690 



WEED FLORA OF IOWA 





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Fig. 532-A. Prostrate Pigweed {Amaranthus blitoides.) 

 (Photographed by Hart.) 



mulUflorus) , fragrant goldenrod (Solidago odora), and many others 

 occupy the ground. What becomes of the flora when the sod and 

 its flora have borne their own peculiar vegetation ? Comparatively 

 few of the original inhabitants thereof remain as a part of the flora. 

 The weeds most likely to appear here are such as have been partially 

 adjusted to the open conditions. In such places it was not un- 

 common in the early days to find that such weeds as the common 

 Iowa tumble weed (Amaranthus graecizans) , tickle-grass (Panicum 

 capillare), creeping verbena (Verbena bracteosa) , milk spurge or 

 milk purslane (Euphorbia maculata and E. geyeri), evening prim- 

 rose (Oenothera biennis), horseweed (Erigeron canadensis), blue 

 vervain (Verbena striata), persisted for a few years, perhaps with a 

 few other perennial weeds like flowering spurge (Euphorbia corol- 

 lata), Helianthus occidentalis and Desmodium canescens, especially 



