Bryophytes of Santa Barbara

Stegonia hyalinotricha (Cardot & Thériot) R. H. Zander

Stegonia hyalinotricha is a tiny (2 mm), budlike, ephemeral moss, that grows in small clusters on exposed soil, amongst grasses, herbs or shrubs. Its deeply concave leaves have long white hairlike tips (hyaline awns) and surround the sporophyte completely. Sporophytes consist of a slightly oblong capsule with a nipple-like apiculus, atop a slender, short seta. The capsule becomes a shiny, deep chestnut brown when mature, and is cleistocarpous, simply decaying to release the spores.

Scroll down for more photos (click to enlarge) and descriptions of habitat, plants, leaves, sporophytes, spores, distribution map, name origin, and similar species.

Stegonia hyalinotricha — Stegonia hyalinotricha CC BY-NC Amanda Heinrich

Habitat: Stegonia hyalinotricha grows on exposed soil amongst grasses, herbs and shrubs and other mosses.

Stegonia hyalinotricha — Stegonia hyalinotricha, just left of penny, on exposed soil amongst grasses, weeds and other mosses, in early February. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha — Stegonia hyalinotricha, just left of penny, on exposed soil amongst grasses, weeds and other mosses, in early March. CC BY-NC Amanda Heinrich

Habit: Stegonia hyalinotricha grows in small clusters, scattered or crowded, often in the company of other ephemeral and small mosses.

Stegonia hyalinotricha — Stegonia hyalinotricha cluster of budlike plants, still green in early February. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha — Stegonia hyalinotricha cluster of budlike plants, leaves turning brown, light brown ripening sporophytes peeking through, in early March. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha — Stegonia hyalinotricha in early April, leaves decaying, fully mature deep brown sporophytes revealed. CC BY-NC Amanda Heinrich

Plants: Stegonia hyalinotricha plants are tiny, up to 2 mm, and budlike, lacking a stem, resembling miniature onions, with their leaves tightly enveloping the round sporophyte,

Stegonia hyalinotricha — Two dry Stegonia hyalinotricha plants, stemless and budlike, sporophyte enveloped by concave leaves. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha — Two Stegonia hyalinotricha plants moistened, sporophytes visible through leaves. CC BY-NC Amanda Heinrich

Leaves: Stegonia hyalinotricha leaves are ovate and deeply concave with long hyaline awns, which are often slightly wavy or bent (flexuose). The margins of the leaf tips may be somewhat scalloped (crenulate), and the cells near the base of the leaf are long and rectangular.

Stegonia hyalinotricha leaf — Stegonia hyalinotricha leaf, 100x. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha leaf awns — Stegonia hyalinotricha flexuose hyaline awns, 100x. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha leaf tip — Stegonia hyalinotricha scalloped (crenulate) leaf tip, 400x. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha leaf base — Stegonia hyalinotricha long rectangular cells at leaf base, 400x. CC BY-NC Amanda Heinrich

Sporophytes: Stegonia hyalinotricha sporophytes consist of a slightly oblong capsule with a cute little nipple-like apiculus, all atop a tiny slender stalk (seta). The sporophyte is hidden within the clasping concave leaves until they begin to decay. The deep chestnut brown capsule then erodes to release the mature spores within.

Stegonia hyalinotricha sporophyte — Stegonia hyalinotricha sporophyte, oblong chestnut brown capsule with apiculus, atop slender seta. CC BY-NC Amanda Heinrich

Stegonia hyalinotricha spores — Stegonia hyalinotricha spores in early March, 400x. CC BY-NC Amanda Heinrich

Distribution: Stegonia hyalinotricha is found in California, into Baja California and perhaps into Arizona.

Stegonia hyalinotricha distribution — Stegonia hyalinotricha collections. Map generated by google maps using data from the Consortium of Bryophyte Herbaria of accessioned collections from herbaria.

Similar Species in Santa Barbara County

Phascum cuspidatum/Tortula acaulon, another ephemeral moss with long hyaline awns growing in similar habitat, is slightly larger, and less budlike, with longer, flatter leaves.

Acaulon muticum, another ephemeral moss growing in similar habitat, is also budlike with a fully enclosed sporophyte, but it lacks long hyaline awns.

Name: The genus name Stegonia is derived from the Greek word stego, which means, to cover closely, a reference to the leaves surrounding the sporophyte. The species epithet hyalinotricha, refers to the translucent (hyaline) hairlike (tricha, from the Greek thrix for hair) awn at the leaf tips.

References and Further Reading

Stegonia hyalinotricha, (Cardot & Thériot) R. H. Zander, Flora of North America Vol. 27, www.efloras.org new layout

Stegonia hyalinotricha, (Cardot & Thériot) R. H. Zander, Flora of North America Vol. 27, www.efloras.org original text

Contributions toward a Bryoflora of California II. A Key to the Mosses, Daniel H. Norris and James R. Shevock, Madrono 51(2): 133-269. 2004. Available for purchase here.

California Mosses, Bill and Nancy Malcolm, Jim Shevock and Dan Norris. Available for purchase from the California Native Plant Society here.