Woodsia obtusa subsp. obtusa

(Swartz) Torrey
Endemic
Treatment appears in FNA Volume 2.

Stems compact to short-creeping, individual branches usually 5–10 mm diam. Blade coarsely cut and evidently 2-pinnate. Proximal pinnules of lower pinnae usually shallowly lobed or merely dentate. Spores averaging 42–47 µm. 2n = 152.


Phenology: Sporulating summer–fall.
Habitat: Cliffs and rocky slopes (rarely terrestrial), found on a variety of substrates including both granite and limestone
Elevation: 0–1000 m

Distribution

V2 182-distribution-map.gif

Ont., Que., Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.

Discussion

D. F. M. Brown (1964) hypothesized that tetraploid Woodsia obtusa might be an autopolyploid derived from W. oregana. Recent isozyme and spore ornamentation studies indicate, however, that these species are not closely related, and the discovery of a diploid cytotype of W. obtusa suggests a different (albeit autopolyploid) origin for this taxon (M. D. Windham 1993). Tetraploid subsp. obtusa crosses with diploid subsp. occidentalis; the resulting triploids are sterile and have malformed spores. It also hybridizes with W. oregana subsp. cathcartiana to form the sterile tetraploid hybrid known as W. × kansana Brooks.

Selected References

None.

Lower Taxa

None.

"broad" is not a number."thick" is not a number.

Acute (?) +  and Rounded (?) +
Michael D. Windham +
(Swartz) Torrey +
swollen +
Aspidium obtusum +
simple to commonly +
reduced +
roundish +
Ont. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–1000 m +
often +  and glabrous +
Cliffs and rocky slopes (rarely terrestrial), found on a variety of substrates including both granite and limestone +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
glandular +  and entire +
dissected +
monomorphic +
8cm;60cm +
2.5 cm25 mm <br />0.025 m <br /> (12 cm120 mm <br />0.12 m <br />) +
not articulate +
darker +, straw-colored +  and light-brown +
1/5 length of blade;3/4 length of blade +
Sporulating summer–fall. +
not articulate +
longer than wide +
dentate +  and lobed +
New York State, Rep. Geol. Surv. +
round +, cuplike +, hoodlike +, reniform +, falcate +  and linear +
2 (?) +  and 3 (?) +
bicolored;brown +
persistent +
hairlike;lanceolate +
not spiny;entire;dentate +
filamentous +
discrete +
cristate +
dictyostelic +, unbranched +  and branched +
erect +  and horizontal +
Woodsia perriniana +
Woodsia obtusa subsp. obtusa +
Woodsia obtusa +
subspecies +
oblong +  and round +
on rock +  and terrestrial +
epiphytic +  and hemiepiphytic +
41 +, 39 +  and 38 +