No. 3 compiases those species, which, althougli well established and 

 possibly spreading in a certain locality, are not able to spread far 

 from that spot. Good examples of this class are found in Rosa 

 micrantha, Onopordon Acanthium and Daphne Mezereum, which occnr 

 in single localities where there are plants, which ai-e doubtless many 

 years old, but Avhich do not spi'ead by their seeds any distance. No. 4 

 is made up of those plants which grow for a short time and then 

 suddenly disappear altogether. Most of these have been introduced 

 with seed, or have escaped from gai-dens; and many of them too hav'e 

 doubtless been introduced from Eui'ope in seed imported as food for 

 caged birds. 



In this list the most interesting plants are Solanum rostratum 

 and Hordeum jvhatum, the former being a Colorado plant, and the 

 latter a North Western, and both far out of their proper range. 

 They are generally to be found in some of the streets of the city 

 every year ; but never regularly nor in the same place every year. 



1. AGGRESSIVE WEEDS. PUmfarjo major, L. 



Ranunculus acris, L. Verbascum Thapsus, L. 



Sisymbrium officinale. Scop. Tinaria vulgaris, Miller. 



Brassica Sinapistruui, Boiss. 

 Capsella Bux\sa-pastoris, Mcench, 

 Stellariti media, Smith. 

 Silene noctiflora, L. 

 Cerastium viscosum, L. 

 " vulgatum, L. 

 Portulaca ohracea, L. 

 Hypericum perforatum, L. 

 Malva rotundifolia, L. 

 Trifolium pratense, L. 



" repens, L. 

 Medicago lujiulina, L. 

 Anthemis Cotula, D. C 

 Achilkea viillefolbim, L. 

 Lencanthenium vulgare, Lam. 

 Gnaphalium tdiginosum, L. 

 Cirsium arvense. Scop. 



" lanceolatum. Scop. 

 Lappa officinalis. All. 

 Cichorium Intybus, L. 

 Taraxacum Dens-Leonis, Desf. 

 Sonchus (jJeraceus, L. 



" asper, Vill. 

 c 



Nepeta Cataria, L. 

 Calaniintha Clinopodium, Beath. 

 Galeopsis Tetrahit, L. 

 Leonurus Cardiaca, L. 

 Lithospermum officinale, L. 

 Echinospermum Lappula, Lehm. 

 Cynoglossum officinale, L. 

 Solanum nigrum, L. 

 Chenopodium album, L. 



" hybridum, L. 



Amarantus retrofiexus, L. 



" albus, L. 



Polygonum aviculare, L. 

 " Persicaria, L, 



" Convolvulus, L. 



^ " Ilijdropiper, L^ 



Bumex Acetosella, L. 



" crispus, L. 

 Cannabis sativa, L. 

 Poa compressa, L. 



" jyratensis, L. 

 Pestuca ovina, L. 

 Triticum repens, L. . 



