VI. POLYSTICHUM. 96 
that, but connected therewith by a short and slender 
but distinct stalk, which again is joined to the rachis 
at a more obtuse angle than is the case with the pin- 
nules of P. aculeat urn. In the outline of the pinnules, 
as well as in the prominence of the spinulose marginal 
serratures, there is much variation in different plants. 
Scattered on the under surface of the pinnules are fine 
hair-like scales. The midvein of each pinnule branches 
alternately : the veins are again branched, and the an- 
terior venule bears a sorus, and is scarcely continued be- 
yond it ; the other venules extend to the margin, and are 
sometimes simple, sometimes forked. The lobe or auricle 
at the base of the pinnule has a vein through its centre, 
throwing off simple venules, some of which are fertile. 
The son are numerous, often crowded, sometimes con- 
fluent ; and covered by nearly circular indusia, depressed 
in the centre, at which part they are attached to the veins 
thus being peltate. 
The variety subtripi/inatum, is a more highly de- 
veloped state of the species, in which all the lower pin- 
nules (the basal ones in particular) are deeply pinnatifid, 
the segments sometimes becoming almost distinct. Being 
thus somewhat more deeply divided, and at the same time 
usually of larger growth than the ordinary P. angulare ; 
it is a more lax and more elegant plant. It is not un- 
common. 
The variety ungustatum, though sharing the elegant 
character of the species, is perhaps less graceful than it or 
the more divided variety. Its peculiarity resides in the 
very narrow and acute pinnules, which are rather more 
distinctly stalked than hi the common forms of P. angu- 
lare. It is further remarkable in being viviparous hi the 
axils of the lower pinnie. It has been found in the 
neighbourhood of Wimbledon, and is preserved in the 
Royal Botanic Garden at Kew. 
Another proliferous form of this species has been sent 
me from Ireland by Mr. Kinahan under the name of 
viviparum. It is a curious depauperated monstrosity, 
