''Dryopteris marginalis'', vernacularly known as the marginal shield fern or marginal wood fern, is a

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

species of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

found in damp shady areas throughout eastern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, from Texas to Minnesota and Newfoundland. It favors moderately acid to circumneutral soils in cooler areas but is fairly drought-resistant once established. In the warmer parts of its range, it is most likely to be found on north-facing non-calcareous rock faces. It is common in many altitudes throughout its range, from high ledges to rocky slopes and stream banks. Marginal wood fern's name derives from the fact that the sori are located on the margins, or edges of the leaflets.

Description

''Dryopteris marginalis'' is an evergreen fern throughout its range, along with Christmas fern (''

Polystichum acrostichoides ''Polystichum acrostichoides'', commonly denominated Christmas fern, is a perennial, evergreen fern native to eastern North America, from Nova Scotia west to Minnesota and south to Florida and eastern Texas.stipe, or stem which supports the leaf is approximately 1/4 the length of the leaf and covered in bright golden brown scales. The stipe itself is grooved on the upward-facing side and dark red-brown at the base and becoming green further up the leaf. The leaf is a dark blue-green and thick and leathery in texture. It grows 1–2 ft in height and approximately 6 in wide. Each leaf is broken up into leaflets which are arranged on either side of the main stalk. The tips of these leaflets are generally curved toward the tip of the leaf. These leaflets themselves are divided into subleaflets which are blunt-tipped and either serrated or lobed. The fertile leaflets (leaflets bearing sori and spores) are similar to the fertile leaflets in size and appearance. The round sori are located on the margins of the leaf tissue. Before the sori are ripe they start gray then they turn an interesting blue-violet color before finally turning brown when they are mature. The sori are covered in a kidney-shaped

indusium A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient ...

which is smooth.

Distribution and habitat

''Dryopteris marginalis'' has a wide distribution in the northeastern USA. It was found for the first time in Minnesota in 1981, and likely was part of the native flora for a long time but overlooked because of its rarity and its close resemblance to related species. It is listed as a threatened species in Minnesota, not so much because the species is currently threatened, but because there is only one population found on an east-facing bluff composed of sandstone that is capped with limestone. In other parts of its range it is found in woods, on talus-slopes, in rocky areas and walls, on wooded slopes and ravines, and at the edges of woods, streams and roads.

Cultivation

''Dryopteris marginalis'' is grown in gardens in part to full shade, it is an evergreen non-spreading fern that forms a vase-shaped clump of leathery, deeply cut fronds. It is used in shade gardens, rock gardens, and native plantings. There are no serious insect or disease problems that affect it and it is winter hardy in USDA zones 3-8. ''Dryopteris marginalis'' is known to form hybrids with 10 other species and some of the hybrids are common, they can be identified by the malformed

spores In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

and sori which are not quite on the margins of the leaves. Dryopteris marginalis10.jpg, Showing leaflets Dryopteris marginalis sori.jpg, Showing sori Dryopteris_marginalis-parsons.jpg, Botanical illustration Dryopteris marginalis01.jpg, Scales on stalk

References

External links

Connecticut Botanical Society: ''Dryopteris marginalis''
{{Taxonbar, from=Q3459756 marginalis Flora of Ontario Flora of North America Plants described in 1753 Taxa named by Carl Linnaeus