238 



Angelica atropurpurea L. Occasional, along margins. 



Slum cicutcefolium Gmelin. Occasional, in swamp margins 

 near bluffs on alluvial bottoms. 



Cicuta maculata L. Common, in places with the preceding. 



Gicuta bulbifera L. Occasional in margins of swamps. 



Utricularia vulgaris L. Rare in quiet backwaters, in the 

 more open places with alluvial ooze and underlying sand and 

 springs. 



Polygonum amphibium L. Common in shoal water, in 

 places, in the flooded bottoms and along margins of permanent 

 backwaters. Habitat usually dry at low water. Stems often 

 attaining a length of fifteen to twenty feet. 



Ceratophyllum demersum L. Abundant everywhere in shoal 

 and deeper waters, often above low-water levels, and at times 

 even encroaching upon channels where currents are main- 

 tained. It grows in patches and dense masses, sometimes 

 choking the smaller lakes from shore to shore. It occurs us- 

 ually on bottom of soft alluvium, which in some places forms 

 but a thin film above the hard sand beneath. It reaches the 

 surface in early summer, and grows throughout the warm sea- 

 son unless swept away by floods or seines. These agencies, 

 combined with wind and decay, remove much of the summer's 

 growth in the autumn. Large areas of bottom growth survive 

 the accidents of the colder season and, together with the de- 

 tached terminal buds, provide for the rapid recovery of the 

 water meadows of Ceratophyllum in the following spring. 

 Though essentially an immersed floating plant, this species has 

 its lower stems fixed in the soft ooze of the bottom upon which 

 they rest, and it thus becomes almost as firmly " rooted " as 

 do the Potamogetons and similar plants. This species consti- 

 tutes the greater mass of the aquatic vegetation of the larger 

 impounding and permanent backwaters. It is known in local 

 parlance as " moss," though this designation is not always con- 

 fined to this plant. No true aquatic mosses have been found 

 in this bottom-land region. This Ceratophyllum forms by far 

 the greater part of the aquatic vegetation in this locality. 



