Interrupted Fern

Interrupted Fern


Interrupted Fern

I like how if I just drop the cone, it will die. If I bury it with leaves and sand it tries to grow back. I like how it’s not perfect. I like how it gets cracked if I put too much weight on it. I like how it’s alive. Maybe that’s why I love growing ferns so much.A very interesting plant for the shady garden, Osmunda claytoniana (Interrupted Fern) is a charming deciduous fern with showy, lance-shaped, divided, pale green sterile fronds surrounding erect, central fertile fronds. The fertile fronds are interrupted in the middle by brown leaflets (spore-bearing pinnae) which typically fall off in mid summer, thus giving this distinctive fern its common name. Interrupted Fern is one of the first ferns to begin growth in spring. The oldest known fossil record of any living fern in the world is over 200 million years old!


When only infertile leaves are present, they are difficult to distinguish from the infertile leaves of Cinnamon Fern (Osmunda cinnamomea). Generally, the petioles of Cinnamon Fern are more brown-woolly than those of Interrupted Fern, especially later in the year, when the latter fern becomes hairless (or nearly so). The leaflets of Cinnamon Fern have persistent tufts of woolly hair at their bases along the rachis, while the leaflets of Interrupted Fern are usually glabrous at their bases from the summer onward. Instead of restricting its sporangia toward the middle of its fertile leaves, Cinnamon Fern produces reddish brown fertile leaves that are covered entirely by sporangia from top to bottom.

In spring, the emerging fiddleheads are striking for their silvery-white appearance. Interrupted Fern does best in moderately damp acid soils, but adapts well to almost any good garden soil in part to full shade.Interrupted Ferns are dimorphicFrond dimorphism: Refers to a difference in ferns between the fertile and sterile fronds., which means that the sterile fronds and fertile fronds are different in appearance. The sterile frondsSterile frond: A frond without sporangia (spore cases). grow in an arching, circular clump emanating from the rhizome.As with the Interrupted Fern, the fertile fronds of Cinnamon Ferns appear in the center of the sterile fronds. However, the Cinnamon Fern's fertile fronds lack the green leaflets on the top half and lower half of the fertile frond, which is characteristic of the Interrupted Fern. In addition, the sterile leaflets of Cinnamon Ferns have persistent tufts of woolly hair at the base.This feature distinguishes the Cinnamon Fern from the Interrupted Fern, which lacks these tufts.(Source: wildadirondacks.org)



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