THK COMMON PRICKLY SHIELD FERN. 



been considered as varieties, and one at least of them [lobatum) distinguished as a species by various 

 authors. 



1. tonchitidioides : *his is usually considered a3 the young state of the form called lobatum. We arc 

 by no means certain that this view is correct, for no doubt very old roots, as was long ago pointed out 

 to us by Mr. Bennett, have been found producing the lonclutiforui fronds. It would rather seem to be 

 the debilitated and partially developed condition of lobatum, whether caused by age or starvation or 

 any other depressing influence. It is certainly not permanently distinct from labatum, but interchange* 

 able with it, for cultivated plants of Itmchitidwuks may be nurtured into lobatum proper; and lobatum 

 proper may be starved into tonchitidioides. The plant so named is dwarf, simply pinnate, often very 

 much resembling J\ Lonchitis, but less spiny, not imbricated, and with a greater or Ic&s tendency to 

 become lohed. It is a fertile state. 



2. lobatum: this variety, which is the fully dcvoloped condition of the previous one, has narrow 

 Innee-shapcd fronds, one to two feet long, and subbipinnatc, u c tf a few only of the pinnules arc developed ; 

 tho anterior basal one is always distinct, considerably enlarged, and strongly auriclcd ; but the rest are 

 cither decurrent or confluent, and not auriclcd. Between it and the type of the species, which is 

 broader, and in which most of tho pinnules should be distinct and auriclcd, there is to be found every 

 grade of variation ; but yet our experience does not tend to the conclusion that the form called lobatum 

 can bo devclo|ied into actdeatttm by culture, but on tho contrary, that it is a |K?rmanont variety of which 

 various gradations exist* It is a common plant* 



3. mtdityidnm : this Mr. Wollaston describes as having the apex of the frond multifid, and tbo pinme 



occasionally dichotomous- 



4. j/roli/erum: another of Mr, Wollaston's varieties; it produces bulbils in the axils of tho lower 



pin me. 



5. argutum ; this has a broad lanceolate frond, with distinct pinnules as in tho typal plant, and 

 dificrs in the form of the pinnules, which are narrowed and elongated ; they terminate in an acute spiny 

 point, and have long spines to tho marginal teeth. It was given to us by ilr. Lloyd, with the 

 information that it had been gathered in some part of Buckinghamshire. 



The variety obtwum, mentioned in tho Handbook of British Ferns (2 ed„ p, 90) as being cultivated 

 in the Royal Botanic Garden at Kcw, cannot be distinctly traced as a British plant, ami is consequently 

 omitted. It appears from specimens in Sir W. Hooker's, and Mr. Howard's herbaria, to be a North 

 American form of the species; ami it is therefore not improbable that the Kew plant may be of 

 transatlantic origin. 



