehind the belt of foredunes and occupying a major portion of the interior of the island is a low area of deep sand. The vegetation is a dense cover composed primarily of grasses: bitter panicum, sea oats, gulf dune paspalum, and dropseed. These dunes are fairly well stabilized by vegetation, except where wind, water, or human activity have destroyed the vegetation exposing dunes and transforming them into actively migrating forms. Landward of the beach along most of Padre Island is a ridge of vegetated coastal sand dunes, composed of sand blown from the beach by onshore winds. On the landward edge of the beach, a few salt tolerant plants such as glasswort, sea purslane, and seashore dropseed are established. Plant debris and seeds are continually washing up. Marine algae, particularly sargassum weed, are brought up onto the beach by ocean currents. The beach is almost entirely devoid of vegetation. The Gulf beach has a very gentle slope and is continually effected by factors such as wind, wave conditions, tides, storm surges, and human traffic in most areas. The only state or federally protected plant species, which is known to occur on Padre Island, is considered a species of concern: Roughseed Sea-purslane (Sesuvium trianthemoides). The following are the plant habitats to be found on the island and a few of the species to be found in each. Padre Island supports 75 plant families composed of almost 400 species.