Ephemerum serratum (Hedwig) Hampe
Ephemerum serratum is a minute, stemless, ephemeral moss, which appears shortly after the first winter rains (here in SoCal) on bare patches of disturbed soil in grasslands. The narrow, lance-like leaves (1.0-1.7 mm long) have a serrated edge and no mid-rib, and loosely surround the tiny spherical sporophyte capsule. The plants are often found amongst other slightly larger ephemeral moss species such as Pleuridium acuminatum and Acaulon muticum, but can also form small uniform patches where one can see more clearly the persistent protonema from which they arise.
Scroll down for more photos (click to enlarge) and descriptions of habitat, plants, leaves, sporophytes, distribution map, name origin, and similar species.
Habitat: Ephemerum serratum grows on disturbed soil in grasslands, in full sun or partial shade.
Habit: Ephemerum serratum plants are minute and stemless, consisting of a few narrow leaves surrounding an essentially sessile, round sporophyte capsule, which turns from green to chestnut brown upon maturation. Dry plants look quite similar to moist plants, with leaves still outstretched in open rosettes. In contrast to most moss species, the protonema from which the plants develop is persistent, and can be seen as tiny green threads between the plants. Ephemerum serratum can be found interspersed amongst slightly larger ephemeral mosses but can also form fairly uniform patches several centimeters wide.
Persistent Protonema: One of the hallmark characters of Ephemerum serratum is that the protonema persists generally until the sporophytes mature or even thereafter, in contrast to the very transient existence of the protonema of most moss species. Note that the protonema can be quite prominent, but can also be not so readily apparent.
Plants: Individual Ephemerum serratum plants are minute (less than 2 mm high) and essentially stemless, consisting of just a handful of long, narrow leaves loosely surrounding the sporophyte.
Leaves: Ephemerum serratum leaves are 1.0-1.7 mm long, narrow, lance-shaped with serrated margins and no midrib.
Sporophytes: Ephemerum serratum sporophytes consist of a spherical to ovoid capsule with a distinct nipple-like apiculus, atop a very short stem (seta). Capsules are cleistocarpous, lacking an operculum and simply degrading to release mature spores.
Distribution: Ephemerum serratum is found in North America and Europe.
Bryophytes of Santa Barbara 