Racomitrium aciculare (Hedw.) Brid.
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Synonym: Codriophorus acicularis (Hedw.) Bednarek-Ochyra & Ochyra
Special status: NONE
Recognition: Habitat is an important character for this species. It is restricted to riparian zones, primarily in the splash zone of medium sized streams. In this habitat, it is recognized by the teeth at the apex of the leaf. These are small but distinct. With experience they can be seen with a 10X handlens. The only species to confuse with R. aciculare are both rare. Racomitrium mollis has been found once at high elevations on the east slope of the Cascades in Klamath County. It is distinguished by rounded leaf tips which are cucullate, and a shorter costa. Racomitrium norrisii closely resembles R. aciculare and can only be positively determined by seeing its bistratose leaves under a microscope. Racomitrium norrisii has not yet been found in Oregon.
Distribution: Widespread at all elevations; restricted to streamside habitats.
Comments: Bednarek-Ochyra (2006) mentioned that in California one might occasionally find specimens of R. aciculare with bistratose patches in some leaves. These could be confused with R. norrisii. She says (p. 60), "C. acicularis has strongly papillose laminal cells with very large, flat papillae covering the cell walls and major part of the lumina, leaving only a narrow central slit, whereas C. norrisii has almost glabrous older leaves and in younger leaves the papillae cover only the cell walls, leaving the lumina without cuticular thickenings." It is hard to understand the the difference between the papillae described here and the "pseudopapillae" of species such as Racomitrium brevipes.
Cherry Creek, Klamath Co., Oregon. DHW
8357
Racomitrium aciculare - Idaho County, Idaho. DHW 802
Racomitrium aciculare - Idaho County, Idaho. DHW 802
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Guide to Racomitrium of Oregon
Created 2007 Northwest Botanical Institute