EVENING PRIMROSE FAMILY 



ONAGRACEAE 



GAURA 



Gaiira biennis L. 



This Gaura is the only species in Illinois. It is a biennial 

 herb which grows in rather dry soil from Quebec to Ontario and 

 Minnesota, south to Georgia and Arkansas, and blooms from 



July to September. 



The first year it produces a 

 rosette of leaves which manufacture 

 food to be stored in the roots and 

 used the following year. The second 

 year it sends up an erect, much 

 branched stem 2-5 feet high, covered 

 with short downy hairs and bearing 

 alternate sessile leaves. 



The rather loose spikes are pro-' 

 duced at the ends of branches as well 

 as at the terminus of the main stem. 

 The flower parts are attached above 

 the ovary. The slender calyx tube is 

 prolonged beyond the ovary and at 

 the summit is divided into 4 rather 

 long, narrow and reflexed lobes. 

 The 4 slightly unequal petals are 

 white, becoming pink with age. 

 Petals and the 8 stamens are in- 

 serted on the throat of the cal\TC 

 tube. Stamens and the slender style 

 are at first turned down. The sta- 

 mens straighten as the anthers ma- 

 ture, and after the pollen has been 

 discharged or nearly so the style 

 straightens and the 4-lobed stigma, 

 closed and surrounded by a cuplike 

 ring, opens. The 4-ribbed nutlike 



fruit is acute at both ends, less than one-quarter inch long, 



covered with soft hairs and contains 1-4 seeds. 



Because the flowers are quite small and not a vivid color, the 



name Gaura, which comes trom a Greek word meaning superb, 



seems not to characterize our species very well. 



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