Phyllospadix torreyi / P. scouleri Silvetia compressa / S. deliquescens
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Hesperophycus californicus Silva (Previously known as Hesperophycus harveyanus (Decne) S. & G.)
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General Description (from Abbott and Hollenberg 1976 and Kendall et al. 2002): |
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Olive green to brown; perennial thallus; dichotomously branched but often appearing irregularly branched due to axis breakage; flattened with midribs in terminal thallus portions; tips of branches swollen when reproductive to produce oval receptacles, which accumulate gas; thalli 10-40 cm tall |
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Hesperophycus harveyanus branch tips |
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Habitat and Range (from Abbot and Hollenberg 1976): |
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Locally abundant to infrequent in upper intertidal, usually at higher tidal levels but sometimes mixed with Fucus on rocks in central California; In southern California, Hesperophycus characteristically occurs at tidal elevations immediately above Silvetia, replacing Fucus south of Pt. Conception; Santa Cruz, California to Is. San Benito, Baja California |
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Tufts of white hairs along midrib |
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Biology: |
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Hesperophycus is a fairly common fucoid alga along the central coast of California, found in the upper-mid tidal regions sometimes mixed with Silvetia or Fucus (Raimondi et al. 1999). Hesperophycus can usually be distinguished from Fucus by its narrower fronds and closely spaced tiny tufts of white hairs that grow in two parallel rows on either side of the mid-rib. Hesperophycus is particularly susceptible to oiling (Dawson and Foster 1982), and is believed to have declined in abundance along the southern California mainland. |
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Hesperophycus harveyanus |
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Hesperophycus harveyanus (top view) |
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Hesperophycus harveyanus branch tips |
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Can be confused with: Fucus gardneri, Pelvetiopsis limitata, and Silvetia compressa. In California, Fucus has broader fronds and lacks closely spaced white hairs along the midrib. Fronds of Silvetia and Pelvetiopsis lack a midrib. |
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Fucus gardneri |
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Fucus gardneri |
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References: |
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Abbott IA and Hollenberg GJ (1976) Marine algae of California. Stanford Univ Press, Stanford, CA Dawson EY and Foster MS (1982) Seashore plants of California. University of California Press, Los Angeles, California Kendall A, Kusic K, Maloney E, Williams M (2002) List of species to be discussed at the 2002 MMS Taxonomic Workshop Raimondi PT, Ambrose RF, Engle JM, Murray SN, Wilson M (1999) Monitoring of rocky intertidal resources along the central and southern California mainland. 3-Year Report for San Luis Obispo, Santa Barbara, and Orange Counties (Fall 1995-Spring 1998). OCS Study, MMS 99-0032, U.S. Minerals Management Service, Pacific OCS Region |
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Updated: 12/9/2004 |
