FLORULA OF A PIECE OF WASTE GROUND AT ABERDEEN 29 



With them, as weeds, were probably introduced from Continental 

 Europe such grasses as Apera Spica-venti, Beauv., Avena sfn'gosa, 

 Schreb., A. fatua, L., Festuca uniglumis, Sol., Bromus inadri- 

 tensi's, L., sEgilops triuncialis, L., and sE. candata, L., all of 

 which were found in 1893 or 1894, but either did not appear 

 in a second season or became scarcer year by year. 



Glyceria distans, L., and Hordeum maritimum, With., which were 

 both locally common in 1893, were much less common in 

 1894, and were not found after that year. G. distans is not 

 common in this part of Scotland. It had probably been 

 introduced among refuse from grass seed. H. inaritiinuui 

 more likely owed its presence here to its occasional use as an 

 ornamental grass. 



Lolium perenne, L. The Rye Grass was abundant in 1893, becoming 

 relatively less abundant in 1894 and 1895, an d a little more 

 common again in 1896. In 1893, and even more markedly 

 in 1894, it showed a very great diversity in its development, 

 largely due to differences in the soil. On the beaten tracks and 

 harder spots the plants were often very stunted, with slender in- 

 florescences and distant small spikelets ; but where the soil 

 was rich in organic food many of the plants grew to a great 

 size, and bore very large inflorescences, many of which bore 

 numerous branches. The branched forms often showed a 

 tendency to bear small abortive spikelets. Occasionally a stern 

 bore an inflorescence of the usual form on a branch from a 

 node near the base, and ended in a large branched inflorescence 

 on the main stem. 



A comparison of the lists for the several years will show 

 the general course of change that the vegetation underwent 

 from year to year ; but a very brief summary will not be 

 out of place here. A large number of the adventitious 

 species that appeared in 1893 did not survive the following 

 winter, or reappeared in 1894 only in much diminished 

 numbers. Others, like the vine, have lingered on in lessen- 

 ing numbers till 1896 ; others, like celery, have just held 

 their place ; and others, such as Sisyinbrium pannonicum, 

 Medicago sativa, M. falcata, and Melilotus officinalis, have 

 increased considerably. A few, e.g. Melilotus alba, became 

 more common for a time, and then appeared to die out. It 

 is curious to note that some of our most common weeds of 

 cultivated soil never seemed to gain a hold, even when they 

 formed a part of the vegetation in 1893. Fumaria officinalis, 



