16 THE VEGETATION OF SHACKLEFORD BANK 



The interior of this portion of the island is covered by a very dense 

 vegetation, through which it is difficult to force a passage. The lower 

 ground possesses a black, impervious soil, constantly wet with rain- 

 water, and covered by a dense herbaceous growth. Around these fresh- 

 water swamps the sandy elevations are covered with shrubs and small 

 trees.i "Woody vines are especially abundant here, growing with a 

 tropical luxuriance which contrasts strangely with the desert-like aspect 

 of the beach formations.^ 



Between High Hill and Mullet Pond (see map) the sound is bordered 

 by salt marshes, which are overflowed at high tide. The vegetation here 

 is constant in character and appearance. A dense stand of Spartina 

 glabra, in which Salicornia amhigua is abundant, gives the marshes a 

 uniform grassy appearance. This association is invaded rarely, and then 

 only by Borrichia frutescens. 



Above • the level of ordinary high tides the marsh is given a more 

 varied aspect by the presence of a number of invading species. Of these, 

 Juncus Roemerianus is one of the first to appear. This is a large, tall 

 rush, the dark clumps of which dot the marshes here and there. Climb- 

 ing on the rush is usually to be found a narrow-leaved, slender herb, 

 Seuiera paliistris. Between the hummocks of Juncus occurs commonly 

 Gerardia maritima, forming purple patches on the level swamp. 



East of High Hill the ground is uniformly high, from 10 to 20 feet 

 ' above sea-level, and the sand strand is quite narrow. In this stretch 

 occurs open woodland, where the vegetation is not so dense as in the 

 thicket woodland farther west. The characteristic trees are Que reus 

 rirginiana, Q. phellos, Persea puhescens, Morus rubrci, and Ilex opaca. 

 While some of these trees are of considerable size, none of them attain 

 the dimensions of the same species on the less exposed mainland. Be- 

 tween them Ilex vomitoria (yaupon) is the usual shrub, here being beset 

 with numerous short thorn-like branches. Woody vines are conspicu- 

 ous, the species being identical with those mentioned as occurring occa- 

 sionally on the sandy plrteau bordering the sea beach. "^ 



At about the level of Wade's Shore the open woodland begins to be 

 succeeded by dune marshes. Here the black soil retains the rain-water, 

 which stands at a level of 6-12 inches, and which is brown in color like 

 the ''Juniper water" of the Dismal Swamp. These marshes are not of 

 great extent and lie on the seaward side, near the wall of advancing 

 sand. 



From this point to Cape Lookout both forest and swamp have dis- 

 appeared completely save for one or two small groves of live oak, which 



iFig. 4. 

 2Fig. 5. 

 3Fig. 7. 



