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Species Name: Bostrychia montagnei
Common Name: Sea Moss (collective term, not specific to this species)
Synonymy: None

    Kingdom Phylum/Division Class: Order: Family: Genus:
    Plantae Rhodophyta Rhodophyceae Ceramiales Rhodomelacedae Bostrychia

    Species Description

    The genus Bostrychia is a widespread Rhodophycean species, found from tropical to cool-temperate areas, but is most often associated with mangroves (Smith and Norris 1988). Eight species are known in the tropical and subtropical western Atlantic. Branches are bilateral and feathery in appearance, with curled tips. Lower branches have very few branchlets (Littler and Littler 1989). The color of B. montagnei is generally a dark purple to blackish that, when dry, becomes a pale yellow color. This species grows to 8 cm, but is generally shorter. It is usually found growing in tufts on the prop roots of mangroves in the sheltered upper intertidal zone, although it occasionally is found on rocks, pilings, and seawalls.

    The taxonomy of the genus Bostrychia is based almost solely on vegetative, rather than reproductive structures. This is primarily due to the fact that it is somewhat rare to collect male or female gametophytes in nature. However, reproductive structures are important taxonomic traits within this genus and can be used to assess the relationships between members of the genus. An examination of these structures is given in Smith and Norris (1988a; 1988b), who used the structural simplicity of reproductive tissues in this genus to support the idea that Bostrychia is indeed one of the more primitive genera in the Rhodomelaceae.


    Regional Occurrence

    B. montagnei is widely distributed throughout the tropics and subtropics, and is typically found in Florida, the Caribbean and along the west coast of Africa. It has limited distribution in cool-temperate zones.

    IRL Distribution

    In the Indian River Lagoon, B. montagnei occurs almost solely on the prop roots of the red mangrove, Rhizophora mangle. It has also been collected from the Florida Keys and along the east coast of central Florida.


    Age, Size, Lifespan

    Generally grows to less than 8 cm.


    B. montagnei is considered to be relatively abundant in Florida, though not always seen year-round. In the Indian River Lagoon, it is most prevalent in late summer and fall.


    Development of the cystocarp, a female reproductive structure which releases meiotic spores, appears to be developmentally regulated such that only a single cystocarp will mature per branch, despite the fact that as many as 20 procarps (precursors to the cystocarp) may initially be present (Smith and Norris 1988). Male thalli of this species produce spermatangia continuously over a fertile branch.


    No information is available at this time


    Trophic Mode



    B. montagnei is likely to compete with other epiphytic species which colonize mangrove prop roots.


    Most commonly found in the sheltered upper intertidal zone, though it can also utilize higher energy habitats.

    Associated Species

    In the Indian River Lagoon, B. montagnei is generally found growing on the prop roots of the red mangrove, Rhizophora mangle.


    No information is available at this time


    Littler DS, Littler MM, Bucher KE, Norris JN. 1989. Marine Plants of the Caribbean, a Field Guide from Florida to Brazil. Washington, DC: Smithsonian Institution Press.

    Smith C, Norris J. 1988a. Structure and occurrence of spermatangia in Caribbean Bostrychia montagnei Harvey and B. binderi Harvey (Rhodophyta, Ceramiales). Jpn J Phycol 36: 127-137.

    Smith C, Norris J. 1988b. Procarp structure in some Caribbean species of Bostrychia Montagne (Rhodophyta, Rhodomelaceae): an important systematic character. Atoll Res Bull 312: 1-15.

Report by: K. Hill, Smithsonian Marine Station
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Page last updated: July 25, 2001

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