Plocamiaceae

Plocamium sp., copyright Derek Keats.

Belongs within: Florideophycidae.

The Plocamiaceae is a family of red algae including the free-living Plocamium and its adelphoparasite Plocamiocolax.

Characters (from Womersley 1994): Thallus (of free-living species) erect, complanately branched, with alternating marginal series of 2–6 compressed lateral branches or ramuli, axes sympodially developed, base stoloniferous (or parasitic and pulvinate); structure uniaxial, with a central filament surrounded by a pseudoparenchymatous cortex. Sexual thalli dioecious; procarpic. Carpogonial branches 3-celled, borne on mid cortical cells, with the supporting cell acting as the auxiliary cell. Carposporophyte outwardly directed, with a basal fusion cell producing several gonimolobes with all except the basal cells forming carposporangia, enclosed in a dense cellular pericarp; cystocarps sessile or pedicellate on the upper ramuli of the series, non-ostiolate. Spermatangia developed from surface cortical cells on upper ramuli or on branched tufts in their axils. Tetrasporangia borne in simple or branched stichidia on the margins of upper ramuli or in branched axillary tufts. Life history triphasic with isomorphic gametophytes and tetrasporophytes.

Plocamiaceae [Plocamiales]
    |--Plocamiocolax pulvinata Setchell 1923 S57
    `--Plocamium HSA03
         |--P. abnorme Hooker & Harvey 1845 L27
         |--P. angustum Agardh 1841 L27
         |--P. brachiocarpum Kützing 1849 L27
         |--P. cartilagineum HSA03
         |--P. coccineum Lyngbye 1819 L27
         |--P. costatum Agardh 1841 L27
         |--P. cruciferum Hooker & Harvey 1855 L27
         |--P. dilatatum Agardh 1876 L27
         |--P. dispersum Hooker & Harvey 1855 L27
         |--P. hamatum NLS03
         |--P. leptophyllum Kützing 1849 L27
         |--P. mertensii G05
         |--P. oregonum Doty 1947 S57
         |--P. pacificum Kylin 1925 S57
         |--P. procerum Agardh 1841 L27
         |--P. rigidum Agardh 1851 L27
         |--P. telfairiae L27
         |--P. tenue Kylin 1925 S57
         `--P. violaceum Farlow 1877 S57

*Type species of generic name indicated

REFERENCES

[G05] Goldberg, N. A. 2005. Temporal variation in subtidal macroalgal assemblages at Black Island, Recherche Archipelago. Journal of the Royal Society of Western Australia 88 (2): 65–71.

[HSA03] Huisman, J. M., A. R. Sherwood & I. A. Abbott. 2003. Morphology, reproduction, and the 18S rRNA gene sequence of Pihiella liagoraciphila gen. et sp. nov. (Rhodophyta), the so-called ‘monosporangial discs’ associated with members of the Liagoraceae (Rhodophyta), and proposal of the Pihiellales ord. nov. Journal of Phycology 39: 978–987.

[L27] Laing, R. M. 1927. A reference list of New Zealand marine algae. Transactions and Proceedings of the New Zealand Institute 57: 126–185.

[NLS03] Nelson, T. A., D. J. Lee & B. C. Smith. 2003. Are “green tides” harmful algal blooms? Toxic properties of water-soluble extracts from two bloom-forming macroalgae, Ulva fenestrata and Ulvaria obscura (Ulvophyceae). Journal of Phycology 39: 874–879.

[S57] Scagel, R. F. 1957. An annotated list of the marine algae of British Columbia and northern Washington (including keys to genera). National Museum of Canada Bulletin 150: 1–289.