1902,] NATURAL SCIENCES OF PHILADELPHIA. 



35 



Observatioits on the Flowering of Lobelia cardinalis 

 AND Lobelia syphilitica. 



In my garden during tlie past year, 1900, I had some fifty plants 

 •each of Lobelia syphilitica and Lobelia cardinalis in rows side by 

 side. They were so near each other that some of the flower stems 

 of the latter fell over and seemed to be blooming among the plants 

 of the former. It surprised me one day to note that while numer- 

 ous winged insects visited the blue-flowei'ed species, none cared for 

 the scarlet ones. This excited an interest that led to a continuous 

 observation through the whole flowering period. At no time did I 

 see an insect visitor on the cardinal flower, while every day the 

 blue-flowered species had abimdant attention. On one occasion I 

 found a humming-bird, Trochilus colubris, at work on the cardinal 

 flower, and the zest with which numerous flowers were examined by 

 the bird attested to the presence of nectar, a fact which my owTi 

 test subsequently verified. The bird is not numerous on my ground, 

 and with an abundance of flowers of various kinds over many acres 

 of ground, it may be inferred that it was not a frequent visitor to 

 the cardinal flower. I observed it only on this occasion. It whoUy 

 neglected the blue-flowered species, that seemed so attractive 

 to the insects. Toward the end of the season the foreman in 

 charge, Mr. Hemming, captured specimens of all that were visitors 

 to Lobelia syphilitica during one day. These were identified by 

 Mr. William J. Fox as follows : Xylocopa virginica, Bombus penn- 

 sylvanicus, Bombus fervidus, Bombus americanorum var. pallidus, 

 Apis mellifera, and a sand wasp, Scolia dubia. It is worthy of 

 note that the honey-bee did not visit the flowers till late in the 

 season. About fifty yards away from these plants was a large bed 

 of Sedum spectabile, which at the earlier stage of these observations 

 were crowded by this well-known honey gatherer. It may be 

 inferred that as long as they lasted they collected all needed from 

 these flowers. Honey-bees at any rate are not numerous in this 

 vicinity. 



At the end of the season no difference could be observed in the 

 fertility of the two species. Every capside seemed abundantly seed- 

 bearing. The presence or absence of insect visitors had no effect. 

 Dissecting the flowers from time to time, and in various stages 

 before and after authesis, some original and interesting phenomena 



