PCA Weeds Study Guide Exam 2025-2026
1. Summer Annual Emerge in the spring or early summer, grow during the summer, produce seed
Weeds in mid to late summer, and are killed by frost in fall/early winter.
2. Winter Annual Typically emerge late summer or fall, survive through the winter by growing into
Weeds small rosettes, then resume their growth and produce seeds in late spring or
early summer the following year.
3. Perennials Plants that live 3 or more years, repeating the vegetative growth and reproductive
cycles each year.
4. Biennials Angiosperms that complete their life cycle in two years, usually don't flower or
reproduce until the second season.
5. Dicot angiosperm with two cotyledons inside its seed, flower parts in multiples of four
or five, and vascular bundles in rings
6. Monocot angiosperm with one seed leaf in its ovary
7. cotyledon first leaf or first pair of leaves produced by the embryo of a seed plant
8. first true leaves primary leaves
, PCA Weeds Study Guide Exam 2025-2026
9. collar region Region consisting, leaf blade, leaf sheath, auricles (if present), a ligule, and
connective collar
10. Leaf blade flattened part of leaf
11. Node point where one or more leaves are attached
12. Internode A segment of a plant stem between the points where leaves are attached.
13. leaf sheath the base of a leaf that wraps around the stem; typical in grasses and some other
monocots.
, PCA Weeds Study Guide Exam 2025-2026
14. Petiole The stalk of a leaf, which joins the leaf to a node of the stem.
15. Auricle Claw like appendages on collar
16. Ligule A membranous or hairy structure on the inside of a leaf at the junction of the leaf
blade and sheath
17. Awn bristlelike appendage of certain grasses
18. Hypocotyl The part of a plant embryo directly below the cotyledons, forming a connection
with the radicle.
1. Summer Annual Emerge in the spring or early summer, grow during the summer, produce seed
Weeds in mid to late summer, and are killed by frost in fall/early winter.
2. Winter Annual Typically emerge late summer or fall, survive through the winter by growing into
Weeds small rosettes, then resume their growth and produce seeds in late spring or
early summer the following year.
3. Perennials Plants that live 3 or more years, repeating the vegetative growth and reproductive
cycles each year.
4. Biennials Angiosperms that complete their life cycle in two years, usually don't flower or
reproduce until the second season.
5. Dicot angiosperm with two cotyledons inside its seed, flower parts in multiples of four
or five, and vascular bundles in rings
6. Monocot angiosperm with one seed leaf in its ovary
7. cotyledon first leaf or first pair of leaves produced by the embryo of a seed plant
8. first true leaves primary leaves
, PCA Weeds Study Guide Exam 2025-2026
9. collar region Region consisting, leaf blade, leaf sheath, auricles (if present), a ligule, and
connective collar
10. Leaf blade flattened part of leaf
11. Node point where one or more leaves are attached
12. Internode A segment of a plant stem between the points where leaves are attached.
13. leaf sheath the base of a leaf that wraps around the stem; typical in grasses and some other
monocots.
, PCA Weeds Study Guide Exam 2025-2026
14. Petiole The stalk of a leaf, which joins the leaf to a node of the stem.
15. Auricle Claw like appendages on collar
16. Ligule A membranous or hairy structure on the inside of a leaf at the junction of the leaf
blade and sheath
17. Awn bristlelike appendage of certain grasses
18. Hypocotyl The part of a plant embryo directly below the cotyledons, forming a connection
with the radicle.
