558 HARPER: PINE-BARREN VEGETATION OF MISSISSIPPI 
- The list of plants given below is of course far from complete, for 
there must be nearly a thousand species of flowering plants in 
the area examined. But it probably contains most of the trees 
and shrubs that could be found, and most of the larger herbs. 
In a quantitative analysis cf vegetation bulk is more important 
Fic. 1. Looking east across Bayou St. Martin, near southwest corner of Jackson 
County. Pine-barrens on both sides (Pinus Elliottii at edge, P. palustris on higher 
ground), passing abruptly, with no intervening fringe of shrubs or hardwoods, into 
brackish marsh vegetation consisting mostly of Juncus Roemerianus. (The absence 
of a strip of hammock vegetation at the edge of the marsh probably indicates that 
the fires which keep the pine forest clear of underbrush sweep right across the bayou 
through the rushes.) July 16, 1913 
than number of species or individuals, and the herbs too small to 
recognize from a moving train, however interesting they may be 
to systematists, probably constitute less than I per cent. of the 
total volume of vegetation. The difficulty of recognizing some 
plants from a train has been partly counterbalanced, however; 
by the fact that I spent several hours on the ground near the 
coast, where typical pine-barren plants are most abundant. 
To indicate as nearly as possible relative abundance, which is 
not necessarily the same as frequency, wherever a species was noted 
as abundant I have counted it three times in tabulating the returns, 
where common it is counted twice, and where rare it is not counted 
at all. (Even this does not do justice to the abundance of the 
