I. FOLYTODIVM. 53 
well-drained porous loamy soil ; and may be increased by 
dividing the tufted caudex. 
4. Folypodium Dryopteris, Linncetis. Smooth 
three-branched Polypody, or Oak fern. Fronds ternate, 
glabrous, membranaceous, branches pinnate; pinnaj pin- 
natifid, with obtuse subcrenate lobe?. 
POLTTODIFM DRYOPTERIS, Linnasus: Enpr. Bot. 616: Sm. En?- 
FLiv. 269: Hook and Am. B. FL 567 : Bab. Man. 409: FloriR 
Brit iv. 42: Newm. 123: Franc. 24. LASTREA DKTOPTXKIS, 
Newm. POLYSTICHCM DRTOPTEKIS, Roth. GYMSOCAKPIUM DBT- 
OPTEBW, Newm. App. xxlv. PHEGOPTEBIS D&TOPTERIS, Fee. 
[Pclj-podiora Dryopteris.] 
The Smooth three-branched Polypody has a dark- 
coloured, widely creeping slender caudex, often forming a 
