1862.] LASTREA DILATATA AND ITS VARIETIES. 339 



LASTREA DILATATA AND ITS VARIETIES* 

 By Thomas Moore, F.L.S. 



With the exception of a few very marked forms, of the nature 

 of sub-species, this freely-distributed British Fern has not until 

 lately been observed to sport into so extended a series of varieties 

 or variations as most of the other common species ; but as the 

 keen eyes of Fern-fanciers peer more closely into its native haunts, 

 it is found that many very curious and interesting forms occur. 

 The normal condition is to have a short caudex, upright or 

 nearly so, and furnished like the stipes with entire lance-shaped 

 pointed scales of a light brown colour, and having a much darker 

 bar up their centre ; to have also fronds of an ovate outline, 

 twice or thrice pinnate, Avith spinoso-mucronate serratures. 

 These features include plants varying very greatly in size, from 

 six or eight inches to five feet or more, the two extremes, which 

 are perhaps permanent, being sometimes looked on as varieties. 

 For the most part, the fronds are from two to four feet high, and 

 of an arching or semi-drooping character. 



Falling under the plant thus indicated as a type, but them- 

 selves of the rank of sub-species, are the following, Avhich gradually 

 pass fi'om the normal ovate to an oblong-lanceolate outline of 

 frond. 



DUMETORUM, a dwaiifisX QYatejvaiiety, found Avell-marked in 

 Westmoreland. 



COLLINA, a medium-sized plant, with narrow-elongate ovate 

 fronds, occurring in a characteristic form both in Westmoreland 

 and Arran. 



ALPiNA, with fronds varying from six inches to two or three 

 feet in height, and from ovate to oblong in outline, and when 

 fresh of a soft succulent herl)aceous texture, so that when dried 

 it becomes very thin, a common form on the Scottish highlands, 

 and passing into the North of England. 



Chanteri^, a tall slender plant, with lance-shaped fronds, 

 broadest upwards, a West of England plant. 



GLANDULOSA, a tall erect robust-habited plant, from the Forest 

 of jDearn, with oblong-lanceolate fronds, the link connecting 

 dilatata withspinulosa. 



* From the ' Gardeners' Clu-onicle.' 



