72 



Herbs (all weeds) 



Chauiaccrista robusta ( ?) Verbena angustifolia ( ?) 



Helenium temiifoUum Piaropus crassipcs 



Croton eapitatus 



The Prairies 



Dr. Hilgard distinguished three kinds of prairie in southern 

 Louisiana, all contiguous, namely, brown loam on the northeast, 

 gray silt on the west, and black calcareous on the south, next to 

 the coast marshes. I crossed all three, but on account of the 

 relatively small extent of natural vegetation remaining and the 

 inherent difficulty of identifying herbs from a fast train, on a 

 route traversed only once, I will not attempt to separate them 

 at this time. On the more southerly route the ground-watei 

 level is pretty close to the surface, and the railroad is built on a 

 low embankment most of the way, while on the other route, 15 

 or 20 miles farther north, the prairies are comparatively high 

 and dry (though not over 75 feet above sea-level), which prob- 

 ably makes as much difference in the vegetation as the compo- 

 sition of the soil does. 



The prairie country stretches westward from Opelousas and 

 Lafayette at the edge of the Mississippi bottoms to the bottoms 

 of the Calcasieu River, and like most prairies is almost perfectly 

 level. Toward the western edge, however, in the gray silt prai- 

 ries, there are numerous low mounds rising a foot or so above 

 the general level, which make the vegetation a little more diver- 

 sified than it would be otherwise. There are also quite a number 

 of strips and patches of timber, mostly along streams, so that one 

 hardly ever has an unobstructed view of more than two or three 

 miles in any direction. Eastward the trees are all deciduous, but 

 toward the west pines appear in increasing numbers, mostly 

 Piniis Taeda on the northern route and P. palustris on the south- 

 ern route. Where the prairie is bordered by deciduous forests 

 the boundary is sharp, but the edge of the pine forest is ill- 

 defined, prol)al)ly on account of fire, as on the Hempstead Plains 

 of Long Island.* 



* See Mem. Torrey Club 17: 271. 1918. 



