Algae Glossary

adventitious: Structures developing an unusual position.
alternate: Arranged singly at regular intervals on an axis, and alternating in orientation to the axis.
anastomose: Secondary joining of cells or branches.
apex: The point farthest away from the point of attachment.
apical: Located at the apex or tip.
axis: The longitudinal, central supporting structure.

blade: Flattened leaf-like plant part.
brackish: Somewhat salty; body of water that is off lower salinity than the ocean.
branch: Plant division subordinate to the main axis.
branching: Descriptive patterns of branches.

calcified: Containing large amount of calcium carbonate; chalky.
carpospore: Spore produced in a carposporangium, usually diploid.
carposporophyte: Multicellular phase in the life cycle of red algae resulting from the development of the zygote and terminated by carpospore production.
compressed: Flattened.
coralline: Calcareous red alga of the family Corallinaceae; erect or crustose plants; many shores in the tropics are dominated by coralline algal reefs rather than by coral (animal) reefs.
cortex: Outermost layer, cotical layer, of cells or tissue of a thallus; presence of cortex, thallus is said to be corticated.
cystocarp: See carposporophyte.

determinate: Axes or branches that stop growing at a predetermined length.
dichotomous: Branched or forked into two more or less equal divisions.
differentiated: Differences in structure and function of groups of cells due to increased specialization in an organism.

filamentous: Hairlike; having a single row of cells that can be joined laterally.
fluorescence: A kind of luminescence; emission of radiation in the form of light.
forcipate: Forked and incurved.
frond: Single and commonly leaflike erect part of the plant.

gametangium: pl. gametangia; A container in which gametes are produced.
gametophyte: Plant form or phase in life history that bears gametes. Alternate phase is the sporophyte (bears spores).
gelatinous: Jelly-like in texture.
growth: Increase in the size of an organism, by cell division or cell expansion.

habitat: The place or environment where a plant or animal naturally or normally lives and grows.
hair: Slender cell; an unbranched, usually nonpigmented filament; surface extension.
holdfast: Structure by which an alga is attached to the substratum. Larger than a rhizoid.

indigenous: Naturally occuring in the Hawaiian Islands and elsewhere.
intercalary: Occurring anywhere along the length of a structure except at apex.
internode: Segment of a thallus lying between two nodes or joints.
intertidal: Occurring between the levels of low and high tides; exposed at low tide.
irregular: No regular arrangement.
limu: The Hawaiian word for all water plants, including freshwater plants, lichens, mosses, and seaweed. In cmmon usage, it refers to the edible or useful algae.
lubricous: Slippery.

saxicolous: Growing on rock.
secund: Arranged to one side only.
sori: Group or cluster of reporductive organs not elevated above the surface.
spermatangium: pl. spermatangia; A cell producing a single male gamete with no flagella.
spine: A stiff, sharp-pointed structure.
spiral: Arranged singly at regular intervals, and rotating around the axis.
sporangium: pl. sporangia; Structure in which spores are formed.
stolon: Branch or runner growing out from the base of a parent plant and capable of forming offshoots.
sublittoral: At a depth below the lowest level of low tide.
substratum: pl. substrata. Surface or material on which an alga is growing.
subtidal: Occurring below the lowest level of low tide; never exposed.

tendril: Slender, twining organ used to grasp support for climbing.
terete: Cylindrical in cross-section.
tetrasporangium: pl. tetrasporangia; A haploid spore, usually the product of a meiotic division; borne in a sporangium (tetrasporangium).
thallus: pl. thalli; Plant body of an alga. Used to emphasize that algae do not have the structures of flowering plants, such as stems, leaves, and roots.
tide: the alternate rising and falling of the surface of the ocean and of water bodies connected with the ocean that occurs usually twice a day and is caused by the gravitational attraction of the sun and moon occurring unequally on different parts of the earth.
tidepool: Pool of water located above the level of low tide; experiences fluctuating temperature and salinity.
transparent: Fine enough to be seen through.
trichoblast: Simple or branched, usually colourless, hairlike filament.
trichotomous: Three-forked; branched into three more or less equal divisions.