Polypodium virginianum
Polypodium amorphum
common polypody, polypode de virginie, rock polypody, tripes-de-roches
irregular polypody, irregular polypody fern, Pacific polypody
often whitish pruinose, slender, to 6 mm diam., acrid-tasting;
scales weakly bicolored, lanceolate, contorted distally, base and margins light brown, sometimes with dark central stripe, margins denticulate.
often whitish pruinose, slender, to 6 mm diam., acrid-tasting;
scales weakly bicolored, lanceolate, contorted distally, bases and margins light brown, sometimes with dark central stripe, margins often coarsely dentate.
to 40 cm.
to 30 cm.
slender, to 2 mm diam.
slender, to 1.5 mm diam.
oblong to narrowly lanceolate, pinnatifid, usually widest near middle, occasionally at or near base, to 7 cm wide, somewhat leathery;
rachis sparsely scaly to glabrescent abaxially, glabrous adaxially;
scales lanceolate-ovate, usually more than 6 cells wide.
oblong to rarely deltate, pinnatifid, usually widest near middle, occasionally at or near base, to 4 cm wide, somewhat leathery;
rachis sparsely scaly to glabrescent abaxially, glabrous adaxially;
scales lanceolate-ovate, usually more than 6 cells wide.
oblong, less than 8 mm wide;
margins entire to crenulate;
apex rounded to broadly acute;
midrib glabrous adaxially.
oblong, less than 12 mm wide;
margins entire to crenulate;
apex rounded to broadly acute;
midrib glabrous adaxially.
midway between margin and midrib to nearly marginal, less than 3 mm diam., circular when immature.
midway between margin and midrib to nearly marginal, less than 3 mm diam., circular when immature.
more than 52 µm, tuberculate, surface projections more than 3 µm tall.
more than 58 µm, rugose to verrucose, surface projections less than 3 µm tall.
free.
free.
present, usually less than 40 per sorus, heads covered with glandular hairs.
present, usually less than 40 per sorus, heads covered with glandular hairs.
= 148.
= 74.
Polypodium virginianum
Polypodium amorphum
Traditionally, two cytotypes have been recognized within Polypodium virginianum (I. Manton and M. Shivas 1953). Recent research has demonstrated that the tetraploid cytotype, which properly bears the name P. virginianum (R. Cranfill and D. M. Britton 1983), is an allopolyploid produced by hybridization between the diploid cytotype (here called P. appalachianum) and P. sibiricum (C. H. Haufler and M. D. Windham 1991; C. H. Haufler and Wang Z. R. 1991). Although sometimes similar to its diploid parents in overall leaf morphology, P. virginianum has consistently larger spores, typically more than 52 µm (see additional comments under P. appalachianum and P. sibiricum). Frequent hybridizations between P. virginianum and P. appalachianum form morphologically intermediate, triploid individuals with misshapen spores. Sterile triploids also result from hybridization between P. virginianum and P. sibiricum.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The diploid Polypodium amorphum is one of the progenitors of allotetraploid P. hesperium, and these two species are occasionally sympatric. Although P. amorphum can be mistaken for P. hesperium, consistent differences exist for separating these two species (see comments under P. hesperium). Hybridization between P. amorphum and P. hesperium results in triploid individuals with misshapen spores (F. A. Lang 1971).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Go Botany
IL Wildflowers
MD Biodiversity
MI Flora
MN Wildflowers
MO Plants- Local floras:
BC, 
OR, 
WA - Local Web sites:
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
