Page 1 of 38
PCA EXAM WEEDS STUDY GUIDE | {LATEST
2026/ 2027 UPDATE} COMPLETE ACTUAL AND
AUTHENTIC EXAM | BRAND NEW!
Summer Annual Weeds
Emerge in the spring or early summer, grow during the summer,
produce seed in mid to late summer, and are killed by frost in
fall/early winter.
Winter Annual Weeds
Typically emerge late summer or fall, survive through the winter
by growing into small rosettes, then resume their growth and
produce seeds in late spring or early summer the following year.
Perennials
Plants that live 3 or more years, repeating the vegetative growth
and reproductive cycles each year.
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Biennials
Angiosperms that complete their life cycle in two years, usually
don't flower or reproduce until the second season.
Dicot
angiosperm with two cotyledons inside its seed, flower parts in
multiples of four or five, and vascular bundles in rings
Monocot
angiosperm with one seed leaf in its ovary
cotyledon
first leaf or first pair of leaves produced by the embryo of a seed
plant
first true leaves
primary leaves
,Page 3 of 38
collar region
Region consisting, leaf blade, leaf sheath, auricles (if present), a
ligule, and connective collar
Leaf blade
flattened part of leaf
Node
point where one or more leaves are attached
Internode
A segment of a plant stem between the points where leaves are
attached.
leaf sheath
the base of a leaf that wraps around the stem; typical in grasses
and some other monocots.
, Page 4 of 38
Petiole
The stalk of a leaf, which joins the leaf to a node of the stem.
Auricle
Claw like appendages on collar
Ligule
A membranous or hairy structure on the inside of a leaf at the
junction of the leaf blade and sheath
Awn
bristlelike appendage of certain grasses
Hypocotyl
The part of a plant embryo directly below the cotyledons, forming
a connection with the radicle.
PCA EXAM WEEDS STUDY GUIDE | {LATEST
2026/ 2027 UPDATE} COMPLETE ACTUAL AND
AUTHENTIC EXAM | BRAND NEW!
Summer Annual Weeds
Emerge in the spring or early summer, grow during the summer,
produce seed in mid to late summer, and are killed by frost in
fall/early winter.
Winter Annual Weeds
Typically emerge late summer or fall, survive through the winter
by growing into small rosettes, then resume their growth and
produce seeds in late spring or early summer the following year.
Perennials
Plants that live 3 or more years, repeating the vegetative growth
and reproductive cycles each year.
,Page 2 of 38
Biennials
Angiosperms that complete their life cycle in two years, usually
don't flower or reproduce until the second season.
Dicot
angiosperm with two cotyledons inside its seed, flower parts in
multiples of four or five, and vascular bundles in rings
Monocot
angiosperm with one seed leaf in its ovary
cotyledon
first leaf or first pair of leaves produced by the embryo of a seed
plant
first true leaves
primary leaves
,Page 3 of 38
collar region
Region consisting, leaf blade, leaf sheath, auricles (if present), a
ligule, and connective collar
Leaf blade
flattened part of leaf
Node
point where one or more leaves are attached
Internode
A segment of a plant stem between the points where leaves are
attached.
leaf sheath
the base of a leaf that wraps around the stem; typical in grasses
and some other monocots.
, Page 4 of 38
Petiole
The stalk of a leaf, which joins the leaf to a node of the stem.
Auricle
Claw like appendages on collar
Ligule
A membranous or hairy structure on the inside of a leaf at the
junction of the leaf blade and sheath
Awn
bristlelike appendage of certain grasses
Hypocotyl
The part of a plant embryo directly below the cotyledons, forming
a connection with the radicle.
