Den virtuella floran, close-up photos
World| Dryopteris dilatata | ||
Broad buckler fern | ||
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Etymology
Latin: Dilatata means spread out.
Description
Rhizome: erect, branching.
Frond: 100 cm high by 25 cm wide, deciduous, monomorphic, blade/stipe ratio: 3:1. Stipe: grooved, scales ovate-lanceolate, dark brown with a darker central stripe, vascular bundles: 3-7 in a c-shaped pattern. Blade: 3-pinnate, ovate to lanceolate, herbaceous to somewhat leathery, linear to ovate scales below, absent above. Pinnae: 12 to 15 pair, opposite; pinnules nearest pinnule of the lowest pinnae longer than the next one; costae grooved above, continuous from rachis to costae; margins serrate, spinulose, bending under; veins free, forked. Sori: round, in 1 row between midrib and margin, indusium: reniform, attached at a sinus, sporangia: brown then black, maturity: midsummer to mid fall. Culture
Habitat: acidic woodland.
Distribution: central and northern Europe, across northern Asia.
Hardy to -30°C, USDA Zone 4.
Synonyms
Dryopteris austriaca (Jacq.) Schinz. & Thell., misapplied Polypodium dilatatum Hoffmann Aspidium dilatatum Sm. Dryopteris spinulosa ssp. dilatata (Hoffm.) C. Chr. Lastrea dilatata Presl Nephrodium dilatatum Desv. Polystichum dilatatum (Hoffm.) Schumacher Thelypteris dilatata House |
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Notes
Compare to D. aemula and D. dilatata are sometimes confused, particularly with younger plants. However, mature plants of the former are 3-pinnate-pinnatifid at the base vs. just 3-pinnate for the latter. The former has segments with upturned margins; the latter has downturned margins.
Parents D. expansa and a species not in cultivation, D. azorica. Differs from the former in being 3-pinnate at the base rather than 3-pinnate-pinnatifid. It also has darker scales and the margins tend to curve under.
Compare to D. aemula and D. dilatata are sometimes confused, particularly with younger plants. However, mature plants of the former are 3-pinnate-pinnatifid at the base vs. just 3-pinnate for the latter. The former has segments with upturned margins; the latter has downturned margins.
Parents D. expansa and a species not in cultivation, D. azorica. Differs from the former in being 3-pinnate at the base rather than 3-pinnate-pinnatifid. It also has darker scales and the margins tend to curve under.
Dryopteris dilatata. Illustration from The Cultivated Species of the Fern Genus Dryopteris in the United States, Barbara Joe Hoshizaki and Kenneth A. Wilson, American Fern Journal, 89, 1, (1999), with permission. |
