Ptilidium californicum
Encyclopedia
Ptilidium californicum is a rare
liverwort
of the Western U.S.
s dioicous, small but medium-sized for a liverwort, from golden-green to golden, but more typically reddish-brown, or dilute purplish-red, or coppery red, resembling a dense fuzzy mat, occurring in small or large patches. Shoots less than 1½ mm wide. Leaves incubous (decurrent on the dorsal stem surface), deeply bilobed; each lobe divided 1-3 times, elongated, narrowly lanceolate, deeply divided; lobe margins entire, with 1 or 2 long, slender, cilia-like projections along the lobes margins and at lobe apices; leaves so closely overlapping that only a mass of ciliate projections is visible under a hand lens. Underleaves prominent, wider than the stem but about or less than half the size of the leaves, 2-3 clefted, margins ciliate (even more finely divided into slender projections). Perianths plicate and narrowed to a ciliate mouth; frequent. Sporophyte
s abundant from May to August.
and Japan
, but recent literature calls it an endemic of the west coast of North America, ranging from south-eastern Alaska
to northern California
.
This plant has a narrow environmental specificity: it is found in (and serves as an indicator species of) old-growth forest. It is typically epiphytic on bark at the base of standing mature to old-growth trees (Abies concolor, A. magnifica, and Pseudotsuga menziesii) or recently fallen logs; rarely on other organic substrates such as decaying logs and stumps, or humus covering boulders. At the southern end of its range (Oregon
and California) this species is distinctly restricted to middle elevation forest
s. Its elevational range is from 1,275 ft. to 5,725 ft.
The fire ecology
of this plant is not known; however, fires in old-growth habitat might negatively affect P. californicum because of smoke, or from excessively opening the canopy. Severe fires that destroy old-growth trees would likely extirpate populations.
Pacific Southwest Region Sensitive Species.
NatureServe
California State Rank: S3; Global Rank: G4
The survival of Ptilidium californicum in the southern end of its range (i.e., northern California) depends upon the protection of the known sites as dispersal sources. The major threat facing P. californicum is loss of populations due to management activities that directly or indirectly impact the habitat or populations by disrupting stand conditions necessary for its survival. These include treatments such as: removal of colonized substrate, stand treatments that result in changes in microclimatic conditions or forest structure, or harvest of special forest products that may include individuals of this taxon. Spray paint used to mark 'leave,' 'take,' and 'wildlife' trees within project areas severely impact on this species. Liverwort
diversity and abundance are strongly affected by forest age, and both components are much greater in old-growth forests. Therefore, the loss of old-growth habitats poses another threat to this species.
Rare species
A rare species is a group of organisms that are very uncommon or scarce. This designation may be applied to either a plant or animal taxon, and may be distinct from the term "endangered" or "threatened species" but not "extinct"....
liverwort
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
of the Western U.S.
Technical description
PlantPlant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s dioicous, small but medium-sized for a liverwort, from golden-green to golden, but more typically reddish-brown, or dilute purplish-red, or coppery red, resembling a dense fuzzy mat, occurring in small or large patches. Shoots less than 1½ mm wide. Leaves incubous (decurrent on the dorsal stem surface), deeply bilobed; each lobe divided 1-3 times, elongated, narrowly lanceolate, deeply divided; lobe margins entire, with 1 or 2 long, slender, cilia-like projections along the lobes margins and at lobe apices; leaves so closely overlapping that only a mass of ciliate projections is visible under a hand lens. Underleaves prominent, wider than the stem but about or less than half the size of the leaves, 2-3 clefted, margins ciliate (even more finely divided into slender projections). Perianths plicate and narrowed to a ciliate mouth; frequent. Sporophyte
Sporophyte
All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or algae that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants...
s abundant from May to August.
Distribution, habitat, and ecology
In the past, this plant has been reported from RussiaRussia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, but recent literature calls it an endemic of the west coast of North America, ranging from south-eastern Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
to northern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
This plant has a narrow environmental specificity: it is found in (and serves as an indicator species of) old-growth forest. It is typically epiphytic on bark at the base of standing mature to old-growth trees (Abies concolor, A. magnifica, and Pseudotsuga menziesii) or recently fallen logs; rarely on other organic substrates such as decaying logs and stumps, or humus covering boulders. At the southern end of its range (Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and California) this species is distinctly restricted to middle elevation forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s. Its elevational range is from 1,275 ft. to 5,725 ft.
The fire ecology
Fire ecology
Fire ecology is concerned with the processes linking the natural incidence of fire in an ecosystem and the ecological effects of this fire. Many ecosystems, such as the North American prairie and chaparral ecosystems, and the South African savanna, have evolved with fire as a natural and necessary...
of this plant is not known; however, fires in old-growth habitat might negatively affect P. californicum because of smoke, or from excessively opening the canopy. Severe fires that destroy old-growth trees would likely extirpate populations.
Conservation status and threats
U.S. Forest ServiceUnited States Forest Service
The United States Forest Service is an agency of the United States Department of Agriculture that administers the nation's 155 national forests and 20 national grasslands, which encompass...
Pacific Southwest Region Sensitive Species.
NatureServe
NatureServe
NatureServe is a non-profit conservation organization whose mission is to provide the scientific basis for effective conservation action. NatureServe and its network of natural heritage programs are the leading source for information about rare and endangered species and threatened ecosystems in...
California State Rank: S3; Global Rank: G4
The survival of Ptilidium californicum in the southern end of its range (i.e., northern California) depends upon the protection of the known sites as dispersal sources. The major threat facing P. californicum is loss of populations due to management activities that directly or indirectly impact the habitat or populations by disrupting stand conditions necessary for its survival. These include treatments such as: removal of colonized substrate, stand treatments that result in changes in microclimatic conditions or forest structure, or harvest of special forest products that may include individuals of this taxon. Spray paint used to mark 'leave,' 'take,' and 'wildlife' trees within project areas severely impact on this species. Liverwort
Marchantiophyta
The Marchantiophyta are a division of bryophyte plants commonly referred to as hepatics or liverworts. Like other bryophytes, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information....
diversity and abundance are strongly affected by forest age, and both components are much greater in old-growth forests. Therefore, the loss of old-growth habitats poses another threat to this species.