THE FLORA OF LONDON BUILDING-SITES 123 



Wind-distributed Plants. 

 Epilobium angustifolium Ij. 1, Taraxacic7n officinale Weher. 1, 



2, 3, 4. 3. 



E. roseum Schreb. 1, 4. Sonchus oleraceus L. 2. 



Tussilago Farfara L. 1, 2, 3, 4. Salix (species?). 

 Senecio vulgaris L. 2, 4. Popuhcs nigra L. 



Small-seeded Plants. 

 Capsella Bursa-pastoris Medi- Cerastium vulgattim L. 3. 

 kus. 1, 2. Polygonum avictilare L. 2. 



Stellaria media Villars. 1, 2. 



Forage or Packing Plants. 

 Trifolium repens L. 1, 2. Agrostis alba L. 2, 3, 4. 



Sambucus nigra L. i4i;e?ia sativa L. (cultivated 



Achillea Millefolium L. form). 1, 2, 3. 



Plantago media L. Poa annua L. 1, 2, 4. 



P. major L. 1, 2, 3, 4. Pteris aquilina L. 1, 3. 



Atr iplex patula Ij. 1,2. 

 Polygonum Convolvulus L. 1, 

 2, 4. 



Cultivated Plants. 

 Brassica oleracea L. (cultivated Baphanus sativus L. (cultivated 

 form). form). 1, 2. 



Oxalis Acetosella L. 

 This last, though a common English plant, was most likely 

 introduced from a cultivated specimen. 



Concluding Eemarks. 



A notable feature in the above lists is that the wind-distributed 

 plants are well represented upon each site, and that most of the 

 plants were found upon all, or at least upon several, of the sites. 

 The efficiency of the wind-distributing organs for scattering seeds 

 in towns is thus clearly demonstrated. 



A visit to the well-known Aldwych site during July afforded 

 an interesting demonstration of the distributing power possessed 

 by these seeds. Clouds of seeds, probably mainly those of Epi- 

 lobium angustifolium, could be seen floating in every direction, 

 and could be traced in one direction as far as Bloomsbury without 

 difficulty. There they were reinforced by seeds from the Blooms- 

 bury site. It is, indeed, possible that the Aldwych site may have 

 been a distributing centre from which all the sites dealt with in 

 this paper have received wind-distributed plants. These plants 

 were, however, probably first introduced into London by other 

 means. E. angustifolium is frequent in villa gardens, and when 

 introduced into one villa garden in a district it rapidly spreads 

 into other villa gardens for a considerable distance. Dr. Henry 

 Laver, of Colchester, called my attention to his stable pit, in 

 which many seedlings of this plant could be seen ; he ascribed 

 their presence to the forage upon which his horses had been fed 



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