Bishop Field Office

Glossary of Weed Terms


Photo of Musk Thistle FlowerPhoto of Purple loosestrife flowerPhoto of St. Johnswort flower


Glossary
alternateleaf structure not opposite on stem
annualcompleting the life cycle in one growing season
awneda slender bristle-like appendage usually at the end of a structure
basal

of or at the base

biennial

completing the life cycle in two growing seasons

bract a more or less modified leaf situated near a flower of inflorescence
creeping 

to grow along the ground or some structure

dioecious 

flowers unisexual, the male and female flowers on different plants

divided 

said of leaves; deeply lobed, the sinuses extending to the base of the leaf or midrib

entire

margins smooth without teeth or lobes

floret small flower, especially one in a dense cluster; a grass flower
flower 

seed producing structure of a plant

fruit 

ripened ovary and its structures that enclose it at maturity

glabrous

smooth, no hairs present

glandular bearing glands; glandular hairs with sticky substance at the end
glumes 

chaff-like bract; used for the two lower empty bracts of a grass spikelet

herbaceous

having the characteristic of a herb; leaf-like in color and texture

inflorescence

flowering part of a plant; generally used for flowering cluster

lanceolate

lance shaped; several times longer than wide with broadest toward the base and pointed at the apex

lateral 

born on the side of a structure or object

leaf 

flat thin part of a plant growing from the base or stem

linear 

narrow and flat with sides parallel as in a leaf

lobed 

bearing lobes; generally the sinuses are not half way to base of leaf or midrib as in oak leaves

monoculture

only one species present

monotypic

when referring to a vegetation community, consisting mostly of only one species of plant

oblong

two to four times longer than wide with the sides nearly parallel as in a leaf

oxalates a salt of oxalic acid; a poisonous acid found in some plants
perennial a plant whose life cycle extends for three or more years
persistent

remaining attached after like parts normally fall off

phyllarythe name of the bract on the head of a sunflower
pinnate compound leaf with the leaflets on two opposite sides of an elongated axis
protrusion

a part of a structure that sticks out

pubescent

covered with hairs, generally short soft hairs

ray flowers

generally the show strap shaped flower in the head of a sunflower; as opposed to the less showy disk or tube flower

recurved

curved outward, downward, or backward

reduced

lessened in size or form

rhizomatous

stem growing laterally partly or wholly beneath the soil

root

the portion of the plant, generally below ground, that anchors the plant and absorbs moisture and nutrients from the soil

rosette

dense basal cluster of leaves arranged in a circular fashion about one point usually at ground level

seed

that part of the plant containing the mature embryo from which a new plant can generate

serrate

with sharp teeth directed forward; often said of leaf edges

sessile

without a stalk of any kind; said of a leaf or flower coming right off of a stem

simple

of only one part; not divided into separate segments; not compound

sinus

the depression or recess between two adjoining lobes as in a leaf

stamens

one of the pollen-bearing organs of a flower; male part; made up of filament and anther

stem

the main stalk of a plant; supports leaves, flowers and fruit

terminal

of or at the end of something

toothed

a small marginal lobe; as on a saw, dentate

tuber

a thickened, short, usually subterranean stem having numerous buds called eyes; like a potato

undivided

not divided; of one part

whorled

with three or more leaves or other structures arranged in a circle around a stem or common axis

wings

membranous or thin expansion bordering or surrounding an organ such as a stem

winter annual

an annual plant that germinates in the fall, completing its life cycle the following year