Physcomitrella readeri

(Müller Hal.) I. G. Stone & G. A. M. Scott

J. Bryol. 7: 604. 1974,.

Basionym: Ephemerella readeri Müller Hal. Hedwigia 41: 120. 1902
Synonyms: Physcomitrella californica H. A. Crum & L. E. Anderson Physcomitrella patens subsp. californica (H. A. Crum & L. E. Anderson) B. C. Tan Physcomitrella patens subsp. readeri (Müller Hal.) B. C. Tan
Treatment appears in FNA Volume 27. Treatment on page 195.
Revision as of 21:51, 16 December 2019 by FNA>Volume Importer

Plants to 4.5 mm. Stems to 3 mm, branching near base. Leaves to 2 × 0.6 mm, ovate-lanceolate, acuminate, margins plane, serrulate in distal 1/3; costa extending 1/2–2/3 of the leaf length, occasionally slightly forked at apex; proximal cells 75–180 × 35–60 µm, distal cells 45–115 × 15–50 µm, marginal cells not differentiated. Calyptra entire at base, often with a single slit extending toward apex. Spores 27–42 µm.


Phenology: Capsules mature Jan–Apr.
Habitat: Mineral soil (mudflats) in lake banks
Elevation: low elevations

Distribution

V27 263-distribution-map.gif

Calif., Asia (China, Japan), Pacific Islands (New Zealand), Australia.

Discussion

Physcomitrella readeri is distinguished from the sympatric P. patens mainly by its shorter costa. The size of the rostrum has also been given taxonomic significance, but capsules of P. patens may also bear an apiculum reaching 0.2 mm. Similarly, the forked costa has been considered diagnostic of P. readeri, but this feature is not constant. The status of P. readeri has been repeatedly debated, but the geographic restriction of plants with short costae to a circum-Pacific range may justify taxonomic recognition. Physcomitrella readeri grows with P. patens in two localities in California.

Selected References

None.

Lower Taxa

None.
... more about "Physcomitrella readeri"
Bernard Goffinet +
(Müller Hal.) I. G. Stone & G. A. M. Scott +
Ephemerella readeri +
Calif. +, Asia (China +, Japan) +, Pacific Islands (New Zealand) +  and Australia. +
low elevations +
Mineral soil (mudflats) in lake banks +
Capsules mature Jan–Apr. +
Physcomitrella californica +, Physcomitrella patens subsp. californica +  and Physcomitrella patens subsp. readeri +
Physcomitrella readeri +
Physcomitrella +
species +