abatement - the state of gradually lessening a noxious weed’s hold on a particular area through control techniques

abiotic - the non-living elements in an ecosystem

adaptation - changes an organism makes to adapt to a different or changing nvironment so it can reproduce and survive

aggressive - vigorous, fast-growing

alkaline - having the properties of or containing an alkali (an acid neutralizing chemical substance); Alkaline substances have a pH greater than 7.0.

allelopathy - the process through which some weeds out-compete other species by poisoning the soil with a chemical that inhibits the growth of other plants

alternate - leaf arrangement in which each leaf is attached at a different level on the stem

angiosperm - a flowering plant

annual - a plant that flowers, produces seed, and dies in one growing season

anther - the head at the top of the filament where pollen forms

basal - leaves that occur at ground level

basal rosette - formed when there are many basal leaves

baseline data - information used as a reference with which to compare future observations or results

biennial - a plant that lives for two years and produces flowers and fruit in the second year

bilaterally symmetrical (irregular) - when a flower’s petals are divisible into two equal parts only along one line through the center

binomial nomenclature - the naming of all living things according to a hierarchy of shared characteristics; system developed by Swedish botanist Carolas Linnaeus

biodiversity - the range and abundance of organisms present in a given ecological community or system

biological control - controlling weeds through the introduction of a host-specific agent

biotic - the living elements in an ecosystem

blade - the flat part of a leaf; to physically scrape an area with a blade to remove weeds

bud - outgrowth on a stem or branch consisting of a shortened stem and immature leaves or flowers, often enclosed by protective scales

calyx - the outermost part of a flower; comprised of the sepals

cambium - tissue that forms the living part the stem; where cell division takes place in the stem

chemical - a substance used in or produced by the process of chemistry that has a defined atomic or molecular structure that results from, or takes part in, reactions involving changes in its structure, composition, and properties

chemical control - the use of chemicals (herbicides) to control weeds

chlorophyll - a green-colored chemical that converts the sun’s energy to food through the process of photosynthesis

chloroplasts - sacs in plant cells that contain chlorophyll

classification - the categorization of organisms into defined groups on the basis of identified characteristics

common name - the name organisms are usually called; can vary from region to region

community - all the plants and animals that live in the same area and interact with one another

competition - the struggle between organisms of the same or different species for limited resources such as food or light

composite - a flower consisting of tiny flowers forming a button-like center, with other tiny flowers forming at the rays; example: sunflower

contamination - to make something, such as soil, unfit for use as a result of contact with polluting or harmful substances

contour - the outline of a shape

contour line - lines on a map joining points that are at the same elevation

corolla - petals of a flower collectively, forming a ring around the reproductive organs and surrounded by an outer ring of sepals

corymb - a flat flower head consisting of flowers whose stalks grow from different points on the flower stem but reach approximately the same height

cotyledon - seed leaves within the seed

cultural control - controlling weeds through the use of tilling, planting competitive vegetation, fertilizing, implementing crop rotations, or managed livestock grazing

cycle - a sequence of events that is repeated again and again

declination - the angle between the direction of true north and magnetic north

dichotomous key - method of classifying organisms by choosing between two characteristics

dicotyledon - a flowering plant that produces two seed leaves when it germinates and whose subsequent leaves have a network of veins

dispersal - the natural distribution of plant seeds over a wide area by various methods

dormant - in an inactive state, when growth and development slow or cease, in order to survive adverse environmental conditions

dynamic equilibrium - balance that is maintained despite constantly changing elements

easting - east direction; the first number in a UTM coordinate

ecosystem - composed of all the biotic and abiotic things in a particular area that interact with each other

embryo - a plant in its earliest stages of development; in seed-bearing plants, the embryo is contained within the seed

endosperm - stored food within a seed

eradication - the process of destroying or getting rid of something completely so that it can never recur or return

evapotranspiration - the process of returning moisture to the air through both vaporation from the soil and transpiration by plants

exotic - having originated in another country

exponential growth - rapidly becoming greater in size

filament - the stalk-like part of the stamen

food chain - a hierarchy of different living things, each of which feeds on the one below

food web - interconnected food chains

forage - food for animals, especially crops grown to feed horses, cattle, and other livestock

geographical information system (GIS) - a broad title given to any process related to the creation or use of digital maps; a map with a connected database

germination - the process of growing from a seed or spore into a new plant

global positioning system (GPS) - technology that uses receivers that are in communication with orbiting satellites to determine accurate coordinates

glucose - a sugar produced by plants through photosynthesis

habitat - the natural conditions and environment in which a plant or animal lives

hectare - a metric unit of measurement equal to 100 acres or 10,000 square meters

herbicide - a chemical preparation designed to kill or inhibit the growth of plants, especially weeds

herbivore - an animal that feeds primarily on plants

high-risk area - any area that gets heavy use, such as roadsides, trailheads and trails, campgrounds, picnic areas, boat launches, airstrips, rest areas, and scenic overlooks

historic vs. current trends - how the overall weed picture is changing

host-specific agent - method of biological control that targets a particular host

inadvertent - done unintentionally or without thinking

index contour - the thicker contour lines on a topographic map; usually have a number that indicates the elevation along the line

infestation - the state of overrunning a place or site in large numbers and becoming threatening, harmful, or unpleasant

inhibit - to stop something from continuing or developing

Integrated Weed Management (IWM) - the use of chemical, mechanical, cultural, and biological control methods to manage weeds

integrity - maintenance of the functional attributes characteristic of a locale, including normal variability

intentional - done on purpose, not by accident

internode - the distance between nodes introduced – to place or establish an ndividual or species of plant or animal in a new habitat or environment

invasive - growing aggressively in an area and stifling the growth of preexisting plants

lamina - the blade or flat part of a leaf

lanceolate - a blade shaped like the tip of a lance

lateral - a bud in a leaf axil

latitude - angular distance (in degrees, minutes, and seconds) of a point on the earth’s surface north or south of the equator

leaf axil - the angle between the stem and the leaf stalk

legend - table or chart on a map that explains symbols used on the map

longitude - angular distance (in degrees, minutes, and seconds) of a point on the earth’s surface east or west of Greenwich, England

maturation - the process of becoming mature, ripe,or more developed

mechanical control - pulling weeds by hand; removing them with weedeaters, chainsaws, or mowing; or using fire to control weeds

meristematic zone - composed of the root cap and the zone of cell division

midrib - the thick central vein that runs from the base of a leaf to its apex

minerals - inorganic substances that must be ingested by animals or plants to remain healthy

monitor - to watch over a site to check the status of weeds at the site

monocotyledon - a flowering plant that has a single leaf in the seed and floral parts in multiples of three

monoculture - the practice of growing a single crop plant in a field or a larger area; a crop plant that is the only one grown in a field

native plants - plants that have evolved in a particular habitat over time

niche - the role of an organism within its natural environment that determines its relations with other organisms and ensures its survival

node - composed of the leaf axil and bud

non-native plants - plants that have been introduced, intentionally or unintentionally, into a habitat

northing - north direction; the second number in a UTM coordinate

noxious - harmful to animals, humans, and other organisms

nutrients - substances that provide nourishment, such as the minerals a plant takes from the soil that keep it healthy and help it grow

observation - the careful watching of something; paying attention; recording something that is happening

opposite - leaf arrangement in which two leaves are attached at one level but on different sides of the stem

origin - the source from which something from develops or arises

ornamental - a plant that serves as decoration rather than having any practical purpose

out-compete - to win the struggle with other organisms for limited resources, such as food or light ovary - where seeds develop at the base of a flower

ovate - a blade shaped like an egg, but with a pointed tip

palmately compound - leaflets attached at the end of a stalk, spreading like fingers on a hand

palmate veining - veins attached at one place, spreading like fingers on a hand

parallel veining - veins that run alongside each other and never intersect

parasitic - living in or on another host organism, usually causing it harm

perennial - a plant that lives for more than two growing seasons

perianth - composed of the calyx and corolla

petal - one of the showy colored parts that form the outer part of a flower

petiole - leaf stalk

phenology - the study of regularly recurring biological phenomena such as animal migrations or plant budding, especially as influenced by climatic conditions

phloem - a tube that carries food from the leaves to the roots

photosynthesis - process through which plants use sunlight, carbon dioxide, and water to make glucose and oxygen

physiological - relating to the way that living things function, rather than to their shape or structure

pinnately compound - leaflets arranged around a central stalk

pinnate veining - veins arranged around a central stalk (petiole)

pistil - the female reproductive part of a flower, composed of the ovary, style, and stigma

plumule - the rudimentary primary shoot of a plant embryo

pollination - the process of transferring pollen from the anther to the stigma to fertilize a plant

predation - the relationship between two groups of organisms in which one species hunts, kills, and eats the other

propagation - the reproduction of a plant or animal

propagule - a part of a plant, such as a bud, that becomes detached from the rest and forms a new organism

protocol - when conducting a weed inventory, the specific procedure to follow

quad - prefix meaning “four”

qualitative assessment - evaluation based on the quality or character of something rather than its size or quantity

raceme - a flower cluster in which the flowers are borne on short stalks along a long main stem

radially symmetrical (regular) - when a flower’s petals radiate in a wheel-like fashion

radicle - the part of a plant embryo that forms the root of the young plant

range - a large area of open land on which animals can graze

rangeland - land on which indigenous vegetation (climax or natural potential) is predominantly grasses, grass-like plants, forbs, or shrubs and is managed as a natural ecosystem; includes natural grasslands, savannahs, shrublands, many deserts, tundra, alpine communities, marshes, and wet meadows

rangeland health - the degree to which the integrity of the soil and ecological processes of rangeland ecosystems are maintained

relief - the difference in elevation between two points on a map

respiration - the process through which plants break down glucose to make energy; the reverse of photosynthesis

revegetate - to provide eroded or otherwise barren land with new plant life

rhizomes - thick underground horizontal stems that produce roots and have shoots that develop into new plants

scarify - to break the outer cover of hard seeds to aid germination

scientific name - the name an organism is given by the scientific community; made of two words, usually of Latin or Greek origin, the first of which lists the organism’s genus and the second of which lists its species

seed - the body produced by reproduction in most plants that contains the embryo and produces a new individual

seedbank - comprised of seeds a plant produces for reproduction in the future

sepals - individual parts of the calyx

sequence - the order in which things are arranged, actions are carried out, or events happen

simple - a leaf that is not divided, either totally or partially, into separate segments

smooth leaf margin - edge of a leaf that is not toothed or lobed

solitary - a flower that grows singly rather than as a cluster

species - a subdivision of a genus considered as a basic biological classification and containing individuals that resemble one another and that may interbreed

spike - a long cluster of flowers attached directly to a stem, with the newest flowers at the tip

stamen - the male reproductive organ of a flower, composed of the anther and the filament that holds the anther

stigma - the sticky top of the style that collects pollen

stomata - ventilation holes in a leaf that take in carbon dioxide and release oxygen

stratification - to store seeds in chilled, moist sand, peat moss, or other material to induce germination or preserve the seeds

style - stem-like extension of the ovary through which a pollen tube grows down into the ovary carrying the pollen necessary for fertilization

succession - the series of changes that create a fullfledged plant and animal community

survival - staying alive; continuation of life or existence

terminal - a bud at the tip of a stem

threshold - a transition boundary that an ecosystem crosses resulting in a new stable state that is not easily reversed without significant input of resources

township - a six square-mile area of land; basic unit of the Public Land System Survey

toxin - a poison produced by a living organism, causing disease

transect - a strip of ground along which ecological measurements are made at regular intervals

transpiration - the process of evaporation from a plant’s leaves

umbel - a flower cluster that has a number of branches all attached at one point

unintentional - not on purpose

Universal Transverse Mercator (UTM) - a grid pattern that is part of an international reference system for pinpointing locations on the earth

vein - a distinct strand of tissue in a leaf that contains the sap-conducting vessels

viable - able to grow or develop normally

vigorous - extremely strong and active; energetic

weed - any plant out of place, unwanted where it is growing, difficult to get rid of, with an ability to spread

weed inventory - tool that enables weed managers to collect data about plants in an area