UC specimens and range limits for Codium johnstonei

• 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: Collected at Islas Coronados, Santa Catalina, Santa Cruz, and Anacapa islands; Redondo Beach, Los Angeles Co.

Status: The unique morphology of this species is readily distinguished; it has not been included in molecular studies of the genus.

Habitat: On cobble and reefs in the deep subtidal

Life History: Not investigated, but probably with a perennial diploid macroscopic thallus producing anisogametes, zygote developing into pancake-like stage from which gametophyte eventually arises.

Search Sequences in GenBank

Codium Stackhouse 1797

Thalli much branched, the branches compacted and forming erect or prostrate, noncalcareous spongy thallus of definite form, basally attached by rhizoids. Surface layer composed of palisade-like, photosynthetic, enlarged branch tips (utricles). Interior of thallus composed of slender, colorless, intertwined tubular branches. Thalli mostly dioecious; gametangia fusiform to cylindrical, borne laterally on utricles and sealed off at base by annular thickenings. Gametes biflagellate, anisogamous, formed following meiosis. Zygote developing directly into diploid plant.

Codium johnstonei Silva

Silva 1951: 94.

Mature plants dark green, erect, cylindrical to slightly compressed, unbranched, 15-20 mm diam., to 10 cm tall; utricles unbranched or with a few branches below, 70-110(140) µm diam., 2+ mm long, truncate or slightly rounded at apex; terminal wall of utricle to 65 µm thick, slightly laminate and slightly to markedly umbonate internally; utricular hairs infrequent.

Occasional, mostly saxicolous and subtidal (to 46 m), Santa Cruz I., Calif. (type locality), to Is. Coronados, Baja Calif.; in Calif., from Santa Cruz I., Redondo Beach, and Laguna Beach.

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: See Illustrations for drawings of utricles.