1. The salt marshes of northern Kansas are characterized by large areas absolutely destitute of vegetation; by the paucity of species around their margins; and by the entire absence of all woody plants. 2. The vegetation of the streams flowing through them consists of diatoms and the three sedges, Scirpus pungens Vahl., S. campestris Britton, and S. lacustris L. 3. The three characteristic plants in and about the barren portion are Distichlis maritima Raf., Polygonum ramosissimum Michx., and Suœda diffusa Watson, of which the Suæda is by far the least abundant 4. The plants which may be regarded as successful invaders are the following: Iva ciliata Willd., Sporobolus heterolepis Gray, Sporobolus Texanus Vasey, Atriplex expansa Watson, Aster multiflorus Ait., Ambrosia psilostachya DC., and Hordeum jubatum L. Sporobolus Texanus Vasey has never been reported, I believe, beyond the southern part of Kansas. Its abundance in the northern tier of counties of Kansas extends its northern limit nearly two hundred miles. 5. Among the less successful invaders which are quite common are the following. Panicum Crus-galli L., Panicum virgatum L., Euphorbia marginata Pursh, Euphorbia glyptosperma Engel, Chenopodium hybridum L., Polygonum Persicaria L., Polygonum Hydropiper L., Amarantus chlorostachys Willd., Datura Stramonium L., Solanum rostratum Dunal, Xanthium strumarium L., Helianthus annuus L., Œnothera biennis L., Gaura parviflora Dougl., Elymus Virginicus L., and Spartina cynosuroides Willd.