78 STUDIES IN THE VEGETATION OF THE STATE 



and hence the greater prominence it derives. Its period of 

 an thesis lasts about sixty days, during which time its numer-. 

 ous purple flowers give a characteristic coloring to the 

 patches. The flowers are heterodistylous and accordingly 

 xenogamous ; the insect, in securing nectar from the base of 

 the calyx tube, carries the pollen from the long stamens to 

 the long pistil, etc. Steironema ciliatum occurs in draws 

 with Lythrum alatum and at one or two stations in the 

 meadows. It is a rootstalk plant, by means of which it forms 

 rather definite patches. Steironema is not abundant enough 

 to be of importance. Teucrium occidentale and T. canadense 

 are inhabitants of low meadows and draws, in which situa- 

 tions their individuals become aggregated. T. occidentale is 

 also sparsely scattered through the sedge meadow formation. 

 The two species frequently grow in the same patch, the type 

 specimens of each, however, being recognized at a glance. 

 Neither species is abundant enough to add materially to the 

 formation or the aspect. 



Habenaria Icucopliaea, Thalictrum purpurascens, and 

 Lilium canadense are frequenters of low meadows and ravines 

 where they occur sparsely. The showy spikes of white frag- 

 rant flowers of Hahenaria are conspicuous objects in the 

 vegetation, though never abundant enough to give color to 

 the aspect. Xenogamy or geitonogamy results from insect 

 pollination. The nectar is secreted in large quantities in the 

 very elongated spur of the lip. The insect, in order to reach 

 the nectar, (of necessity an insect with a long proboscis) 

 brings his head or proboscis in contact with a viscid disc, 

 to which are attached the two pairs of pollinia. These pol- 

 linia adhering to the head parts are thus torn away from the 

 flower and stand a good chance of coming in contact with 

 the broad stigmatic surfaces of the succeeding flowers, to 

 which they readily adhere if the stigmas are receptive, i. e., 

 covered with very adhesive viscin. The above is practically 

 what obtained when these flowers were exposed to "night 

 flyers." On account of the resemblance to the facies, the 



