asexual reproduction- expansion of the leaves, stems, roots, and rhizomes of the plant by cell division.

adventitious- developing in an irregular or unusual position especially in reference to buds and roots

alternate- leaves not opposite to each other but at regular intervals along a stem

annual- a plant that completes its life cycle in one year

antherida- male sexual part in algae

axis- angle usually formed by a leaf or petiole with the stem

axillary- in or associated with the axis

bract- modified leaf associated with, but not part of, a flower

bulbils- vegetative (asexual) bud produced at stem nodes in algae

calcareous- encrusted (covered) with calcium carbonate

cuticle- protective, waxy layer covering plant surfaces

dioecious- male and female flowers occurring on separate plants

entire- without teeth or divisions (refers to leaf margins)

eutrophic- containing a high concentration of nutrients; particularly nitrogen and phosphorous

fibrous- composed of or resembling fibers

filiform- thread-like

hydroid- highly branched, colonial group of invertebrate organisms, closely related to sea anemones

hypanthium- an enlarged or developed flower receptacle

inflorescence- the entire flower cluster

invertebrate- animal without a backbone, such as insects and worms

lanceolate- shaped like a lance or arrowhead

lateral- on the sides

linear- long and narrow with parallel sides

monoecious- male and female flowers occurring on the same plant

node- positions on upper stems, usually bearing leaves, or on lower stems, usually bearing roots

obovate- egg-shaped, with the broader end above the middle (refers to leaves).

opposite- leaves arranged directly across from one another along a stem

ovoid- solid, with an egg-shape

peduncle- flower stalk

perfect flower- having both stamens and pistils

perennial- a plant living more than two years

perianth- petals and sepals together

petals- inner leaves of a flower

petiole- the lower stalk of a leaf

pinnate- compound leaves arranged on both sides of a common axis, as in a feather

pistil- seed-bearing organ of a female flower

pistillate- containing pistils

pollen- reproductive grains contained in stamens (male)

ppt- parts per thousand (the units of measure for salinity)

rachis- main axis of a leaf or spike

rhizoids- slender, root-like organs

rhizome- lower horizontal stems either prostrate on sediment surface or buried; usually with roots and new shoots at stem nodes and curving upward at the ends

rosette- circular cluster of leaves or other structures

runners- branches off buried rhizomes; usually with tubers produced at the ends

sepals- the outer leaves of a flower

serrated- having sharp teeth (refers to leave margins)

sheath- enveloping lower parts of leaves

spathe- a large bract enclosing a flower or group of flowers

spike- a large group of flowers on an elongated axis

stamen- pollen-bearing (male) organ of a flower, composed of an anther at the end of a slender stalk (filament)

staminate- containing stamens

stipule- appendage at the base of a leaf or its petiole

stolon- prostrate (lying flat on the ground), slender aboveground stem producing new plants at nodes

stomata- opening on the epidermis of a leaf or stem through which water vapor moves out of the plant and carbon dioxide moves in

tendril- a slender, clasping, or twining outgrowth

terminal- at the tips or end

truncate- with the base or tip transversely straight as if cut off

tubers- vegetative (asexual) buds (buried in the sediment) usually forming at the end of runners; capable of remaining dormant before developing into new plants

turions- vegetative (asexual) buds usually formed in the leaf axils or stem tips; capable of remaining dormant before developing into new plants

undulated- having a wavy margin or surface

vegetative reproduction- see asexual reproduction

whorl- a circle of 3 or more branches, leaves or flower stalks arising from the same node