172 ILLINOIS STATE ACADEMY OF SCIENCE 



Arts," publislied what he called "A Catalogue of the 

 Plants of Illinois." In this list he mentions 8 plants 

 which are now "usually regarded as weeds. These are: 

 Cerastium vulgatum, Polygonum Convolvulus, Verhas- 

 cum Thapsus, Mollugo verticillata, Solanum carolinense, 

 Oenothera hiennis, Polygonum aviculare and Veronica 

 peregrin a. The first 3 are known to have been intro- 

 duced into America from Europe. At least 2 of the re- 

 maining 5, Solanum carolinense and Mollugo verticillata, 

 have probably migrated into Illinois either from the 

 West or from the South. Two more, Polygonum avi- 

 culare and Veronica peregrina, are known to be cosmo- 

 polites. The one remaining species, Oenothera hiennis, 

 evidently belongs in that category of plants which assert 

 themselves as weeds under the cultural conditions 

 brought about by man. 



The following 11 immigrants, not before mentioned, 

 were found in 1852, either ' '■ in limited quantities " or ' * as 

 single specimens," as recorded by Brendel; those found 

 in limited quantities were Dactylis glomerata, Digitaria 

 humifusa, Rumex ohtusifolius, Trifolium pratense and 

 Veronica arvensis. Two of these, Rumex ohtusifolius 

 and Digitaria humifusa, may become pronounced weeds. 

 The others are inserted as members of an introduced 

 flora. The remaining 6 were found as single specimens 

 by Brendel in the vicinity of Peoria. They are reported 

 by him as occurring in great abundance eighteen years 

 later (1870). They are Linaria vulgaris, Rumex Aceto- 

 sella, Sonchus asper, Cynoglossum officinale, Lappula 

 echinata, and Leonurus cardiaca. 



By 1859, many additional introduced species had been 

 noted by various collectors. The majority of these were 

 reported by Lapham in 1857, but several represent spe- 

 cies added by Vasey and Brendel during the two follow- 

 ing years. Lapham 's catalogue of Illinois plants ap- 

 peared in the Transactions of the Illinois State Agricul- 

 tural Society. In making up the list, he states that he 

 examined extensive collections of plants exhibited at the 

 state fair held at Chicago in 1855. He also had the 

 benefit of information furnished by various collectors of 

 that period, among whom was Dr. S. B. Mead, of Han- 



