Stereocaulon
Stereocaulon Hoffm., 1796
| Common name | Foam Lichens |
|
|---|---|---|
| Field Characters & Notes |
Fruticose, shrub-like or crustose tripartite cephalolichens. Similar in size to Cladonia, but with a different morphology and anatomy. Thalli composed of grey pseudopodetia (=stalks) that are solid and fibrous. The pseudopodetia may be smooth or develop a thick, often pinkish tomentum. The pseudopodetia support phyllocladia which are corticate, white to pale-green leaf-like outgrowths with green algae, ranging in shape from squamulose to grain-like, corraloid or wart-like. Cephalodia are present in most species, ranging from small, spiky, fibrous colonies to bluish grey grains; they contain mostly Nostoc or Stigonema. The cephalodia are buried in tomentum on stalks or held near the attachment points fo the phylocladia. This genus requires more work in Alberta – always note substrate, degree of attachment and orientation (erect vs decumbent) on collections to aid in later identification. | |
| Similar genera |
Cladonia: majority have hollow podetia, never have cephalodia. | |
| Ecology | Mostly terricolous and saxicolous. It appears most species are fairly restricted in range in Alberta, but at least one (S. tomentosum) can be found in most forested regions and (rarely) in the parkland. | |
| Chemistry | Chemistry variable but all have atranorin. | |
| Molecular support |
All samples that we attempted to sequence to date have failed. More work is required. | |
| Links |
-
- Stereocaulon sp., AB
-
- Stereocaulon paschale, with spiky cephalodia, Duckett Bay, SK, PMAE C95.2.12720
-
- Stereocaulon cephalodium squash with filamentous Stigonema cyanobacteria
-
- Stereocaulon sp., Lac la Jeune region, BC
-
- Stereocaulon sp.
-
- Stereocaulon paschale, with small granular cephalodia, Thunder Bay region , ON, PMAE C93.10.182
Species and varieties recorded, or with high potential to be found in Alberta: 18
- S. alpinum Laurer ex Funck – ACIMS, ABMI
- S. arcticum Lynge – BC [UBC], Alaska[NA]
- S. botryosum Ach. – ACIMS
- S. condensatum Hoffm. – ACIMS, Mountains in BC [UBC]
- S. coniophyllum I. M. Lamb – Mountains in BC [UBC]
- S. glareosum (Savicz) H. Magn. – ACIMS
- S. grande (H. Magn.) H. Magn. – ACIMS, ABMI
- S. intermedium (Savicz) H. Magn. – NE USA, Alaska [NA]
- S. myriocarpum Th. Fr. Glacier Nat. Park in Rockies, BC [NA]
- S. paschale (L.) Hoffm. – ACIMS
- S. pileatum Ach. – ACIMS [Reported but false], BC, Ontario [NA]
- S. rivulorum H. Magn. – ACIMS
- S. sasakii Zahlbr. var. simplex (Riddle) I. M. Lamb – ACIMS (not var)
- S. sasakii var. tomentosoides I. M. Lamb – ACIMS (not var)
- S. saxatile H. Magn. – ACIMS
- S. spathuliferum Vainio – Washington, Oregon, BC [NA]
- S. subcoralloides (Nyl.) Nyl. – BC, Ontario, Alaska [NA]
- S. tomentosum Fr. – ACIMS, ABMI
- S. vesuvianum Pers. – BC, Ontario, N USA [NA]
RENR Students: Know the genus as well as key morphological traits and terms (also covered in Brodo et al. 2001 and Goward 1999).
No species level key available: click here for a doc Key to the Fruticose Lichen Genera v.2025-2
Resources
Thomson 1984, McCune and Geiser 2009, Goward 1999. Brodo et al. 2001, Brodo 2016
