SPECIES FACT SHEET
Common Name: jelly flakes
Scientific Name: Collema undulatum Laurer ex Flowtow var. granulosum
Degel.
Division: Ascomycota
Class: Ascomycetes
Order: Lecanorales
Family: Collemataceae
Technical Description: Thallus cyanolichen, gelatinous, 3-6 cm diameter,
blackish when dry and more or less transparent olive greenish to black and
rubbery when wet; lobes rounded or irregular, 2-4 mm wide, with coarsely
wavy margins sometimes ascending, well-formed lobes concave or channelled;
lobes 140-300 µm thick and the edges of the tips not swollen. Isidia globular,
formed from the top surface and increasing in size with age to about 0.1-0.2
mm wide. Apothecia absent or occasionally present, 1-1.5 mm diameter, with
red-brown discs initially flat and becoming convex, the margins even,
persistant, and of same color as the thallus (thalline margin). Spores oblong,
hyaline, 17-30 x 6.5 - 9 µm, 3-septate (Degelius 1954). Photosynthetic partner
(photosymbiont) the cyanobacterium Nostoc. Chemistry: all spot tests
negative.
Distinctive characters: Gelatinous lichen on calcareous seeps with globular
isidia. Similar species: Collema fuscovirens is similar to C. undulatum var.
granulosum, but the thallus of C. fuscovirens is thinner (110-200 µm),
pustulate, less distinctly undulate, more often prostrate (Nash et al. 2004);
isidia can be larger (to 0.3 mm) and can be found on margins as well as top
surface of the lobes (Hinds & Hinds 2007); and it has submuriform spores with
3 transverse and one longitudinal septa. Specimens without apothecia can only
be distinguished by thallus thickness, form, and possibly by size and
placement of isidia. Thalli of L. undulatum found so far in Oregon have been
sterile and so poorly developed that it is unclear whether they are C. undulatum
var. granulosum or C. fuscovirens (Stone, personal observation). Leptogium
plicatile is gelatinous and grows in similar habitats (Nash 2004). It has
narrower, thinner lobes, is more closely attached to the substrate and has an
upper and lower cortex of one layer of isodiametric cells, although these are
often difficult to see. The cortex is best seen by looking at a cross-section of the
thallus under a compound microscope.
Other descriptions and illustrations: Brodo et al. (2001): 287; Degelius
(1954); Goward et al. (1994): 45; Hinds and Hinds (2007): 232; Nash et al.
(2004): 80; Purvis et al. (1992):226, photos by D.Stone (below).
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Life History:
Details for Collema undulatum var. granulosum are not
documented. It appears to spread mainly by isidia, but in this species the
isidia are heavy enough to limit dispersal. Spores and isidia are probably
spread by wildlife and water.
Range, Distribution, and Abundance: North America; Europe; Greenland;
Japan (Degelius 1974). In the Pacific Northwest, Alaska south to Oregon. In
Oregon it occurs west of the Cascade Mountains, and the only known record is
in Jackson County, north of Gold Hill. Possibly occasional and overlooked.
National Forests: none documented; suspected on Umpqua and Rogue RiverSiskiyou NFs. BLM Districts: documented on Medford District; suspected on
Roseburg District because of similar habitat.
Habitat Associations: On periodically moistened calcareous rocks or on
mosses over rocks, occasionally on soil. In Oregon it was found in full shade on
a steep upper slope of exposed non-calcareous bedrock, with seeps providing
lime to the rock surface. Forest type is Pseudotsuga menziesii.
Threats: Disturbance of rock outcrops or changes in groundwater flow.
Conservation Considerations: Revisit known localities and monitor the
status of populations. Search for new populations on federal and state lands.
Surveys in suitable habitat and protection of known sites should be a priority.
The best opportunity for conservation would be on federal land and in state
parks.
Conservation rankings: Global: G4G5; National: NNR; Oregon Natural
Heritage Information Center: List 3 (S1?).
Collema undulatum var. granulosum is rather rare in North America (Nash et al.
2004).
Preparer: Daphne Stone, with edits from John A. Christy
Date Completed: March 2009
References:
Brodo, I. M, S. D. Sharnoff, & S. Sharnoff. 2001. Lichens of North America.
Yale University Press, New Haven and London. 795 pp.
Degelius, G. 1954. The lichen genus Collema in Europe: Morphology,
Taxonomy, Ecology. Symbolae Botanicae Upsaliensis 13(2): 1-499.
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Goward, T., B. McCune, & D. Meidinger. 1994. The Lichens of British
Columbia. Part 1. Foliose and Squamulose Species. British Columbia
Ministry of Forests. Crown Publications Inc., Victoria, B.C. 181 pp.
Hinds, J. W. & P. L. Hinds. 2007. The Macrolichens of New England. Memoirs
of the New York Botanical Garden Volume 96, New York Botanical Garden
Press, New York. 584 pp.
Nash, T. H., B. D. Ryan, P. Diederich, C. Gries and F. Bungartz. 2004. Lichen
Flora of the Greater Sonoran Desert Region, Vol 2. Lichens Unlimited,
Arizona State University, Tempe, AZ. 742 pp.
Oregon Natural Heritage Information Center. 2007. Nonvascular Plant
Rankings
2007.
http://oregonstate.edu/ornhic/documents/2007_t&e_book.pdf.
Accessed
28 Feb 2009.
Purvis, O, W., B. J. Coppins, D. L. Hawksworth, P. W. James & D. M. Moore,
eds. 1992. The Lichen Flora of Great Britain and Ireland. Natural History
Museum Publications, London. 710 pp.
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Fig 1. Habit. Fig. 2. Cross-section showing isidia. Fig. 3 upper surface, showing isidia formation.
Photos by Daphne Stone, 2008.
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