196 MR. J. "WI2^DS0R ON THLASPI ALPESTRE. 



Observations on triilasjpi al^pestre (L.). 



By JoHK WiNDsfe, F.L.S., F.E.E.S,, &c. 



[Kead November 21, 1867.] 



TjSZaspi althstee is a plant which, as the late Sir J. E. Smith 

 has well remarked in 'English Botany,' p. 81, 1st ed., has not 

 always been well understood by botanists ; and, even at the pre- 

 sent day, doubts may be entertained whether its different forms, 

 varieties, or subspecies, as occurring in Britain, have been fully 

 established. 



I have on various occasions collected and compared the Mat- 

 lock and the Settle or Malham plants (the latter again on June 

 22, 1867), and am induced to regard them as different forms, 

 or rather subspecies, of Thlaspi alpestre. Smith, in ' English 

 Botany,' also in his 'Flora Britannica,' p. 686, and in his ' Eng- 

 lish Elora,' vol. iii. p. 172, describes one form only. 



In Babington's * Manual of British Botany,' three forms are 

 described ; and I observe that in the last or 6th edit, he conti- 

 nues to give just the same description of them as before, viz. : 



1. Thlaspi alpestre, having the style equalling or exceeding 

 the notch^ and the pouch presenting an oblong- obovate form. 



2. Var. T. occitanum (Jordan), having its pouch of a triangular- 

 obcordate form, from its lobes somewhat diverging — the style 

 much projecting, and the leaves being often slightly dentate. 



3. Thlaspi virens (Jordan), having an obovate pouch with a 

 broad shallow notch, and a much-projecting style. I may note 

 here that I have found the style in each form of about equal 

 length, but they are often absent or fallen off. 



With regard to the first form, named alpestre, I have not 

 collected It In the stations assigned to it ; but judging by 

 two specimens I possess from Teesdale, and comparing them 

 with the Matlock plant, I can discover no decided differences, 

 except that the former seems a little taller. They both appear 

 glaucous in colour ; but this character is not so apparent in dried 

 plants as in recent ones; the pouches appear to be of the same 

 form, and the styles about equally projecting. 



AVith regard to the next two forms, I consider that they pre- 

 sent differences entitling them to be considered distinct, or va- 

 rieties or subspecies. The figure 81 in * English Botany,' 1st 

 edit,, Is a very good representation of the Matlock plant, as to its 

 general aspect and glaucous hue ; but the pouch, as afterwards 



