1 82 The Irish Naturalist. [July, 



SCROPHUIvARIA UMBROSA (DUM.) IN IRELAND. 



BY NATHANIEL COLGAN, M.R.I. A. 



As this somewhat critical species has not hitherto been 

 ascertained to occur in Ireland, the Flora of Ulster records for 

 Antrim having been rejected by the authors both of the 

 Cybele Hibernica and of the Flo7'a of North-east Ireland, 

 its discovery in the county Dublin will be of interest to Irish 

 botanists. In August, 1894, I met with a few plants growing 

 by the side of the Liffey in lyUcan demesne, and on making 

 further search in the September of last year, lower down the 

 river, between Knockmaroon and Woodlands, it was found 

 again, and in considerable quantity, on both the right and left 

 banks, associated with its congeners, S. aquatica and 6*. 7iodosa. 

 My suspicions as to the identitj^ of the lyiffey plant with 

 S- zimdrosa ('Dnm.)=^S. Ehrharti (Stev.) have been confirmed 

 by Mr. Arthur Bennett, the Rev. B. S. Marshall, and the Rev. 

 W. Moyle Rogers, who have kindly examined specimens. The 

 occurrence of the three speciesin association on the Liffey banks 

 makes it easy to observe in the field the marked differences 

 which separate them. Intermediate in many points between 

 S. aquatica and 6*. nodosa, S. unibrosa is yet separable at a 

 glance from either by the peculiar form of its inflorescence. 

 The rigid branches of the lax and widely-spreading cyme are 

 almost filiform in their slenderness. By an error, which has 

 no doubt caused much confusion amongst British botanists, the 

 terms descriptive of the C5anes of ►S. umbrosa and S- aquatica 

 have been transposed in the 3rd Edition of Hooker's Stiidcnt's 

 Flora, those of the first being set down as contracted and of the 

 second as lax. Further search along the Irish rivers may be 

 expected to extend to other districts, the range of this in- 

 teresting plant, which seems fully entitled to take specific 

 rank. 



