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Wetland Plants and Plant Communities of Minnesota and Wisconsin

GLOSSARY


acid:
having more hydrogen ions than hydroxyl ions; a pH of less than 7.

aerobic:
a condition in which free molecular oxygen is present.

alien:
a non-native (introduced) species, which may or may not be naturalized.

alkaline:
basic, having more hydroxyl ions than hydrogen ions; a pH of greater than 7.

anaerobic:
a condition in which free molecular oxygen is absent.

annual:
a plant that completes its life cycle in one growing season, then dies.

auriculate:
having ear-shaped lobes at the base.

awn:
a bristle, often located in a terminal position on a specific plant part.

beak:
a relatively stout tip such as on a nutlet.

biennial:
a plant that completes its life cycle in two years, usually flowering and producing fruit the second year, and then dies.

calcareous:
limy, rich in calcium, usually in the form of calcium carbonates.

calciphile:
a plant species with a high tolerance of calcium.

callosites:
a hardened thickening of plant tissue.

calyx:
the frequently green outer series of floral leaves (or sometimes the only ones); the sepals collectively.

CFR:
Code of Federal Regulations.

clasping:
partly surrounding another organ at the base.

clonal:
forming clones.

clone:
a group of vegetatively produced, genetically identical individuals.

colonial:
forming colonies.

colony:
a group of individuals of the same species produced vegetatively or by seed, that may or may not be genetically identical.

community:
in reference to plants, an interacting assemblage of plant populations sharing a given habitat.

composite:
a member of the aster family (Compositae).

corolla:
the inner series of floral leaves, often showy; the petals collectively.

dbh:
diameter at breast height; a measure of tree diameter at 4.5 feet above the ground or root collar.

deciduous:
falling off, usually at a certain season, after completion of the normal function.

dichotomous:
forking into two directions of essentially equal branches.

disc:
in the aster family (Compositae), a group of tubular flowers located in the central part of the flower head.

dolomite:
in Minnesota and Wisconsin, a bedrock mineral consisting of calcium magnesium carbonate (CaMg(C03)2)

dominant:
a species that exerts a considerable influence on, or defines the character of, a community because of such factors as its number, coverage, or size.

ericaceous:
refers to members of the heath family (Ericaceae).

fen:
in a broad sense, wetlands that are predominately supported by groundwater discharge; fens can be segregated by soil chemistry, water chemistry, and vegetation, e.g., calcareous fens.

floret:
a small or reduced flower, such as that of grasses.

follicle:
a dry fruit that splits open along one seam.

forbs:
herbaceous plants, excluding the grasses, rushes and sedges; especially used to describe broad-leaved, flowering plants.

frond:
the leaf of ferns; also, the vegetative structure of duckweeds (Lemnaceae) that is not differentiated into stem and leaf.

genus:
the first part of the scientific name for an organism, always capitalized (plural, genera).

glabrous:
smooth.

glaucous:
covered with a pale, waxy coating or "bloom."

glume:
a specialized, scale-like leaf at the base of a grass spikelet.

graminoid:
grass-like plants including grasses, sedges and rushes.

growing season:
that portion of the year when soil temperatures at 19.7 inches below the surface exceed biologic zero (41 degrees F.). This can be approximated by the number of frost-free days (i.e., the period between the last frost of spring and first frost of autumn).

herb:
a herbaceous (non-woody) plant.

hispid:
having rigid hairs.

hybrid:
a cross-breed between two species.

hydrophyte:
a plant growing in water or on a substrate that at least periodically is deficient in oxygen due to excessive water content.

hypersaline:
extremely salty; very high concentration of dissolved salts.

inflorescence:
the entire flower cluster of a plant.

isodiametric:
having equal diameters.

keel:
a longitudinal ridge (like the keel of a boat).

leaflet:
one of the blades of a compound leaf.

lemma:
the lowermost scale-like leaves at the base of a grass floret.

lenticel:
a small dot on the bark of young trees or shrubs.

ligule:
in the grasses (Gramineae), a papery extension at the summit of a leaf sheath.

lip:
one part of a two-lipped (bilabiate) flower; in the orchids (Orchidaceae), the odd petal that is usually the lowest.

macroscopic:
visible without magnification.

mesic:
intermediate between dry and wet conditions; moderately moist.

mixosaline:
of intermediate salinity; somewhat salty.

monotype:
a plant community consisting of only one species.

muck:
a soil consisting of partially decomposed plant remains where the decomposition has progressed to a point where the contributing plant species cannot be identified; an organic soil as opposed to mineral soils.

native:
an indigenous species.

nerve:
a ridge or vein on a plant structure.

nonpersistent emergent:
an aquatic emergent plant whose upper portions (stems, leaves) die back at the end of the growing season (e.g., arrowhead).

nutlet:
a small dry fruit that does not split open along a seam or surface; as used herein, synonymous with achene.

ocrea:
a stipular, tube-shaped sheath that surrounds the stem just above the leaf base; a characteristic of the smartweed family (Polygonaceae).

oogonia:
eggs of algae.

ovary:
the lower, usually enlarged portion of the pistil, in which the seeds are produced.

peat:
a soil consisting of partially decomposed plant remains in which the contributing plant species can still be identified; an organic soil as opposed to mineral soils.

pedicel:
the stalk of a single flower.

perennial:
a plant species living three or more years.

perfect flower:
a flower having both pistils and stamens.

perigynium:
a flask-like papery structure that surrounds the ovary in Carex (plural, perigynia).

persistent emergent:
an aquatic emergent plant that remains standing through the winter and at least until the start of the next growing season (e.g., cattails).

petiole:
the stalk of a leaf.

pinnae:
one of the primary lateral divisions of a pinnately compound leaf.

pinnatifid:
a deeply lobed, pinnate-like pattern cut along a central axis; the inter-segmented clefts, however, do not reach the axis.

pioneer:
a plant species that characteristically first colonizes exposed soils.

pistil:
the seed producing organ of a flower, composed of an ovary, and one or more styles and stigmas.

pistillate:
having only pistils (lacking staminate (pollen-producing) organs).

pith:
the spongy central portion of stems and branches.

pubescent:
hairy.

punctate:
dotted.

rachis:
a main axis, such as that of a compound leaf.

ray:
in the aster family (Compositae), a strap-shaped marginal flower radiating from the flower head.

receptacle:
in the aster family (Compositae), an enlarged summit of the flower stalk to which the flowers are attached.

recurved:
curved backward.

revolute:
having the margins rolled backward.

rhizome:
an underground stem, usually growing horizontally.

rosette:
a dense, circular, clump of leaves.

saline:
salty; having a high concentration of dissolved salts.

samara:
a dry fruit, which does not split open along a seam, and has a well-developed wing.

scabrous:
rough.

scale:
a small, modified leaf subtending an individual flower, especially referring to sedges (Cyperaceae).

secund:
arranged along only one side of the axis.

sepal:
a single segment of the calyx, usually green.

sessile:
lacking a stalk.

spikelet:
a small spike with reduced flowers on a central axis; applied to the flower cluster (inflorescence) of grasses (Gramineae) and sedges (Cyperaceae).

sporangia:
a case or structure that contains spores.

spur:
a flower part that is a hollow, pointed projection.

stamen:
the male or pollen-producing organ of the flower.

staminate:
having only stamens (lacking pistillate (seed producing) organs).

stand:
a particular example of a plant community.

stigma:
the terminal portion of a pistil which is receptive to pollen.

stipe:
a stalk.

stipule:
an appendage at the base of a leaf.

stolon:
an above-ground, horizontal stem.

strigose:
having straight, stiff hairs that are flattened along a surface.

style:
the stalk-like portion of a pistil connecting the stigma and ovary.

tepal:
in a given plant, sepals and petals that strongly resemble each other.

thyrse:
an inflorescence resembling a compact panicle.

till:
unstratified and unsorted material deposited directly by a glacier.

tuber:
a starchy, enlarged portion of a rhizome or root.

tubercle:
a small enlargement or appendage, usually distinct in color or texture, as in the "cap" on the nutlet of spike-rushes.

unisexual:
having only stamens (staminate) or pistils (pistillate).

upland:
an area that does not have the hydrologic conditions necessary for the development of hydric (wetland) soils and establishment of wetland plant communities.

villous:
having long, soft hairs that are not matted.

wetlands:
areas saturated or inundated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.

whorl:
a group of three or more parts surrounding a node.

Inflorescence types

Leaf shapes

Leaf venation and leaf margins

Cross sections of a typical flower and typical composite flower

Cross sections of a typical grass spikelet and a perigynium (Carex)

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Menlo Park, CA [caww55]