Cystopteris tennesseensis
Cystopteris utahensis
Tennessee bladder fern
Utah bladderfern
creeping, not cordlike, internodes short, heavily beset with old petiole bases, hairs absent;
scales usually tan to light brown, lanceolate, radial walls tan to brown, thin, luminae tan.
creeping, not cordlike, internodes short, heavily beset with old petiole bases, hairs absent;
scales lanceolate, ± clathrate, radial walls dark brown, thick, luminae clear.
monomorphic, crowded near stem apex, to 45 cm, nearly all bearing sori.
monomorphic, clustered at stem apex, to 45 cm, nearly all bearing sori.
variable in color but mostly dark brown at base, gradually becoming straw-colored distally, shorter than blade, sparsely scaly at base.
green to straw-colored throughout or darker near base, shorter than blade, base sparsely scaly.
deltate to narrowly deltate, 2-pinnate-pinnatifid, usually widest at or near base, apex short-attenuate;
rachis and costae with occasional unicellular, gland-tipped hairs, with or without bulblets (usually misshapen);
axils of pinnae with infrequent multicellular, gland-tipped hairs.
deltate to narrowly deltate, 2-pinnate-pinnatifid, usually widest at or near base, apex short-attenuate;
rachis and costae with unicellular, gland-tipped hairs, misshapen bulblets present or absent;
axils of pinnae usually with multicellular, gland-tipped hairs.
usually perpendicular to rachis, not curving toward blade apex, margins serrate;
proximal pinnae pinnatifid to pinnate-pinnatifid, ± equilateral, basiscopic pinnules not enlarged, basal basiscopic pinnules sessile to short-stalked, base truncate to obtuse;
distal pinnae ovate to oblong.
typically perpendicular to rachis, not curving toward blade apex, margins serrate;
proximal pinnae pinnatifid to pinnate-pinnatifid, ± equilateral, basiscopic pinnules not enlarged;
basal basiscopic pinnules sessile or short-stalked, base truncate to obtuse, distal pinnae ovate to oblong.
directed into teeth and notches.
directed into teeth and notches.
cup-shaped, apex truncate, with scattered, unicellular, gland-tipped hairs.
cup-shaped, apex truncate, with scattered, unicellular, gland-tipped hairs.
spiny, usually 38–42 µm. 2n = 168.
spiny, usually 39–48 µm. 2n = 168.
Cystopteris tennesseensis
Cystopteris utahensis
Cystopteris tennesseensis, an allotetraploid species, has C. bulbifera and C. protrusa as diploid progenitors. The relative distinctiveness of these diploids suggests that identification of C. tennesseensis individuals should be straightforward. As with other members of Cystopteris, however, a series of features makes reliable recognition of this tetraploid challenging. For some characteristics (occasional unicellular, gland-tipped hairs and bulblets; short-attenuate, narrowly deltate blades), it is intermediate between its parents; for others (very short internodes and crowded leaves; occurrence on rock), it tends toward C. bulbifera. This unequal intermediacy, the multiple origins from genetically different individuals (C. H. Haufler et al. 1990), and the occurrence of sterile backcross triploids with its diploid progenitors in zones of sympatry has blurred the already subtle features distinguishing this allopolyploid. For example, some individuals of C. bulbifera may have very few glandular hairs, and some C. tennesseensis appear to lack glandular hairs entirely (R. F. Blasdell 1963). Further, sterile tetraploid hybrids (called C. × wagneri R. C. Moran) between C. tennesseensis and C. tenuis have been reported (R. C. Moran 1983) and verified through isozyme analyses (C. H. Haufler, unpubl. data). Finally, as discussed above, the recently recognized C. utahensis (C. H. Haufler and M. D. Windham 1991) is extremely similar morphologically to C. tennesseensis.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Cystopteris utahensis is an allopolyploid derived from the diploid species C. bulbifera and C. reevesiana (C. H. Haufler and M. D. Windham 1991). Because C. utahensis shares one parent (C. bulbifera) with C. tennesseensis and because of morphologic similarities between C. reevesiana and C. protrusa (the second diploid parent of C. tennesseensis), populations of C. utahensis were previously considered to have originated by long-distance dispersal from eastern populations of C. tennesseensis. Genetic studies using isozyme markers, however, indicated that C. utahensis was a distinct species and stimulated the discovery of morphologic criteria for distinguishing it from its eastern cousin. When combined with the geographic separation of the two tetraploids, the minor differences in indument features provide a means of circumscribing this genetically distinct species. Potential confusion in identifying C. utahensis arises because sterile triploid hybrids may form when it is sympatric with the more common diploid C. reevesiana.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
IL Wildflowers
KS Wildflowers
MD Biodiversity
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
