82 



with glandular hairs had been made up to 192 1. At that time 

 it was referred to 5. arvensis. Recent examination, however, 

 of the series of S. arvensis from the Old World and America at 

 the Academy of Natural Sciences of Philadelphia gave the 

 impression that this plant could not be satisfactorily identified 

 with that species. This is evidently a matter for diagnosis by 

 some student of Sonchus and the observations here noted are 

 merely intended as suggestions that may be helpful in such a 

 study of the plant. 



This season additional glandular material was discovered 

 locally and in one case both types were found growing together. 

 This led to a visit to the locality where it was first collected to 

 discover whether any of the glabrous type might be present with 

 the glandular. A part of this area was freshly ploughed but the 

 plant was found along the roadside — abundantly at places, 

 especially along the sides of the road adjacent to the fields — for 

 a distance of over half a mile, and also in part of the area pre- 

 viously visited (now planted in corn). The area of occupancy 

 in the fields here is apparently not coextensive with that of the 

 roadside. No Sonchus with glabrous heads was found. The 

 glandular heads were so distinct that identification at sight was 

 easy. There were few, if any, plants along the roadside embank- 

 ments, etc., that had not grown to maturity after the roadsides 

 had been mowed and these mostly shoAved glabrous branches of 

 the inflorescence with bracts on the pedicels bearing one to few 

 glandular hairs or none. 



Westward along the highway, about 800 feet from the apparent 

 limit of occurrence of the glandular plant, it was with con- 

 siderable surprise that a large field was noted that was yellow 

 with the bloom of Sonchus. This field, which extends for about 

 800 feet along the highway, is of even greater depth. In a 

 walk around this field among hundreds, and more probably 

 thousands, of blooming Sonchus, none was found that was not of 

 the glabrous type. This grass field was not mowed this season 

 and doubtless this was responsible for the mostly rank vegetative 

 growth as well as for the abundant bloom. In a cornfield ad- 

 joining and along its edge adjacent to the grass field, plants 

 occurred that were especially robust and vigorous owing, probably, 

 to the benefits of cultivation. Several of these latter plants in 

 the cornfield were between 6 and 6^ feet high. (Later in the 

 season some were noted to reach even 7 feet or over.) 



