Antheridium (pl. antheridia): a structure that produces motile male gametes (sperm).
Ascoglossan: referring to the order Ascoglossa (=Sacoglossa), an order of sea slugs (Mollusca: Gastropoda: Opisthobranchia).
Bisexual: having both sexes.
Blade: a flattened, leaf-like part of the thallus.
Calcar: spur subtending a cystocarp.
Carpogonium (pl. carpogonia): the female sex structure in red algae.
Carpospore: a spore, usually diploid, produced in the carpogonium. In red algae, it grows into a free-living tetrasporophyte.
Cerata: dorsal appendages on some opisthobranch mollusks (sea slugs) that contain diverticula of the digestive gland. Serve
Chloroplast: a cell organelle specialized for photosynthesis, the production of carbohydrates from carbon dioxide, water in the
presence of light energy.
Coenocytic: referring to a multinucleate cell, the coenocyte, derived when the nucleus divides but the cytoplasm does not.
Conceptacle: a fertile cavity, often with a pore.
Cortex: tissue external to the medulla, often an outer covering, of a blade.
Cryptostomata: minute cavities in the outer cortex of Fucales containing hairs.
Cystocarp: a structure in the female gametophyte of red algae consisting of diploid carposporophyte surrounded by
gametophytic tissue. It may be a pigmented bump with or without an ostiole.
Dichotomous: branching in pairs.
Dioecious: bearing male and female reproductive structures on separate individuals.
Diploid: having a normal (double or 2n) set of chromosomes.
Discoid: disk shaped. Usually referring to the shape of holdfasts.
Distichous: arranged in two rows on opposite sides of an axis.
Distromatic: having two layers of cells.
Gametangium (pl. gametangia): a structure that produces gametes.
Euryhaline: able to withstand a wide range of salinities.
Eurythermal: able to withstand a wide range of temperatures.
Filamentous: a row of cells arranged end to end forming a hair-like thallus.
Gamete: a sexual cell, male or female (e.g., sperm and eggs).
Gametophyte: the haploid and sexual phase in the life history of an alga; produces gametes.
Haploid: having a single set of chromosomes - half the normal number (1n).
Herbivory: feeding on plants.
Holdfast: the structure that attaches the alga to its substratum.
Intercallary: occurring anywhere along the thallus except at the apex.
Intergeniculum (pl. intergenticula): a calcified segment between the uncalcified joints of coralline algae.
Isomorphic: having the same shape; looking alike.
Lanceolate: shaped like a lance; several times longer than wide.
Laminarin: a polysaccharide carbohydrate energy storage product in Laminaria.
Meristem: a region of rapidly dividing, undifferentiated cells; an area of growth.
Midrib: the middle rib of a blade.
Monoecious: bearing male and female reproductive structures on the same individual.
Monostromatic: having one layer of cells.
Oogonium: a female reproductive cell (gametangium) that produces one or more female gametes (eggs).
Ostiole: a pore.
Papilla (pl. papillae): small rounded or pimple-like projections on a surface
Pericentral: surrounding central axial cells.
Pinnate: having similar parts arrange on opposite sides of an axis, like a feather.
Plastid: a pigmented cell organelle (e.g., a chloroplast which contains chlorophyll).
Pneumatocyst: a gas bladder or float of brown algae.
Receptacle: the inflated tip of a branch that holds conceptacles (e.g. the swollen tip of Fucus).
Rhizoid: a unicellular or filamentous structure for attachment.
Rhizome: a horizontal, shoot-producing stem growing within the substrate.
Saxicolus: growing on rocks.
Spermatangium (pl. spermatangia): a cell in red algae that produces a single, nonflagellated, male gamete (the spermatium).
Spore: a motile or nonmotile, asexual reproductive structure.
Sporophyll: the part of the alga, usually a blade, which bears sporangia, the structure that produces spores.
Sporophyte: the diploid phase in the life history of the alga; produces spores.
Sorus (pl. sori): a cluster of reproductive structures.
Stipe: the stem-like part of the thallus between the holdfast and the blade(s).
Stolon: a runner growing out of the base of the alga capable of producing offshoots.
Substratum: the material (such as rock) on which the alga is growing (substrate).
Tetraspore: a spore, grouped in fours, produced by tetrasporophytes
Tetrasporophyte: a phase in the life history of red algae that produces tetraspores.
Tertiary: referring to a third stage.
Thallus: the body of the alga.
Uniseriate: having a single row of cells.
Utricle: the inflated part of Codium that contains plastids.
Vegetative: not associated with reproductive cells or sexual reproductive capacity.
Zygote: a fertilized egg cell.