1914-15. J BOTANICAL SOCIETY OF EDINBURGH 425 



phyllantha (BricL). It is, however, otherwise barren. Ac- 

 cordingly, I had doubts from the first of its claims to rank 

 as a member of this group. A closer examination of its 

 minuter structures has confirmed m}' resolution to reject it 

 from association with the others. Besides, its only habitat 

 hitherto known, viz. the straw-thatch of the older and 

 smaller cottages, is certainly adverse to such an association. 

 The area of growth — from the English Channel on its 

 eastern side to the Frith of Ta}^ — is also adverse to such 

 a connection. Lastly, the shape of its leaves, sharply 

 lanceolate, militate the most against it as well as the 

 difference in their areolation. The fourth of this series, 

 described in the Annals of Scot. Nat. Hist, for July 1900, 1 

 as well as in one or two other parts of the same magazine, 

 is mainly characterised by the leaf in its upper third being 

 abruptly as well as convexly narrowed to rather less in 

 breadth than a half of the lower or broader part but still 

 showing the pagina on each side of the narrowed nerve 

 which can be traced to within a short distance of the broad 

 round apex. 



The fifth of the series was only discovered in October 

 1914 near Blairmore on the Frith of Clyde. The following 

 is its description : — 



1 ;< ptodontium Rossii (Stirn.). — In rather large lax some- 

 what convex tufts of a deep or bluish green colour above, 

 changing abruptly below to a dirty pale colour ; stems 

 strong upright, simple, or at times dichotomously divided, 

 rarely fastigiately branched above, from an inch to an inch 

 and a half long : leaves clasping stem, rather laxly arranged 

 around it, curled inwardly in upper half or crisped when 

 dry, spreading widely or even recurved (outwards) when 

 wet, ovate oblong, smooth throughout or not papillose, 

 margin plane, serrate in upper half with intermediate lesser 

 serratures (or less pronounced), in lower third serratures 

 much less or nearly vanishing ; nerve strong, latit. near 

 base '07- - 08 mm., smooth throughout, tapering upwards 

 and vanishing rather abruptly about 09 mm. from blunt 

 and rounded apex, which is strongly and equally serrated 

 without any apiculus such as are seen in the other three 

 members of the group; central basal cells large, oblong, 

 1 Ann. Scot. Nat. Hist., 1900, p. 176. 



TRANS. BUT. SOC. EDIN. VOL. XXVI. 30 



