266 PR0CEEDIXG8 OF THE ACADEMY OF [1890. 



CONTRIBUTIONS TO THE LIFE-HISTORIES OF PLANTS. NO. V. 

 BY THOMAS MEEHAN. 



On THE Anthers of Lappa major. 



I have placed on record that the column of anthers of many com- 

 posites, maturing before the style has finished its growth, is drawn 

 up out of the floret until re.sistance is weak enough to allow the 

 stigmas to escape from the staminal tube. As in almost every be- 

 havior of plants, there are extremes here as well. In some species 

 the style easily escapes from the staminal tube, and the stamens are 

 drawn but little, if any, above the mouth of the floret ; in others the 

 stamens are drawn to a considerable length before, they are drawn 

 back to their normal position, by the elasticity of the filaments. In 

 Lappa the other extreme is reached. The tube is drawn so far be- 

 yond the floret, that the caudate bases of the anthers are past the 

 mouth of the corolla, and cannot get back again. The staminal 

 tube, therefore, presents a condition unusual in composite flowers. 

 The Pollination of Crucianella stylosa. 



In the Proceedings of the Academy of Natural Sciences, 1887, p. 

 325, I noted that the elongating styles of Cephalanthus occiden- 

 talis forced the clavate stigma through the four anthers, clearing 

 out almost completely the pollen from the anther sacs and carrying 

 up the densely pollen-covered stigma to its ultimate full growth, en- 

 suring the most perfect self-fertilization. I also showed that the 

 elongation of the style and full growth of the pistil were very rapid, 

 commencing about 8 P. M. and reaching their full length in al)out 

 half an hour. 



Observing the pa.st summer that another Rubiaceous plant, allied 

 to Galium or Asperula, Crucianella stylosa, Trin., a native of Per- 

 sia but growing in my garden, had long exserted .styles, similar to 

 Cephalanthus, I was moved to cut some branches and place them in 

 water for study as in the former case. 



AVe have here five stamens, instead of four, and the large stigma 

 is forced through the center, just as in the manner described in Ceph- 

 alanthus, evidently pushing up against the closed 5-parted limb of 

 the corolla, which then expands, the style with the pollen-covered 

 stigma continuing to its full growth. As in the case of the Cepha- 

 lanthus, the jwllen is so nearly cleaned out of the anthers by the up- 



