Guide to Liverworts of Oregon:Jamesoniella autumnalis (DC.) Steph. var. heterostipa (misapplied)
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Tentative Synonyms: Jungermannnia schusteriana J.D. Godfrey & G. Godfrey; Plectocolea schusteriana (J.D. Godfrey & G. Godfrey) Bakalin.
Misapplication: Jamesoniella autumnalis (DC.) Steph. var. heterostipa (Evans) Frye & Clark was misapplied in earlier versions of these keys.
Special Status: ORNHIC List 1.
Recognition: This plant is recognized from its location and habitat (bottom of Waldo Lake) as much as its morphology. It has succubous leaves which are rounded or more often emarginate. Plants from deeper in the lake have a greater tendency to produce round leaf tips. Underleaves are absent from most stem segments but are produced sporadically. The occasional underleaf is quite large and lanceolate. This feature of underleaf production is one of the main reasons I have used the name J. autumnalis heterostipa since that is what Evans emphasized, in addition to aquatic habitat, in describing this taxon.
Distribution: Found only in the bottom of Waldo Lake, Lane County from ca. 5 m to its deepest point at 120 m. It dominates much of the lake floor from ca. 20 meters to the bottom, forming a continuous carpet over extensive areas (Wagner, et al. 2000).
Comments: It appears this is the world's deepest liverwort. Other Cascade Lakes should be sampled to see if it occurs elsewhere. Studies of Crater Lake and Lake Tahoe have revealed mosses at greater depths than anything in Waldo Lake but have not turned up this liverwort.
It has become apparent to me that the Waldo plant does not belong in Syzygiella. Some of the more complanate forms could be mistaken for a Plagiochila. Recent study of fresh specimens from the outlet stream of Waldo Lake has demonstrated that the dominant of the bottom of Waldo Lake is most likely Jungermannia schusteriana. It will be necessary to compare the Waldo Lake material with the type of Jungermannia schusteriana to settle this issue. If they do not match, it will be necessary to describe a new species for the Waldo Lake liverwort.
Outlet Stream, Waldo Lake, Lane Co., Oregon. DHW
m0736
From 100m deep, Waldo Lake, Lane Co., Oregon. DHW
m0765d.
Oil bodies in median cells. From 100m deep, Waldo Lake, Lane Co., Oregon. DHW m0765d.
Dorsal aspect, male shoot. South Bay, Waldo Lake, Lane Co., Oregon. Larson #2 6-9-90.
Ventral aspect, male shoot. South Bay, Waldo Lake, Lane Co., Oregon. Larson #3 6-9-90.