Guide to Liverworts of Oregon: Anastrophyllum minutum (Schreb. ex Cranz) Schust.
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Synonym: Sphenolobus minutus (Schreb. ex Cranz) Berggr.
Special status: ORBIC List 2
Recognition: Small plants (ca. 1 mm or less wide) with bilobed leaves, + or - like Cephalozia, Cephaloziella, small Marsupella, Lophozia or Nardia. Usually brown, golden-brown, occasionally dark-green. Leaves transversely inserted (vs. Cephalozia & most Nardia; Lophozia). Differs from all these in the botryoidal oil bodies consisting of distinct, small spherules and leaf cell walls being conspicuously evenly thickened but without trigones. Gemmae bright red when present but not seen in Oregon material; Damsholt (2002) mentions that gemma-free forms are found in plants with more widely spaced leaves.
Distribution: Bogs and peaty soil; coast and high mountains. Reported from Curry, Hood River, Jackson, Lane, and Wallowa Counties. Only the Hood River County (Wagner 2369, 2370, OSC) records and a Lane County record (very close to the Deschutes County line) from Chambers Lakes, in the Three Sisters Wilderness (Wagner 2539, 2589) appear to be valid. The Wallowa and Jackson County records are in need of verification. The Curry County record is rejected upon re-examination of original specimens.
Comments: The closest look-alike is Lophozia sudetica which is remarkably similar. It was mistaken for A. minutum by Jessup (2000) because it is the same size, has bilobed leaves, lacks underleaves and has reddish, angular gemmae. I have examined the collections on which this report is based and found that these plants are actually thrifty forms of Lophozia sudetica, a remarkably close look alike. Most contemporary works do not point out this similarity, probably because the assumption is made that knowing whether an Anastrophylum or Lophozia is at hand is easily determined. However, L. sudetica has more secund leaves, especially on more prostrate shoots. It has leaf cells that lack large trigones but the cell walls are not consistently evenly thickened as in A. minutum. The best character for separating L. sudetica from A. minutum is the arrangement of cells in the leaf lobes. These are in distinct, concentric rows radiating from the lobe tips in A. minutum, a feature first noted by Paton (1999).
Anastrophyllum minutum. Mt. Hood, Multnomah Co., Oregon. DHW 2369
Anastrophyllum minutum. Mt. Hood, Multnomah Co., Oregon. DHW 2369.
Anastrophyllum minutum. Mystery Hills, Kenai National Wildlife Refuge, Alaska. Ed Berg B091
Anastrophyllum minutum. Mystery Hills, Kenai National Wildlife Refuge, Alaska. Ed Berg B091
Anastrophyllum minutum. Leaf lobe with cell rows indicated. Mystery Hills, Kenai National Wildlife Refuge, Alaska. Ed Berg B091