Polypodium virginianum
Polypodium saximontanum
common polypody, polypode de virginie, rock polypody, tripes-de-roches
Rocky Mountain 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 25 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 linear, pinnatifid, usually widest near middle, 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, tuberculate, surface projections more 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 with a few glandular hairs or rarely without glands.
= 148.
= 148.
Polypodium virginianum
Polypodium saximontanum
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.)
Polypodium saximontanum is an allotetraploid species whose progenitor diploid species are P. amorphum and P. sibiricum (M. D. Windham 1993). Prior to its recognition as a distinct species, collections of P. saximontanum were variously referred to P. montense F. A. Lang (= P. amorphum), P. hesperium, and/or P. virginianum. In addition to its separate geographic range, P. saximontanum can be distinguished from P. virginianum by having narrower leaves and a reduced frequency of glandular hairs on its sporangiasters. Polypodium saximontanum also has a separate range from P. amorphum and has spores with large (greater than 3 µm tall) projections. Although P. saximontanum overlaps in range with P. hesperium, the latter species has no sporangiasters. Tetraploid hybrids of these two species have misshapen spores.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Go Botany
IL Wildflowers
MD Biodiversity
MI Flora
MN Wildflowers
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
