Bryophytes and Lichens of the Pacific Northwest

Anastrophyllum minutum (Schreb.) Schust. var. minutum (Lophoziaceae) is reported as new to the Siskiyou Mountains of Oregon and California.  Two recently discovered populations extend the southern limit of the known range in the Pacific Northwest.  This is the first published report of Anastrophyllum minutum in California.  Diagnostic characters of the species needed for recognition in the field and confirmation in the laboratory are summarized and illustrated with photomicrographs.

Anastrophyllum minutum var. minutum has a broadly circumpolar distribution with southern lobes of the range in the Eastern Hemisphere extending into Asia, Africa, and Europe (Frye and Clark, 1945). In the Southern Hemisphere it is reported from disjunct localities on Kerguelen Island, in South Africa, and at high elevations sites in New Guinea and Borneo (reviewed in Schuster, 1974).  In eastern North America the species ranges south in the Appalachian Mountains to North Carolina and Tennessee, at high latitudes across the northern continental interior, and south into Michigan, Wisconsin, and Minnesota (Schuster, 1969).  In western North America it is known from Alaska north of the Arctic Circle, throughout the western cordillera in Canada, and into the Pacific Northwest, with a disjunct occurrence reported from high elevations in Mexico.  Hong (1996) maps the distribution in northwestern North America from known herbarium records and shows three collection sites in northwestern Washington, one site in Idaho, and three sites in northwestern Montana.  In that paper Hong reports the species as new to Oregon and maps a single locality in the coastal range of Curry County, on the Elk River.  Christy and Wagner (1996) also map the distribution in Washington and Oregon, showing two different sites in Oregon, both in the Cascades of the northern half of the state, in Hood and in Linn counties.

It is evident from the sparse record of collections in Oregon that Anastrophyllum minutum is exceedingly rare in the southern corner of its range in western North America.  In the southern part of its northwest distribution the plant occurs on cool wet soils and rocks on shaded cliff faces and ledges, and is generally restricted to higher elevations (Hong, 1996; Christy and Wagner, 1996).  Since it has only been found in the Pacific Northwest at higher elevations in remote areas it is not presently considered threatened or endangered there, but the Oregon Natural Heritage Program classifies it as a List-3 species, requiring more study before its conservation status can be accurately assessed (ONHP, 2000).  Christy and Wagner (1996) suggest that overcollecting by bryologists may present one of the primary threats to persistence of known populations.  Collecting a rare plant from a known locality is, of course, an unacceptable practice in almost every case.  Unless a field identification can be made, however, the inconspicuous stature of the plant and its propensity for dimly lit habitats could increase the probability that it will be unintentionally collected.  Awareness of the characters that enable an accurate field diagnosis could perhaps reduce the likelihood that a population would be inadvertently damaged through overcollecting.  This report summarizes the diagnostic features and habitat preferences needed to recognize Anastrophyllum minutum in the field at the time of collection.

In 1999 I collected Anastrophyllum minutum in the Siskiyou Mountains at two previously unknown localities.  The following two collection records document an extension of the known southern limit of the range in North America and a first published record of the species for the state of California.
 

Oregon: Jackson County, Big Red Mountain, 42º 3' 6"N, 122º 50' 8"W; pure turf on steep slope below north-facing ledges of granodiorite outcrop, east end of ridge; elevation 2134 meters.
8 July 1999, S.L.Jessup 7620 (SOC).

California: Del Norte County, Black Butte, 41º 55' 16" N, 123º 36' 5"W; sparsely intermixed with Pseudoleskea patens at base of dripping andesite cliffs, and as a pure turf in seep, deep in crevice below massive overhanging ledge, north face of butte, just above trees; elevation 1707 meters.
14 June 1999, S. L. Jessup 7408 (SOC).
 

Though small and often inconspicuously situated where it grows, Anastrophyllum minutum can be recognized by a suite of morphological features accessible with a hand lens in the field.  Confirming the identification with diagnostic details of leaf cell size, cell wall thickness, and oil body morphology requires a compound microscope.  The diagnostic combination of traits can be summarized in six steps: 1) small erect or ascending stems (0.7 to 1.5mm wide) in dense turfs or sparsely intermixed with other bryophytes, 2) growing on damp soil or rock in cool deeply shaded high elevation sites, typically on north slopes or dripping faces of cliffs, 3) subtransverse-succubous insertion of equally-lobed lateral leaves, having acute sinuses and subtly acuminate lobe tips, 4) complete absence of underleaves, and with a marked dorsiventral asymmetry, 5) gemmiferous stems bearing dense terminal clusters of dark red to scarlet angular few-celled gemmae, 6) evenly thick-walled subquadrate median leaf cells, generally 15-24m, typically containing two to five finely papillose oil bodies.

Figure 1a. Red Mountain plants shown at low magnification.
The stems, including leaves, are about 1.0 mm in diameter.

Figure 1b. Red Mountain plant at slightly higher magnification showing stem leaves. Note the essentially transverse insertion of leaves. Leaves are typically strongly canaliculate.  Distance between adjacent leaves is approximately 0.5 mm.

Figure 2. Looking down on the mat of plants from Red Mountain. Plants are generally erect in turfs of closely packed stems. Note the dark red gemmiferous stems in the center.  The white dots are conifer pollen grains for scale.

Figure 3. Leaf of plant from the Black Butte collection.  Note the equal acuminate lobes, the broad acute sinus, lack of under leaves, and subtransverse-succubus insertion. Leaf width in this image is about 0.5 mm.

Figure 4. Close up of cells in leaf of plant from Red Mountain.  Note the uniformly thick cell walls and absence of pronounced trigones.  Cells in the middle of the leaf are about 22m in diameter.

Figure 5. Leaf cells from plant in the Black Butte collection.  Cells have a uniformly thick wall with only slight formation of collenchyma in some parts of the plant. Cells vary from 12-18m on leaf margins and in the lobes. Cells in this leaf are about 15m in diameter.

Figure 6.  Oil bodies in leaf of plant from the Black Butte collection. Cells typically have just a few (2-5) relatively large oil bodies, imaged here with a 50x oil immersion lens.

Figure 7. Oil bodies imaged at 1000x oil, phase 2.  Note the finely papillose, or botryoidal, texture of the oil bodies.

Figure 8.  Angular gemmae from plants in the Black Butte collection, imaged at 400x phase 2.  Gemmae are usually 2 to 4 cells, and have a cuboidal to somewhat star-shaped form.

Figure 9.  A single gemma from plant in the Black Butte collection, imaged at 1000x oil, phase 2.

Figure 10. Gemmae from plants in the Red Mountain collection, imaged at 200x phase 2.  Gemmae are frequently wine red to dark brick red.  Gemmiferous stem tips are visible as distinctly red patches at the tip of individual stems with a 10x hand lens.
 

A search for Anastrophyllum minutum requires considerable logistical planning and exertion to attain the base of remote north-facing mountain cliffs where late snowmelt and perennial seepage occur.  Searching a likely site for this species involves particular attention to dark recesses and crevices, narrow dimly lit crags, and the undersides of large overhangs. Reaching deep into fissures in the rock beyond the lighted opening may reveal to the touch a fine damp pad of tightly packed plants. Care should be taken at this point to pinch just enough of the turf to make a preliminary determination.  Surprisingly little material is needed to confirm the species, and even a thumbnail sized pinch will serve as an adequate voucher.  The Black Butte collection cited above is about 3 square centimeters in its entirety.  The Red Mountain collection is over twice that size.

Certainly other localities remain to be found farther west in the Siskiyou Mountains and farther south in other ranges of the Klamath Mountains of California.  Likely areas include Preston Peak and the Devil's Punchbowl, the Marble Mountains, the Salmon Mountains, the China Mountains, the Trinity Alps, and the Yolla Bolly Mountains.  The persistence of an Anastrophyllum minutum population at any given site may hinge on the integrity of a few delicate patches of the plant occupying the narrow confines of the limited niche available at that locality. While continued research into the biogeographic distributions of bryophytes is a valuable contribution to our science, awareness of the fragility of the populations we visit and a sensitive knowledge of the plants we collect when we collect them are the best protections against the threat of extirpation through overcollecting.
 

Acknowledgements

Thank you to the students in my Siskiyou Field Institute course, Bryophytes of the Klamath Mountains, who accompanied me on the trip to Black Butte and cheerfully endured scrambling through dense brush, clambering over treacherous boulders, and navigating narrow slippery ledges in the quest for seldom seen bryophytes. I would also like to thank my wife, Laura, for providing helpful comments on an early draft of this paper.

Literature Cited

Christy, J. A. and D. H. Wagner 1996. Guide for the identification of rare, threatened, or sensitive bryophytes in the range of the spotted owl, Western Washington, Western Oregon, and Northwestern California. USDI Bureau of Land Management, USDA Forest Service, The Nature Conservancy, and Northwest Botanical Institute.

Frye, T. C. and Lois Clark 1945. Hepaticae of North America, Part III. University of Washington Publications in Biology 6(3): 337-564.

Hong, W. S. 1996. Anastrophyllum in Western North America. Bryologist 99(1): 85-90.

Oregon Natural History Program, internet web site accessed in December 2000. http://ocelot.tnc.org/nhp/us/or/.

Schuster, R. M. 1969. Hepaticae and Anthocerotae of North America East of the Hundredth Meridian, Volume II. Columbia University Press, New York and London.

Schuster, R. M. 1974. The Hepaticae of West Greenland from ca. 66º N to 72º N. Meddelelser om Grønland Udgivne af Kommissionen for Videnskabelige Undersøgelser I Grønland, Band 199(1). C. A. Reitzels Forlag, København.

Copyright © 2000 Steven L. Jessup, Southern Oregon University