Dryopteris intermedia

(Muhlenberg ex Willdenow) A. Gray

Manual 630. 1848.

Common names: Evergreen wood fern fancy fern dryoptère spinuleuse
IllustratedEndemic
Basionym: Aspidium intermedium Muhlenberg ex Willdenow Sp. Pl. 5(1): 262. 1810
Synonyms: Dryopteris austriaca var. intermedia (Muhlenberg ex Willdenow) C. V. Morton Dryopteris spinulosa var. intermedia (Muhlenberg ex Willdenow) L. Underwood
Treatment appears in FNA Volume 2.

Leaves monomorphic, green through winter, 32–90 × 10–20 cm. Petiole 1/3 length of leaf, scaly at least at base; scales scattered, tan. Blade green, ovate, 3-pinnate-pinnatifid, herbaceous, glandular. Pinnae ± in plane of blade, lanceolate-oblong; basal pinnae lanceolate, not reduced, basal pinnules longer than adjacent pinnules, basal basiscopic pinnule longer than basal acroscopic pinnule; pinnule margins serrate, teeth spiny. Sori midway between midvein and margin of segments. Indusia with minute glandular-hairs. 2n = 82.


Habitat: Moist rocky woods, especially hemlock hardwoods, ravines, and edges of swamps
Elevation: 0–2000 m

Distribution

V2 508-distribution-map.gif

N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Ala., Conn., Del., Ga., Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.

Discussion

A related taxon, Dryopteris intermedia subsp. maderensis (J. Milde ex Alston) Fraser-Jenkins, occurs on eastern Atlantic islands.

Dryopteris intermedia and the other taxa in the " D. spinulosa complex" have long confounded taxonomists. Dryopteris intermedia is diploid and is one of the parents of the allotetraploids D. carthusiana and D. campyloptera. Dryopteris intermedia hybridizes with eight species. All hybrids are easily detected by the distinctive glandular hairs on the indusia and, usually, on the costae and costules.

Selected References

None.

Lower Taxa

None.

"not" is not a number. "swollen" is not a number."/3lengthofleaf" is not declared as a valid unit of measurement for this property.

... more about "Dryopteris intermedia"
pinnatifid +
James D. Montgomery +  and Warren H. Wagner Jr. +
(Muhlenberg ex Willdenow) A. Gray +
not reduced +
Aspidium intermedium +
simple to commonly +
3-pinnate-pinnatifid;ovate +
reduced +
leathery;herbaceous to somewhat +
roundish +
Evergreen wood fern +, fancy fern +  and dryoptère spinuleuse +
N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Ala. +, Conn. +, Del. +, Ga. +, Ill. +, Ind. +, Iowa +, Ky. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, Tenn. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–2000 m +
often +  and glabrous +
Moist rocky woods, especially hemlock hardwoods, ravines, and edges of swamps +
caducous +  and persistent +
round-reniform +
monomorphic +
32 cm320 mm <br />0.32 m <br /> (90 cm900 mm <br />0.9 m <br />) +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
1/4 +  and 2/3 +
not articulate +
not +, spinulose +  and serrate +
sessile +  and petiolulate +
inequilateral +
enlarged +  and reduced +
round +, cuplike +, hoodlike +, reniform +, falcate +  and linear +
2 +  and 3 +
persistent +
linear;ovate +
discrete +
Illustrated +  and Endemic +
reniform +  and oblong +
dictyostelic +, unbranched +  and branched +
short-creeping +  and erect +
Dryopteris austriaca var. intermedia +  and Dryopteris spinulosa var. intermedia +
Dryopteris intermedia +
Dryopteris +
species +
anastomosing +  and simple +
epiphytic +  and hemiepiphytic +