Moss : Changes in the Halifax Flora. 



Again, some of the rare moorland plants, which inhabit the 

 drier places, have withstood the smoke, and the firing- of the 

 moors. Of these the most noticeable are: — '43 Trientalis 

 Europcea,' '79 Rubus chamcemorus / and ' 132 Genista anglica.' 



It is significant that practically all the rarities mentioned by 

 Bolton, which survive at all, survive in the identical stations 

 mentioned by him. This fixity of station is a fact which goes 

 dead against Lees' interpretation of the natural changes which 

 species undergo in a given area. The following plants men- 

 tioned by Bolton are still in the exact localities named by him: — 



'25 Campanula hederacea,' 1 '41 Narthecium ossifragum,' '42 

 Crocus nudiflorus,'' '43 Trientalis Europcea,' '55 Pyrola minor,'' 

 * 56 Andromeda polifolia,'' 1 79 Rubus chamcemorus, I ' 93 Trollius 

 Europceus / ' 107 Thymus serpyllum, ' ' 132 Genista anglica,'' ' 166 

 Viola lutea ' and 181 Salix repens. 



V. This class includes plants belonging to the type usually 

 recorded by Qolton, but actually not mentioned in his list, 

 because, I think, he overlooked them. The following are the 

 chief : — 



Vicia sylvatica, 1820;* Arctostaphylos Uva-ursi, 1666; Ver- 

 €7iica scutellata, 1832 ; Neottia Nidus-Avis, 1878 ; Habenaria 

 chloroleuca, 1838; Tamns communis, 1831 ; Geranium sylvaticum, 

 1892 ; and Epilobium roseum, 1895. 



VI. This is perhaps the most remarkable class of all, 

 including plants which have in all probability appeared since 

 Bolton's time. They are practically all aquatics, and their 

 recent introduction is due to the making of canals and the 

 increase of suburban mill-dams. Perhaps some of them existed 

 in the Calder before the making of the various parts of the 

 canal (1758, 1794, 1825), as the river would then be com- 

 paratively unpolluted by sewage and mill-refuse ; but a river 

 like the Calder, with a strong current and liable to spates and 

 floods, probably never provided a home for floating types like 

 Sagittaria and Potamogeton eu-natans, and submerged species like 

 Zannichellia and Potamogeton pusill us \ though river-side plants 

 such as Glyceria aquatica and Epilobium hirsutum no doubt 

 occurred. The following are the chief of this class : — Nasturtium 

 amphibium R.Br., Lysimachia vulgaris L., Polygonum amphibium 

 L. , Ceratophyllum demersu?n L., Elodea canadensis Michx., Typha 

 1 at i folia L. , Sparganium ramosum Huds., S. simplex Huds., 

 Acorus Calamus L. , Lemna trisulca L. , L. minor L., Sagittaria 



* I give the date of the first Halifax record. 



Naturalist, 



