T POLYPODIUM. 55 
This species is almost entirely confined to wild and 
mountainous rocky districts, occurring in the drier parts of 
wet woods, and in the neighbourhood of waterfalls, sometimes 
growing on limestone in company with P. Robertianum. 
It is met with in- various parts of England, Wales, and 
Scotland, but is very rare hi Ireland. It occurs also 
throughout Europe, Northern Asia, and North America. 
This species is a moisture-loving plant, and also a lover 
of shade and shelter ; indeed its delicate texture would 
render it liable to injury if much exposed. It is, however, 
an excellent dwarf rock fern, and very hardy. It is a 
very free-growing pot plant, and may be readily increased 
by the division of its creeping caudex. 
5. Polypodiuxu Robertianum, Hoffman. Lime- 
stone Polypody. Fronds subternate, glandular-mealy, 
lower branches bipinnate at the base; pinna? pinnatitid 
with obtuse lobes. 
POLTPODIUM ROBEBTIANTTM, Hoffmann. P. CALCAREUM, Smith, 
Fl. Brit. 1117: Eng. Fl. iv. 270: Eng. Bot. 1525: Hook and Arn. 
Fl. 567 : Bab. Man. 409 : Florig. Brit. iv. 43 : Nowm. 131 : 
Franc. 24. LASTBEA ROBERTIANA, Newman. L. CALCAHKA, 
Newm. GTMNOCABPICM ROBEKTIANUM, Newm. App. xxiv. PHE- 
GOPTEBIS CALCAREA, Fee. 
The Limestone Polypody has a dark brown creeping cau- 
dex, rather stouter than that of P. Dryopteris. The fronds 
grow up in May, and attain full development soon after 
Midsummer. They are deep dull green, firm and sub- 
rigid in texture, six to twelve or eighteen inches in height, 
erect, and without the marked deflexure of the rachis ob- 
servable in P. Dryopteris. In vernation their pumas are 
rolled up separately into little balls. The stipes is stoutish, 
pale-coloured, much longer than the frond, abundantly 
scaly about the base, and clothed with very minute stalked 
glands which occur more or less over the whole frond, 
giving it a dull mealy aspect, which character forms an 
