98 IOWA ACADEMY OF SCIENCES. 



NOIES ON THE POLLINATION OF SOME LILUCE^ A.ND A FEW 

 OTHER PLANTS. 



BY MARY C. ROLFS. 



It will not he necessary in this connection to refer to the literature. This may 

 be obtained from such works as Herman Mueller and Darcy W. Thompson. In 

 the identification of insects help was obtained from Prof. Osborn and Miss Beach. 

 Erythonium alhidum, Nuttall. Tnis is the earliest of the Liliacece to come in 

 flower, in fact one of the earliest of our spring flowers. Owing to numerous rains 

 last spring it was difficult to study the species, and insect visitors were few. 

 Flowers perfect. Nectar is secreted near the base of the inner divisions of the 

 perianth. Two small beetles were found feedmg near base ot the perianth. Ants 

 were found as incidental visitors often walking over stamens and pistil. 



Visitors— HEMrPTERA—Crtjjs/rfrte, Li/gens pratensis, was also found in the 

 flower. Mr. Charles Robertson reports twenty-two for Carlinville, Illinois. 



Smilacina stellata, Desf. Found growing in low moist places. Flower perfect. 

 Visited during early partot the day by flies feeding upon the pollen. The floweis 

 opening in the early part of the spring, and are visited at first by Diptera almost 

 entirely, but later its visitors were increased. The pistil hasi a three cleft stigma, 

 ripens simultaneously with the stamens. They are of the same length. Insects m 

 seeking the nectar, which is secreted at the base of the corolla, leave some of the . 

 pollen from another flower on the stigma. 



Visitors — Diptera — Muscidae: Mtisca domestica, Scaiophago sqiialidn, 

 Tachinaflavicaudla. Syrphidae: Syrphus fly. Bibionidae: Bibio albipennis 

 Lyretta pipens and Mesoc/rapta marginata (feeding on the pollen), Hymenoptera 

 Apidae: Halictus albipennis, Halictus tegularia, H. zephi/ras. Nomada bisig- 

 nata. Angochlora jmra and Agapostemon radiatus feeding on the nectar. 



Polygonaium biforum, Ell. Grows on shaded hillsides in large patches, peren- 

 nial herb with simple curving stem, from creepmg root stock. Flowers axillary 

 greenish and nodding. Perianth cylindrical oblong, six lobed at summit. The 

 six stamens are inserted on or near the middle of the segments of perianth, with 

 introrse anthers. Style slender, obtuse, slightly three lobed stigma. Flower 

 perfect. The perianth is about half an inch in length and the summit, or top of 

 the tube, is filled by the anthers and pistil, thus warding off" uninvited guests. 

 The insect is guided to the flower by the odor and to the nectar by the slightly 

 yellowish color near the base of the inner segments of the perianth. Insects 

 feeding on the nectar alight on the flower and force their way to it by pushing 

 aside the anthers; in so doing the pollen falls upon the insect, and, when it 

 searches for food on some other plant, it comes in contact with the pistil and 

 leaves some of the pollen. It is mostly visited by large insects, such as the 

 bumble bee. 



