Sphagnum andersonianum
Sphagnum rubiginosum
Anderson's sphagnum
leaves lingulate, 0.9–1.2(–1.4) mm, apex rounded-erose to sometimes slightly apiculate, border moderately strong and broadened at the base (to 0.8 the width);
hyaline cells rhombic, 0–1-septate, usually efibrillose.
leaves broadly lingulate-spathulate to spatulate, widest at base and/or distal third, usually narrower in the mid region, 1–1.3 mm, apex narrowly to broadly truncate and ± fimbriate-lacerate, border narrow distally and expanded proximally to 0.25 width or more;
hyaline cells efibrillose, irregularly rhombic to subquadrate, many cells 2–4-septate.
not or slightly 5-ranked, lax.
unranked.
ovate, 0.8–1.4 mm, distinctly concave, straight, apex dentate and involute;
border entire;
hyaline cells on convex surface with elliptic pores along the commissures, grading from smaller pores near the apex to larger pores at the base, concave surface with large round pores on the proximal portions of the leaf.
ovate-lanceolate, 1.1–1.4 mm, slightly concave, straight, apex involute;
hyaline cells on convex surface grading from aporose to few small round pores near apex to numerous semi-elliptic pores along commissures in middle and base of leaf, concave surface with a few large irregular to circular pores (1–4) occupying most of the cell width.
dioicous.
autoicous.
18–24 µm; coarsely papillose on both surfaces;
proximal laesura less than 0.5 the length of the spore radius.
20–27 µm, moderately granulate-papillose on both surfaces, distinct raise Y-mark sculpture on distal surface;
proximal laesura less than or equal to 0.5 spore radius.
fascicles with 2 spreading and 1–2 pendent branches.
fascicles with 3(4–5) spreading branches and 1–2 pendent branches.
Sphagnum andersonianum
Sphagnum rubiginosum
Sporophytes are uncommon in Sphagnum andersonianum. Its distribution is uncertain due to past taxonomic confusion with S. rubellum, S. capillifolium, and other closely related species in sect. Acutifolia. This is one of the most hydrophytic species of the section and is often associated with S. angustifolium, S. fallax, and S. rubellum. It is often not easily distinguished from S. rubellum, with which it may intergrade in a manner similar to that already demonstrated for S. rubellum and S. capillifolium by N. Cronberg (1997, 1998). Phenotypically S. andersonianum is a softer, paler plant with branch leaves that are more ovate and concave on branches that are less 5-ranked. Sphagnum rubellum also has the branch leaves sometimes subsecund while in S. andersonianum they are straight. Ecologically S. rubellum is an open mire species of usually ombrotrophic conditions, where it often forms hummocks, while S. andersonianum occurs in more sheltered sites where there is some mineral influence. Where they occur together, S. rubellum is on the tops of hummocks and S. andersonianum is on the hummock sides and bases. Microscopically S. rubellum has stem leaves with at least some of the hyaline cells twice septate, while in S. andersonianum none are twice septate.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The sporophytes of Sphagnum rubiginosum are common. The geographic distribution is unclear because of the species’ recent description and possible confusion with S. girgensohnii. It is clearly distinct from S. girgensohnii in coloration, number of spreading branch fascicles, the common occurrence of sporophytes (rarely found with S. girgensohnii, and spore morophology. The conspicuous three spreading branches will separate this from all species of sect. Acutifolia except S. quinquefarium. The latter has 5-ranked branch leaves, while those of S. rubiginosum are unranked.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
USDA Plants Database- Local floras:
BC - Local Web sites:
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
