Tuesday, November 4, 2008

Ludwigia alternifolia

An amazing fall display has dragged me out of a posting hiatus. Seedbox, or Bushy Waterprimrose, has yellow flowers on a 2-3' stalk with elongate leaves during the summer, but in the fall bears yellow and red foliage, which drops to reveal these squarish seeds. As the name denotes, this plant enjoys moist conditions.

Thursday, February 28, 2008

Dryopteris cristata

Forming small evergreen rosettes, the fronds of the crested wood fern reach 2.5 feet in height. It is found in shallow marshes and swamps across the North American continent. Full sun is tolerable, but thrives with 2-3 hours of sun. Once established, will tolerate dry shade. Hardy to -35 degrees.

Basal pinnae are reduced, while fertile pinnae are rotated perpendicular to the taller, erect blade. Blade is narrowly lanceolate, leaflets are pinnate-pinnatifid. Also, a key characteristic of the Dryopteris family, the indusium takes on a broad horseshoe shape in midsummer.

Also known as buckler fern, shield fern, and narrow swamp fern.

(Picture from Mike Rosenthal <www.msrosenthal.com>)

Thursday, February 14, 2008

Dryopteris carthusiana

Found in low woods, swamps, thickets, and rocky slopes, the toothed woodfern prefers wet to moist soils. Its delicate fronds grow in a vase-like crown, enabling a semi-evergreen growth, characteristic of the woodfern or Dryopteris family. Its height ranges from 1'-2.5', forming colonies. One form of identification is the bottommost pair of pinnae, where the basal pinules (closest to the main stalk) should be the longest. On Dryopteris intermedia, the pinules one away from the main stalk are the longest. The green stipe will have light brown scales on its surface. Sori are located near the tips of veins.

Spinulose woodfern is threatened by hydrolic changes and browsing.

(Picture from National Museums and Galleries of Northern Ireland)

Sunday, January 27, 2008

Dennstaedtia punctilobula

Most often found in a carpet of colonies, hay-scented fern grows from 1'-3' in dry or moist sites in open understory or pasture. Fronds are light green, in the form of large arching triangles 3"-5" wide with bi/tri-pinnate, irregularly cut pinnae. Hairs can be found on the rachis and stipe. Fronds display phototropism.

Aggressive spreading have made it a weed in some areas, and studies in New England have considered its dominance an obstacle to forest regeneration. Unappealing to deer, the fern continues to grow where its competitors have been eaten, and unless shade tolerant trees create a thicker canopy, it will grow unfettered.

Bruised fronds smell of hay.

(Picture from Virginia Department of Conservation)

Sunday, January 20, 2008

Botrychium virginianum

Growing to a height of 1-2 feet, the rattlesnake fern is found in rich woodlands. The ternately compound fronds feel soft and display stems that are tan/pinkish near the base, becoming greener in the extended portions. A single fertile frond holds clusters of yellow grape-like spore clusters above the infertile fronds.

Plants can be divided in the spring after new growth begins, but propagation from spores is difficult. Spores need complete darkness and a mycorrhizal relationship to support the gametophyte. In the greenhouse, a mix of 1 part peat, 2 parts loam, and 1 part sand, consistently moist is needed.

This fern will do well in a moist garden area, and has a unique texture and form that can be utilized by the garden designer. Can also be boiled and eaten.

Botrys is greek for a cluster of grapes, while the spore clusters are said to resemble a rattlesnake's rattle.

(Picture from Ontario Ferns)

Wednesday, January 16, 2008

Athyrium filix-femina ssp. asplenioides

Wide-spreading where its rhizomes are constantly wet, and tolerates most soil conditions. Enjoying dappled sun or shade, the southern lady fern grows bipinnate-pinnatifid fronds in a false crown, resembling a bouquet of christmas tree forms. It can reach 2'-3' and spreads by offsets of plant colonies. It should have protection from wind and a locale of high humidity.

While this fern may be confused with Dryopteris species, the lady fern's leaves are larger, and deciduous, not evergreen. Differences also include the lady fern's slender spore-bearing structures, as opposed to the wood fern's round sori.

These ferns are found in deciduous woodlands, shaded seeps, and swamp edges.

(Picture from Meadowbrook Nursery)

Tuesday, January 15, 2008

Asplenium platyneuron

Found in rocky areas with excellent drainage, the thin fronds of the Ebony Spleenwort reach upwards in a disordered, glossy mass. Most likely, one or two leaves will be growing flat on the ground. Can tolerate full shade, and provides evergreen color along with dark purple central stipes. It grows up to 15" tall, and in May to September, the more erect fertile fronds develop oblong, herringbone sori on their undersides.

Its tendency to appear in disturbed soil and masonry make it a nice candidate for ruin gardens, rock gardens, or woodlands. They prefer subacid rock or mortar joints/limestone.

Interesting fact: A. platyneuron is the only North American fern that is also found in South Africa.

(Picture from Mobot.org)