HERBACEOUS VEGETATION OF COAST PLAIN. 119 



suburbs of Mobile furnished sticks of merchantable timber 30 to 40 

 feet in length, none of them having reached an age of over 60 years. 

 Mesophile herbaceous plant associations (Rynckospora formation). 

 The terrace of sandy loams extends over the larger part of the coast 

 plain. The ground being almost perfectly level and underlaid by a 

 compact, somewhat impervious subsoil, is consequently more or less 

 deficient in drainage, and being covered with a dense sod formed by 

 the roots and rhizomes of low, perennial monocotyledonous plants, the 

 ground remains damp and the decomposing vegetable matter, under 

 the influence of sun and wind, is converted into an acid humus, giving 

 rise to a peaty soil. This damp, mucky soil, in a semiboggy condition 

 during seasons of rain, supports a vegetation of low, grass-like plants, 

 mostly of the sedge family or sour grasses (Cyperaceae) of various 

 genera, which in number vastly predominate over the true grasses 

 (Poaceae), rushes (Junci), and golden-eyed grasses (Xyridaceae), which 

 find their home in the flat, damp pine barrens of the plain. Horn 

 rushes (Rynchosporae) largely prevail over the other representatives 

 of the sedge family, and numerous species of this extensive genus, 

 almost exclusively confined to eastern North America and the adjacent 

 tropical zones, make up the largest portion of the sod vegetation, thus 

 forming a more or less compact plant formation highly characteristic 

 of this region. Among the mesophile associations which inhabit the 

 scantily shaded, frequently open plain, with its sour, damp, shallow, 

 and during the rainy seasons more or less boggy soil, there is found in 

 many localities a tiny creeping peat moss (Sphagnum, imbricatum) and 

 other short-stemmed species (S. compactum, S. intermedium), which 

 are able to resist the effects of occasional droughts. The following 

 Cyperaceae are typical, and predominate on the flat expanse of this 

 terrace of the plain: 



Rynchospora plumosa. Rynchospora divergens. 



Rynchospora pusilla. Rynchospora microcarpa. 



Rynchospora rariflora. Rynchospora gracilenta. 



Rynchospora multiflora. Rynchospora cymosa globularis. 



Rynchospora cymosa. 1 Rynchospora oligantha. 1 



Rynchospora ciliaris. Kobresia odorata. 



Rynchospora baldwinii. Kobresia monocephala. 

 Rynchospora chapmani. 



With these are found the following rushes: 



Juncus dliottii. Juncus marginatus aristulatus. 1 



Juncus diffusissimus. Juncus bufonius fascicularis. 



Juncus marginatus. * 



Grasses of the same region are preferring the low flats with a more 

 damp, sandy soil: 



Andropogon mohrii. Sieglingia poaeformis. 



Andropogon tetrastachyus. Manisuris corrugata. 



Paspalum praecox. 



1 Found also in Carolinian area. 



