TORREYA 



LIBRAI^T 

 HHW YORK 



BOTANICAL 



Vol. 23 No. 5 



September October, 1923 



ADDITIONAL NOTES ON SONCHUS ULIGINOSUS 



Harold W. Pretz 



The distribution of Sonchus uliginosus in the Philadelphia 

 region has been well recorded by Mr. Bayard Long in a recent 

 contribution* but during the past season additional collections 

 and observations relating especially to its economic status and 

 identity have been made that seem worthy of note. Since it 

 was first collected in 191 7 it has not only been found in many 

 new localities but it has been observed appearing in areas 

 familiar through field work. This season of 1922 collections 

 have been made from eight new areas (not before reported) and 

 there still remain to be visited other Sonchus stations observed 

 while enroute on passing trolley cars. Though in some stations 

 it has been observed to persist for years and apparently spread 

 during this time, often in spite of cultivation, it is yet too early 

 to very definitely note its spread in the region, or even in specified 

 local areas. 



It has already been notedf that the Sonchus spreads by long 

 horizontal roots and some opportunity was had to note some- 

 thing of its behavior in this respect. On July 23 the under- 

 ground parts of the Sonchus were examined in a. fallow field 

 where corn had been growing the season before. It was dif- 

 ficult to follow roots in the stiff soil with a botanical trowel but 

 one root was followed for slightly over thirty inches from a 

 rosette, after which a much thinner root was followed about 

 five inches, when it was lost in digging. This root was about 

 two to four inches from the surface and was unbranched. In 



* Sonchus uliginosus occurring in the Philadelphia Area, Bayard Long, 

 Torreya, Vol. 22, No. 6, p. 91. 

 Ci\ t New records and other notes on North Dakota plants, O. A. Stevens, 



^ Torrey Bulletin, Vol. 49, No. 4, p. 102. 



79 



