VEGETATION OF LITTORAL BELT. 129 
occupy almost alone the alluvial banks bordering the swamps, covered 
with the débris left behind after every overflow. 
LITTORAL BELT. 
This division of the coast plain comprises the outlying islands and 
the narrow strip under the influence of the salty tide. Either sandy 
or marshy, this Littoral belt presents three distinct formations in its 
flora: (1) The plant formation of the strand or sandy flat beach, with 
its shingle and salty pools; (2) the plant formation of arid drifting 
sands, (8) and lastly the salt marsh. 
Halophytic plant associations of the strand.—The strand or sandy flat 
beach, of moderate extent, as found in Baldwin County, washed by 
the more or less brackish water of Mobile Bay and the smaller inlets 
to the east of this sheet of water, is almost destitute of vegetation. 
The flora of the strand lining the Gulf shore, always moistened by 
the salt spray of the surf and flooded by high tides, is poor in individ- 
uals and species. The species found are, many of them, at home on 
tropical shores, and they constitute a very open association of sand- 
loving, salt-water plants (halophytes), similar to the Zpomocu. pes-capreae 
formation of tropical strands. This fine halophyte of the morning- 
glory family, from which this association has received its name, is not 
rare on our Gulf shore. Its interlaced stems form large patches, 
which at once attract the attention by the rich dark green of their 
fleshy broad leaves and by their large rose-purple flowers. Seswedum 
portulacastrum inhabits the shallow salty pools with Cahvle maritima 
geniculata, both frequent in the West Indies; also with va imbricata, 
a low shrubby perennial of southeastern North America, and Dondia 
(Sueda) linearis, common on the Atlantic and Gulf shores from New 
England to Florida and Mississippi. 
Xerophile plant associations of the dry sands of Mobile und Perdido 
bays.—The benches of loose white sand extending along the shore of 
Mobile Bay and the land-locked waters of Perdido Bay present a varied 
vegetation of sand-loving plants (psammophytes), which are so scat- 
tering, however, as scareefy to hide the snow-white sands. When 
viewed under the glare of the noonday sun, the dark-green foliage of 
the stunted live oak, with gnarled limbs, stands out in strong contrast 
with the glistening sands. The stiff, leathery, narrow leaves, shining 
above and hoary beneath, peculiar to this maritime form, afford a safe 
protection against the injurious effects of excessive transpiration dur- 
ing a long-continued drought, when the sand is heated by the scorching 
rays of the summer sun. 
The grasses are: 
Panicum repens. . Cenchrus incertus (sand bur). 
Panicum littorale. Cenchrus megacephalus (sand bur). 
Stenotaphrum secundatum (Saint Augus-  Sieglingia purpurea (purple sand grass). 
tine grass) . Sieglingia americana (Southern sand grass.) 
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