Acaulon muticum

(Hedwig) Müller Hal.

Bot. Zeitung (Berlin) 5: 99. 1847,

Basionyms: Phascum muticum Hedwig Sp. Musc. Frond., 23. 1801
Treatment appears in FNA Volume 27. Treatment on page 639. Mentioned on page 638.
Plants elliptic to globose, ca. 2 mm. Stem leaves cuspidate, broadly channeled; laminal cells smooth. Seta short, about 0.3 the diameter of the capsule. Spores spheric to elliptic, 30–50 µm, papillose or nearly smooth.

Distribution

V27 942-distribution-map.gif

Temperate areas of the Northern Hemisphere, Africa.

Discussion

Varieties 2 (2 in the flora).

As H. A. Crum (1969) and A. J. Grout (1939) pointed out, American specimens reported as Acaulon rubrum are A. muticum var. rufescens. These plants are often small, rather three-sided and may be confused with A. triquetrum. The leaves of both varieties stain red, at least in blotches, in KOH, and they intergrade to some extent.

References

None.

Key

1 Plants yellow-brown in nature, spores papillose- punctulose Acaulon muticum var. muticum
1 Plants yellow- to red-brown in nature, spores smooth or papillose-punctulate Acaulon muticum var. rufescens