STRUCTURE OF THE FORMATION 71 



spicuous on account of the plumose stigmas and the much 

 exserted anthers. 



Rumex crispus and R. altissiimis occur sparsely, the one 

 within the wet meadow, the other about its margins. Both 

 species owe their very early start in the spring to their thick- 

 ened perennial roots, as the loose rosettes formed by these 

 plants do not withstand the winter. The numerous, green, 

 inconspicuous, pendulous flowers of these docks are polyg- 

 amo-monoecious and anemophilous ; geitonogamy and xenog- 

 amy accordingly result. The least movement of the plant 

 envelops the flowers with a cloud of pollen. The three valves 

 or wings, which are commonly grain-bearing, enable the 

 achene to float, which explains the distribution of these plants 

 along water ways. If these valves are removed, the achenes 

 sink. The remaining species of the vernal aspect need only 

 brief mention. Juncus tenuis frequents a few places in the 

 wet meadow, as a rather Inconspicuous, grass-like perennial. 

 Oxalis stricta forms an interrupted layer below the tall facies, 

 in parts of the wet meadow and meadow formations. During 

 the fall Oxalis forms small, compact mats, which, in protected 

 situations, pass the winter in good condition. The yellow 

 flowered oxalis is one of the first plants to begin growth in 

 the spring. Trifolium pratense and T. repens are growing 

 in the drier portions of the wet meadow. T. pratense forms 

 open rosettes Avhich, with protection, frequently withstand 

 the hardships of winter. 



ELEMENTS OF THE EARLY ESTIVAL FLORAL ASPECT 



Facies 

 Same as for vernal aspect. 



Principal Species 

 Amorpha canescens. Kuhnistera Candida, 



Ceanothus ovatus.* K. purpurea. 



Coreopsis palmata. Meibomia illino'yisis. 



Erigeron ramosus. 



* Extending Into this aspect from the vernal. 



