Cystopteris laurentiana

(Weatherby) Blasdell

Mem. Torrey Bot. Club 21(4): 51. 1963.

Common names: Laurentian bladder fern cystoptère laurentienne
Endemic
Basionym: Cystopteris fragilis var. laurentiana Weatherby Rhodora 28: 129. 1926
Treatment appears in FNA Volume 2.

Stems creeping, not cordlike, internodes very short, less than 5 mm, heavily beset with old petiole bases, hairs absent; scales uniformly brown to ± clathrate, radial walls brown, luminae clear. Leaves monomorphic, clustered at stem apex, to 45 cm, nearly all bearing sori. Petiole usually dark at base, grading to straw-colored distally, shorter than blade, sparsely scaly at base. Blade ovate to narrowly ovate, 2-pinnate to 2-pinnate-pinnatifid, widest above base, apex short-attenuate; rachis and costae usually sparsely invested with unicellular, gland-tipped hairs, occasionally with misshapen bulblets; axils of pinnae with occasional multicellular, gland-tipped hairs. Pinnae typically perpendicular to rachis, not curving toward blade apex, margins serrate; proximal pinnae pinnate-pinnatifid to pinnatifid, ± equilateral, basiscopic pinnules not enlarged, basal basiscopic pinnules sessile to short-stalked, base truncate to obtuse; distal pinnae ovate to oblong. Veins directed into teeth and notches. Indusia cupshaped, apex truncate, typically sparsely invested with unicellular, gland-tipped hairs. Spores spiny, usually 49–60 µm. 2n = 252.


Phenology: Sporulating summer–fall.
Habitat: Cracks and ledges on cliffs, often on calcareous substrates
Elevation: 0–1000 m

Distribution

V2 397-distribution-map.gif

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que., Conn., Ill., Iowa, Mass., Mich., Minn., Pa., Vt., Wis.

Discussion

Cystopteris laurentiana is a sexual allohexaploid species with C. bulbifera as the diploid parent and C. fragilis as the tetraploid. Cystopteris laurentiana was previously thought to be common only in the Great Lakes region (R. F. Blasdell 1963); it is now known to occur frequently in the Driftless Area of the Midwest. Because C. laurentiana can be difficult to distinguish from C. fragilis, specimens with ovate leaves having unusually large spores and growing on moist cliffs should be checked carefully for occasional glandular hairs, the distinguishing feature of C. laurentiana. Sterile pentaploid hybrids between C. laurentiana and C. fragilis have been discovered where the two species are sympatric.

Selected References

None.

Lower Taxa

None.
... more about "Cystopteris laurentiana"
Christopher H. Haufler +, Robbin C. Moran +  and Michael D. Windham +
(Weatherby) Blasdell +
persisting +
truncate +  and obtuse +
Cystopteris fragilis var. laurentiana +
simple to commonly +
ovate;narrowly ovate 2-pinnate +
reduced +
roundish +
Laurentian bladder fern +  and cystoptère laurentienne +
ovate +  and oblong +
N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, Que. +, Conn. +, Ill. +, Iowa +, Mass. +, Mich. +, Minn. +, Pa. +, Vt. +  and Wis. +
0–1000 m +
often +  and glabrous +
Cracks and ledges on cliffs, often on calcareous substrates +
gland-tipped +, unicellular +  and multicellular +
of uniseriate , multicellular hairs +
occasional +
persistent +  and ephemeral +
cup-shaped +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
monomorphic +
0 cm0 mm <br />0 m <br /> (45 cm450 mm <br />0.45 m <br />) +
straw-colored +  and dark +
1/3-3 times length of blades +
Sporulating summer–fall. +
not articulate +
not curving +
perpendicular +
not enlarged +
petiolulate +  and sessile +
pinnate-pinnatifid +  and pinnatifid +
reduced +  and not reduced +
Mem. Torrey Bot. Club +
round +, cuplike +, hoodlike +, reniform +, falcate +  and linear +
2 (?) +  and 3 (?) +
persistent +
serrate;dentate;serrate;dentate +
cuneate +  and inequilateral +
discrete +
reniform +  and oblong +
dictyostelic +, unbranched +  and branched +
creeping +  and erect +
not cordlike +
Cystopteris laurentiana +
Cystopteris +
species +
oblong +  and round +
on rock +  and terrestrial +
epiphytic +  and hemiepiphytic +