SafePlants

Ephemerum: The Elusive Earth-Moss

The genus Ephemerum, commonly known as Earth-moss, encompasses a group of minute mosses often overlooked due to their small size and ephemeral nature. These tiny plants offer a fascinating glimpse into the diversity of the bryophyte world.

Taxonomy and Nomenclature

• Genus: Ephemerum Hampe, 1837
• Family: Ephemeraceae
• Rank: Genus, Species (e.g., Ephemerum cohaerens)
• Synonyms/Related Taxa:
  • Ephemerum serratum (Hedw.) Hampe
  • Ephemerum serratum var. minutissimum (Lindb.) Grout
  • Ephemerum spinulosum Bruch &amp Schimp ex Schimp
  • Ephemerum crassinervum Hampe, 1837
• Common Names:
  • Earth-moss
  • Serrate ephemerum moss
  • Strap-leaved earth-moss (Ephemerum recurvifolium)
  • Clustered earth-moss (Ephemerum cohaerens)
  • Texas ephemerum moss (Ephemerum crassinervium texanum)
  • Virginian ephemerum moss (Ephemerum virginianum)
• Taxon Version Keys:
  • Ephemerum recurvifolium: NHMSYS0000309833
  • Ephemerum cohaerens: NBNSYS0000036525

Considerations for Pets

• Some species of Ephemerum, such as Ephemerum spinulosum, have sharply-toothed leaves.

Distribution and Habitat

• Ephemerum mosses are found in various regions, including:
  • Europe (e.g., for Ephemerum spinulosum)
  • California (throughout low elevations)
  • Czechoslovakia
  • Dutch Rhine floodplain
  • Northern England, English Midlands, East Anglia, Wales, southeast England, central southern England
  • Franklin County, Ohio (Ephemerum cohaerens at Battelle Darby Metro Park)
• They often thrive in moist habitats where moss spores can germinate and filamentous protonema can grow.

Morphological Characteristics

• Ephemerum species are characterized as minute plants, sometimes reaching only up to 2 mm in height.
• Ephemerum crassinervum has leaves from 0.8 to 2.5 mm long that are very serrate.
• The shoots emerge from a persistent dark green or brownish protonema.
• As mosses, they are nonvascular plants.

Quirky Facts

• Ephemerum is probably the smallest moss in California.
• Cape pygmy moss (Ephemerum capensi) is so tiny it can be as small as a pencil dot.

Ecological Role

• Ephemerum has reduced and short-lived sporophytes with few stomata, in contrast to mosses like Oedipodium, which have elaborated stomata.
• They can be found growing with other mosses, such as Bryum warneum.

Further Information

• USDA resources may contain information on Ephemerum serratum.
• Taxonomic information on Ephemerum spinulosum can be found in the British Database of World Flora and Fauna.
• Encyclopedia of Life has information on Ephemerum within the Family Ephemeraceae.
• TSN 15846 is a taxonomic serial number associated with Ephemerum serratum.