UC specimens and range limits for Pseudolithoderma nigrum

• Blue markers: specimen records
• Yellow marker: type locality, if present
• Red markers: endpoints of range from literature

View map from the Consortium of Pacific Northwest Herbaria

Notes: Herbarium specimens are rare; most are in the Smithsonian National Herbarium. Vouchers from San Nicolas Island (in UC), Santa Catalina and San Clemente islands, Corona del Mar and Laguna Beach, Orange Co., False Bay, San Diego and La Jolla, San Diego Co., Punta Banda, Baja California and Salina Cruz, Oaxaca, Mexico.

Status: This species has not been studied with molecular methods. It should be compared with the type of the genus, P. fatiscens Svedelius, and P. roscoffensis Loiseux, for which rbcL, CO1, and LSU have been sequenced.

Habitat: Upper interidal, especially in shaded areas on barnacles and under Silvetia compressa and S. compressa subsp. deliquescens

Life History: Unilocs unknown; plurangia formed from October through March; initial culture studies suggested that these were asexual, and that there is no alternation of generations (Hollenberg 1969).

Search Sequences in GenBank

Pseudolithoderma Svedelius 1910

Thalli horizontally expanded, crustose, firmly adhering to substratum without rhizoids. Erect filaments firmly adjoined, sparsely branched, arising from relatively indistinct basal layer, this primarily 1 cell thick. Cells with several to many small, discoid chloroplasts, these lacking pyrenoids. Hair pits occasional. Unangia present in some species, terminal on erect filaments. Plurangia terminal on erect filaments, without sterile terminal cell.

Pseudolithoderma nigra Hollenb.

Hollenberg 1969: 297.

Thallus 2-10+ cm broad, nearly black, mostly 300-500 µm thick; growth lines inconspicuous or absent; cells of erect filaments 9-10 µm diam., mostly shorter than broad; unangia unknown and probably absent; plurangia in extensive irregular sori, mostly 30-50 µm long, 8-14 µm diam., composed of tiers of 4 cells, without sterile terminal cells; nearly colorless paraphysis-like cells scattered among plurangia.

Common, often forming extensive areas on rocks, upper intertidal in Pelvetia zone, Shell Beach (San Luis Obispo Co.), Channel Is., and Corona del Mar (Orange Co.; type locality), Calif., to Oaxaca, Mexico.

Excerpt from Abbott, I. A., & Hollenberg, G. J. (1976). Marine algae of California. Stanford University Press, Stanford, California. xii [xiii] + 827 pp., 701 figs.

Notes: Pseudolithoderm is neuter, requiring a neuter specific epithet.