98 ANNALS OK THE ,viISSOURI BOTANICAL GARDEN 



[Vol. 2 



have tried to introduce a tree that he knew so well from his 

 childhood and youth in England. 



It is certain that in the course of time man has assisted 

 in introducing many species of plants, some consciously, as, 

 for instance, plants for cultivation, others by chance and 

 unconsciously. 



In the famous Viking ship from Osoberg, which is believed 

 with certainty to have originated in the first half of the ninth 

 century, fruit, seeds, and other remains of plants have been 

 found, and have been determined by J. Holmboe ('06). The 

 following cultivated plants were among them: Avena sativa, 

 Corylus Avellana, Isatis tinctoria, Juglans regia, Lepidium 

 sativum, Linum usitatissimum, Pirus Malus, and Triticum vul- 

 gare. As Isatis tinctoria is found growing apparently wild, 

 in certain places in Norway, there can scarcely be any doubt 

 that it has found its way thither from localities where it had 

 previously been cultivated as a dye-plant. This is probably 

 also the case with Serratula tinctoria in Jaederen, near Stav- 

 anger. The weeds found in the Oseberg ship were as follows : 

 Capsella Bursa-pastoris, Chenopodium album, Galeopsis Tet- 

 rahit, Lamium {purpureumf), Polygonum Convolvulus, Stell- 

 aria media, and Urtica urens. Several of these, it is true, had 

 immigrated earlier, as has been said of Galeopsis Tetrahit; 

 but it shows that as early as the time of the Vikings, there 

 were opportunities of importing foreign weeds. 



In monastery gardens various medicinal, household, and 

 ornamental plants were cultivated, and one is inclined to be- 

 lieve that several of these which now have quite a wide dis- 

 tribution in Norway, e.g., Aquilegia vulgaris, Berberis vul- 



aster 



Sambucus nigra, etc., originally spread with the 



It is still easier to demonstrate a number of species of 

 weeds that have been imported recently, and of which some 

 appear to have a really astonishing power of spreading. J. 

 Holmboe ( '00) has traced the spread of the following weeds 

 from the year when they were first observed in Norway: 

 Alyssum calycinum (1857), Anthem is tinctoria (1772?, 1807), 

 Barbarea vulgaris (1790), Berteroa incana (1826), Bunias 



