© Ken-ichi Ueda, some rights reserved (CC-BY) · iNaturalist
Calasterella spp.
Mediterranean-climate regions including western North America
Native to North America
SunFull Shade – Part Shade
WaterHigh
Overview
Calasterella spp. is a genus of thallose liverworts in the family Aytoniaceae, represented mainly by C. californica, a small non-vascular plant of seasonally moist, shaded soil and rock. The plant body is a flat, ribbon-like green thallus a few millimetres wide that branches and presses close to the ground, lacking true roots, stems, or leaves. It anchors by thread-like rhizoids on the underside and absorbs water directly over its surface. Reproduction is by spores rather than flowers or seeds: stalked, star-shaped receptacles rise from the thallus and release spores, and the plant also spreads as fragments of the thallus. Calasterella spp. grows in regions with wet winters and dry summers, appearing on bare earth, banks, and rock crevices during the cool, moist season and shrivelling as conditions dry. It needs shade, a moist surface during growth, and a stable, low-competition substrate. As a small ground-hugging liverwort it is of botanical and habitat interest rather than a cultivated garden plant.
Native Range
Calasterella spp. occurs in areas with a Mediterranean-type climate of wet winters and dry summers, including western North America and parts of the Mediterranean region. It grows on bare soil, earth banks, and rock crevices in shaded, seasonally moist sites.Suggested Uses
Of interest mainly in botanical study, bryophyte collections, and habitat restoration rather than ornamental gardens. Where grown, it is kept on shaded soil or rock that stays moist through the cool season. It contributes to early soil cover on bare ground in suitable climates.How to Identify
Growing Conditions
Sun Requirements
Tolerates up to 3 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs