Racomitrium brevipes Kindb. in Mac.
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Synonym: Bucklandiella brevipes (Kindb. in Mac.) Bednarek-Ochyra & Ochyra
Special status: NONE
Recognition: Plants are a bit smaller than typical Bucklandiella heterosticha, a bit darker at the tips of the shoots. It is much more similar to Racomitrium sudeticum, such that Lawton thought this was merely a form of that (Lawton 1971, 1972). Racomitrium brevipes shares a bistratose leaf margin with Racomitrium sudeticum and a costa which is mostly 3 cells thick from base to midleaf. However, Racomitrium brevipes has a much wider and flatter costa, 6-9 cells wide adaxially. The costa anatomy is very distinctive. The costa of Racomitrium brevipes is broad, U-shaped, not blocky (quadrate) distally and quite shallow proximally. The pseudopapillose leaf cells in sections appear nearly globular above the vertical walls in section. Pseudopapillae are very prominent, visible even when looking down, with 40X objective, on the dorsal surface of the leaf apex. The hair point is strongly spinulose, even inside the adaxial trough. The hair points are spinulose on the back as well as along their margins.
Distribution: Only recently reported from Oregon (the Kofranek collection) but apparently more abundant. This is an endemic of the Pacific Northwest, from Oregon to Alaska. Found on Mary's Peak, Benton County, and Umpqua National Forest, Douglas County.
Comments: The "pseudopapillae" appear to be very typical papillae, not merely cuticular ridges. There does not seem to be any difference between the papillae described for Racomitrium norrisii and the "pseudopapillae" of species such as Racomitrium brevipes. The pictures provided here should help botanists recognize the various prominences that decorate the leaves of the racomitriums.
Note: In the treatment of this species in the Flora of North America (Ochyra and Bednarek-Ochyra 2007, p. 281) there is a confusing line in the first sentence of the paragraph following the habitat and distribution paragraph. The phrase, ..."and coarsely denticulate, spinulose," seems to connect to the next phrase describing the laminal cells but these adjectives actually refer to the character of the hair points. This is made clear in the formal description which precedes this section.
Racomitrium brevipes; Olive Lake, Grant County, OR. D. Kofranek 2304.
Racomitrium brevipes; Olive Lake, Grant County, OR. D. Kofranek 2304.
Racomitrium brevipes; Olive Lake, Grant County, OR. D. Kofranek 2304.
Racomitrium brevipes; Olive Lake, Grant County, OR. D. Kofranek 2304.
Racomitrium brevipes; Olive Lake, Grant County, OR. D. Kofranek 2304.
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Guide to Racomitrium of Oregon
Created 2007 Northwest Botanical Institute