Aphanorrhegma serratum

(Wilson & Hooker) Sullivant in A. Gray

in A. Gray, Manual, 647. 1848,

Basionyms: Schistidium serratum Wilson & Hooker
Treatment appears in FNA Volume 27. Treatment on page 181. Mentioned on page 195.
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Plants gregarious to scattered; leaves slightly twisted when dry; perichaetial leaves erect-spreading when dry, exposing the capsule.

Phenology: Capsules mature (Jul) Sep–Dec.
Habitat: Soil, clay, along creeks or trails in places subject to inundation, rarely among other mosses
Elevation: low to moderate elevations

Distribution

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Ont., Que., Ark., Conn., D.C., Fla., Ill., Ind., Iowa, Kans., Ky., La., Md., Mich., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., Tenn., Va., Vt., W.Va., Wis.

Discussion

Aphanorrhegma serratum resembles the sympatric Physcomitrella patens, from which it differs in its capsule’s regular line of dehiscence and collenchymatous exothecial cells; it also grows occasionally with Physcomitrium immersum. The latter two species are small and both have an immersed operculate capsule. Physcomitrium immersum is distinguished by a distal line of dehiscence (versus equatorial in A. serratum), the presence of an annulus of small cells, the thin-walled (versus collenchymatous) exothecial cells, and an urceolate rather than a globose operculate urn. Aphanorrhegma serratum has been reported from Texas by H. A. Crum and L. E. Anderson (1981). I have seen only one collection (Duke) from that state, but the specimen lacks collenchymatous exothecial cells, bears a distinct annulus, and hence is here referred to Physcomitrium immersum.

References

None.

Lower Taxa

No lower taxa listed.