e. Ideally Suited Species. The two remaining grasses, sea oats and bitter panicum , were 

 selected as the most ideal species of either natives or exotics. Bitter panicum is more 

 desirable because of higher transplant survival rates, longer planting season, ease of 

 harvesting, and the tendency to form a uniform dune profile. The general life history, 

 morphology, and ecology of these species in south Texas are summarized below: 

 (1) Bitter Panicum (Panicum amarum). 



(a) Geographic Range. Occurs along the Atlantic and gulf coasts from 

 Connecticut south to the Rio Grande, and has been reported from every intermediate State 

 including both coasts of Florida (Palmer, 1972). 



(b) Morphology. Bitter panicum is a strongly rhizomatous perennial grass, 

 growing by branching at the nodes which are scattered along the length of the culm (see 

 App. B for definitions of grass terminology). The internodes are long (Fig. 19); the sheaths 

 are longer than the internodes and are not strongly overlapping. The inflorescence is a 

 contracted panicle, with appressed main branches. Sheaths and blades are usually dark 

 green, somewhat glaucous and glabrous. Blades are up to 1.5 feet long but are usually about 

 half this length. 



(c) Growth. Growth is from primary shoots, lateral shoots (aerial nodes), or 

 tillers (subterranean nodes). In a typical foredune habitat, drifting sand often covers part of 

 the exposed culm, and the covered lateral shoots root at the nodes as do rhizomes or 

 stolons. In areas of light sand accumulation, the exposed parts of a mature primary culm are 

 over 1 yard long and include 10 or more nodes; in areas of heavy sand accumulation, only 

 the terminal leaves are visible. Schematic growth of a single-culm vegetative transplant of 

 bitter panicum is shown in Figures 20 and 21. The clump will eventually expand vertically 

 and horizontally in all directions by a continuation of the same process. At the perimeter 

 are the laterally spreading tillers, while in the center of a clump are the more vertical mature 

 primary culms. Mature primary culms may persist more than 1 year with little additional 

 growth if not buried. 



Greatest vigor occurs where blowing sand accumulates around the plant. The sand either 

 mechanically or nutritionally stimulates the growth of new shoots and tillers which keep 

 pace with the accumulation. If the sand supply is choked off, as on the leeward parts of a 

 foredune, the plants appear nutrient-deficient after several years. Cover decreases, and the 

 plants appear semidormant even in summer, putting out a minimum of new growth. 

 Although such a stand appears to be declining, a new deposit of sand will quickly stimulate 

 growth. 



The growing season in south Texas coincides with the prevailing weather for that 

 particular year. During the warm winter of 1973-74, some active growth occurred in all 

 months although from mid-December to mid-February most plants in areas of light sand 

 accumulation appeared dormant. Most leaves died, leaving only the exposed culm with 

 perhaps a few green apical leaves. Tillering and shoot growth from old culms generally 



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