Plants in soft, loose tufts, light to dark green or yellow-green. Stems 0.2–3.5 cm; radiculose. Stem leaves obovate to long-lanceolate; margins entire or serrate distally; apex obtuse, acute, or acuminate; costa ending in or before apex; proximal laminal cells rectangular; distal cells oblong-hexagonal. Sexual condition dioicous (autoicous in S. pensylvanicum). Seta 0.2–15.5 cm, flexuose or twisted. Capsule not cleistocarpous, red-, orange-, or yellow-brown, or orange-red, cylindric; hypophysis with color greatly differentiated from urn, globose to turbinate, sometimes umbrelliform, elongate, usually much larger, wider than urn; annulus absent; operculum conic to hemispheric, blunt to apiculate; peristome double; exostome teeth 16, sometimes connate, reflexed when dry, inflexed when moist, of 3 layers of cells. Calyptra conic-mitrate, small, reaching hypophysis, not constricted beyond base. Spores 7–13 µm, smooth.

Distribution

Nearly worldwide, except Antarctica, tropical to subarctic regions.

Discussion

Species 11 (6 in the flora).

Plants of Splachnum are often shiny, entomophilous and coprophilous, and all circumboreal species appear to be restricted to growing on herbivore dung. The genus is characterized by its chambered exostome teeth as well as several species having greatly enlarged, colorful, differentiated hypophyses. The spores of this genus are sticky; the smooth setae usually continue growing after the spores mature. The stems are loosely foliate and simple or 2-fid. The stem leaves are erect or erect-spreading, usually more crowded toward stem apices, more or less contorted when dry, and usually spreading when moist. The perigonia are cupulate and large; the perichaetia are terminal on the stems or branches with leaves fewer and smaller. The exothecial cells are quadrate-hexagonal and rectangular at the capsule base, and transversely elongate in distal rows. The columella is short-exserted.

Selected References

None.

Lower Taxa

Splachnum ampullaceum, Splachnum luteum, Splachnum pensylvanicum, Splachnum rubrum, Splachnum sphaericum, Splachnum vasculosum

Key

1	Hypophysis ± globose, ovoid, or turbinate, much wider than urn	> 2
1	Hypophysis umbrelliform, or if globose or narrowly pyriform, not much wider than urn	> 3
2	Hypophysis yellow or pink, rarely reddish; leaves narrowly oblong-obovate to long- lanceolate; margins spinose-dentate distally; apices slender-acuminate.	Splachnum ampullaceum
2	Hypophysis red-purple when moist; leaves ovate to obovate; margins entire; apices blunt, rounded, or obtuse.	Splachnum vasculosum
3	Hypophysis umbrelliform, much wider than urn	> 4
3	Hypophysis spheric, narrowly pyriform, or obovoid, not much wider than urn	> 5
4	Hypophysis discoid-umbrelliform, yellow; leaf margins serrate to subentire distally.	Splachnum luteum
4	Hypophysis convex-umbrelliform, bright magenta red; leaf margins coarsely serrate distally, toothed nearly to base.	Splachnum rubrum
5	Setae longer than 1 cm; hypophysis green, red-brown when dry; leaves broadly obovate; apices abruptly short- to long-acuminate.	Splachnum sphaericum
5	Setae shorter than 1 cm; hypophysis greenish, dark red or purplish distally; leaves long- lanceolate; apices slenderly long-acuminate.	Splachnum pensylvanicum