In the northern part of its Atlantic coast range, sea oats becomes dormant in winter. 

 The leaves appear as if dying, and in spring they are replaced by new leaves (Wagner, 1964). 

 In south Texas there is no such obvious period of dormancy, although some loss of color 

 occurs in winter as aging leaves become senescent; generally, the plants remain green year 

 round. There is a noticeable greening-up in early March, as new tillers are produced in 

 abundance. Tillering may occur in any month, particularly as a response to burial by sand. 



In May, flowering culms begin rapid growth and mature during summer; the spikelets 

 remain on the panicle until removed by the wind in fall and winter. Wind also plays a 

 dominant role in distributing the spikelets. The seed has a period of dormancy; cold-layering 

 over winter overcomes two inhibitors to germination (Wagner, 1964). However, many of the 

 ovules abort, and on the average, only two caryopses are found per 10 to 12 flowered 

 spikelet (Westra and Loomis, 1966). 



(d) Ecology. Sea oats is abundant on the foredune complex, from the backshore 

 and foredune foreslope leeward to the backslope, all along the south Texas coast. It is one 

 of the most characteristic plants of Padre Island. On the foreslope and backshore, it occurs 

 alone or with a few other species adapted to accumulating sand; on the middle and behind 

 the dune, it is found with a variety of less specialized species. Sea oats also occurs regularly 

 in disjunct populations on low, vegetated hummock dunes in mid-island, and on dunes near 

 the Laguna Madre shore. 



Wagner (1964) reported that uptake of the chloride ion by sea oats leaves is minimal, due 

 to a thick cuticle and other xeromorphic features. Oosting and Billings (1942) explained the 

 zonation of three dune species of the east coast (sea oats, seacoast bluestem, and 

 saltmeadow cordgrass) with respect to tolerance to windborne salt and moisture 

 requirements. Sea oats, which grows on the highest elevations and on the windward slopes, 

 has the lowest water requirement of the three species and is resistant to salt spray. Cordgrass 

 is more resistant and can withstand total saltwater immersion with no apparent effects. 

 However, saltmeadow cordgrass has the highest water requirement of the three species. 

 Seacoast bluestem is the least resistant to salt spray, which explains why it is found on the 

 foreslope in more protected depressions. These three species are similarly zoned in Texas. 

 Seneca (1972a) found an inverse linear relationship between seedling growth and substrate 

 sabnity. Based on seedling growth response, he showed that the order of decreasing salt 

 tolerance of four east coast dune grasses is saltmeadow cordgrass, shoredune panicum, sea 

 oats, and American beachgrass. 

 2. Methods of Propagation. 



a. Mode of Propagation: Direct Seeding. A substantial reduction in stabilization cost 

 could be realized if direct seeding would produce a stand of grass. Seeding was attempted 

 for 3 years using sea oats and bitter panicum seed. Bitter panicum seed is reportedly sterile, 

 although one trial planting in April 1972, germinated 6 weeks later. Seeding tests included: 

 (a) planting at different locations on the beach, hurricane overwash channels, and areas of 



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