THE POLYSTICHUMS 189 
habitats, since it extends far north into the Scottish glens, where 
P. angulare, its more delicate relative, exists but as a rare record. 
P. aculeatum is very widely distributed, and frequents hedgebanks, 
woods, and in the north and elsewhere is found in abundance in 
the rocky walls of deeply cut streams, where its handsome plumes 
of fronds may be a yard long in favoured spots. It is by no means 
a dainty Fern, and its culture is of the easiest. Like its relatives 
it is a thorough evergreen, and its bright, lucent fronds, see Plate, 
do not drop, unless by stress of weather, until the new set rises in 
the spring to take their place. In habit it is more erect than А 
angulare, and Из most persistent differentiating character is that 
in P. angulare the minor subdivisions have a distinct stalk, but in 
P. aculeatum they are wedge-shaped, and the attachment is by the 
point of the wedge, no stalk appearing. It forms a very stout caudex 
and carries its fronds in a circle, so that a well-grown pot plant is 
very handsome. 
This species has yielded a fair number of varieties, some, аз we 
shall see, of peculiar interest. 
ACROCLADON (Fig. 214).—Found by Mrs. Thompson near Exeter ; 
as our illustration shows, it has a very beautifully branched and 
heavy terminal crest, Ше pinnae being reduced in size and tasselled 
on regular, but smaller lines ; it is of rigid, erect habit and very 
ornamental. 
ACULEATO-CRUCIATUM (HYBRIDUM) (Lowe).—A narrow cruciate 
form, interesting as being, we believe, the first intentional hybrid 
between two recognized species, viz. P. aculeatum densum X 
P. angulare Wakeleyanum, a cruciate variety, 1.6, with most of the 
pinne in duplicate, and set оп at obtuse angles to each other, thus 
forming crosses with the opposite pairs. Mr. E. J. Lowe effected 
the crossing. At first the hybrid was thought to be barren, bearing 
only aborted spores, but eventually numbers were raised showing 
the combined characters and resembling the immediate parent. 
ACUTILOBUM.— Found by Mr. Allchin ; subdivisions narrow and 
acute, resembling the proliferous forms of P. angulare, and like those, 
proliferous ; lax habit. 
CAPITATUM.—Heavy terminal crest. 
CORYMBIFERUM.— Heavy bunch crest. 
CRISTATO-GRACILE.—Found by Mr. Bolton; very spiny, small- 
tasselled. 
Dexsum.—Very foliose, pinnz imbricate ; found by Mr. Jackson. 
GRANDICEPS ABBOTTE.—Found by Mrs. Abbott; a splendid 
form, somewhat on the lines of acrocladon. 
PuLCHERRIMUM.—Found by a farm labourer in Dorset, and given 



