327 



NOTES ON YORKSHIRE BRYOPHYTES. 



I. PETALOPHVLLUM RALFSII. 



F. CAVERS, B.Sc, 

 Vorkshire College, Leeds. 



1\ a brief note which appeared in 'The NaturaUsl ' in July igoi 

 Mr, W. Ingham recorded the discovery in Yorkshire of the ex- 

 ceedingly rare liverwort Pefalophyllum Ralfsii {W\\s.) Gottsche, 

 which he found growing on Coatham Marshes, in company with 

 a species of Pallavicinia. The latter is itself a rare and interest- 

 ing liverwort, and will form the subject of a later paper, but 

 whereas the Pallavicinia grows in abundance and forms crowded 

 patches, Petalophyllum occurs very sparingly, an isolated plant 

 being found here and there on carefully teasing out the rosettes 

 of Pallavicinia. Last year Mr. Ingham was kind enough to 

 send me numerous dried specimens of the Pallavicinia , and 

 later supplemented this material by sending a large supply of 

 living plants. .\ few specimens of Petalophyllum were present 

 in this Coatham gathering, and a few more were kindly sent by 

 Mr. W. H. Pearson, who collected this plant in Anglesey, again 

 in company with a species of Pallavicinia [P. hibernica var. 

 Wilsoniana). 



Petalophyllum Ralfsii is probabl}" the rarest of the known 

 species of Hepaticce, having up to the present time been found 

 only in about six localities and invariably in very small quantities. 

 It was first collected in Anglesey (1830) and near Penzance (1842) 

 by John Ralfs, and was first described and figured by Wilson 

 ('English Botany,' PI. 2750, Fig. 16; E.B. Suppl., PI. 2874). 

 It was afterwards recorded from two localities in Ireland: one 

 in Co. Dublin, the other in Co. Kerry. P. Ralfsii has recently 

 been collected by Massalongo'" in Italy, apparently the only 

 hitherto recorded instance of its occurrence outside of the British 

 Islands. In all cases it grows in damp sandy ground near the 

 sea. In 1886 Trabutf described as a new species o( Fossombrouia 

 (F. corbulceformis) an Algerian plant which appears to be in 

 reality a Petalophyllum, allied to if not identical with P. Ralfsii. 

 Two other species have been described from Australia and New 

 Zealand. 



■ Sulla scoperta in Italia del Petalophyllum Ralfsii Gott., Bull, della Soc. 

 bot. ital., 1902, p. 37. 



t Revue br3-olog'ique, 1887, p. 12. 

 i9o_^ September i. 



