Polystichum munitum
From Biocrawler, the free encyclopedia.
| Western Sword Fern | ||||||||||||||
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| Polystichum munitum (Kaulfuss) K. Presl |
The Western Sword Fern (Polystichum munitum) is an evergreen fern, and one of the most abundant ferns in the flora of western North America.
The dark green fronds of this fern grow as long as 5 ft, but more often 3 ft, in a tight clump. They are once-pinnate, with the pinnae alternating on the stalk. Each pinna has a small upward-pointing lobe at the base and the edges are serrated with bristly tips. Stalks spread out radially from a round base. Individual fronds live for several years and remain attached to the rhizome after withering. The round sori occupy two rows on either side of the midrib of each pinna and are covered by a centrally-attached, umbrella-like indusium with fringed edges. They produce light yellow spores.
The favored habitat of this fern is the understory of moist coniferous forests at low elevations. It does best in a well-drained acidic soil of rich humus and small stones. Sword ferns are very tough, and can survive occasional dry periods, but do well only with consistent moisture, light sunlight, and prefer cool weather to overly warm. They also respond well to regular, light applications of fertilizer.
References
- Flora of North America: Polystichum munitum (http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200004619)
- Polystichum munitum, the Sword Fern (http://www2.ups.edu/faculty/kirkpatrick/fieldbotany/family_pages/Polypodiaceae/polystichum_munitum.htm)
