169] FLORA OF COLUMBIA AND VICINITY 27 



spp.), golden-rods (Solidago spp.), asters (Aster spp.), cone- 

 flowers {Riidbeckia spp.), and sunflowers {Helianthus spp.) 

 are present, but these are seldom purely riparian. More 

 truly so are Elephantopus Carolinianus and Actinomeris squar- 

 rosa. In open places the ragweeds {Ambrosia spp.), and tick- 

 seeds and sticktights {Coreopsis and Bidens spp.) are very 

 abundant. Along the Missouri river Senecio lobatus is com- 

 mon. 



D. Palustres. Plants of the palustrous zone. 



Of the three sub-floras that belong to this zone there are 

 members of but two, the paludose and the uliginose, the third, 

 that of the peat and sphagnous bogs, being wholly absent. The 

 distinction between the paludose or wet swamp, and the uligi- 

 nose or dry marsh, floras is often not clear. The palustrous 

 vegetation is rich in species, which are often of wide range. 

 Gramineae, Cyperaceae, Juncaceae, Polygonaceae, and Composi- 

 tae are especially common. The plants possess a soil exceed- 

 ingly rich in humus, but often cold and soggy from imperfect 

 drainage. The vegetation is rank and coarse, the annual herbs 

 often exceeding a man's height. With the exception of the 

 carices the blooming is chiefly aestival and autumnal. 



1. Palustres paludosae. Plants of the paludose subzone. 

 The paludose flora occupies wet and covered swamps. The 

 best examples lie along Roche Perche creek and at Brushwood 

 lake, but one, more accessible, occurs across Hinkson creek 

 south. This has of late been drained and denuded of trees, and 

 is hence gradually coalescing with the uliginose flats around it. 

 It occupies several successive old beds of Hinkson creek, the 

 stream being now far to the north. Since the intervening 

 ground is higher, the surface water tends to collect and thus 

 form a swamp, which until it was drained, had considerable 

 water. The flora is not uniform, the southern portion of the 



