Leaf and Vegetative Terminology Flashcards
Describe Alternate Leaves:
Leaves that grow singly, or take turns growing on each side of the stem. (*think footprints, spiral staircases, & in between)
Describe Opposite Leaves:
Leaves that grow directly across the stem from each other.
Describe Whorled Leaves:
Three or more leaves growing out of the same spot on the stem (like umbrella spines.)
Can a plant have more than one leaf configuration? Name an example.
Uncommon, but yes. Wild yams’ leaves are whorled at the base, turn to opposite mid-vine, and finally alternate at the top of the stem.
What is another word for compound leaf?
Divided
Describe a Single Leaf:
Leaves that grow as a single entity, like lettuce
Describe a Compound Leaf:
Leaves that divide into further segments (leaflets) at the midrib or petiole, like parsley or carrot.
Describe Pinnately Compound Leaves:
Leaflets are arranged on either side of the centrally elongated axis. (eg. ash - Fraxinus spp., hickory - Carya spp., and sumac - Rhus spp.)
Describe Bi-Pinnately Compound Leaves:
Doubly pinnate, or twice-compound, leaflets are further divided into even smaller segments. (eg, mimosa - Albizia julibrissin, and honey locust - Gleditsia triacanthos)
Describe Tri-Pinnately Compound Leaves:
Triply pinnate, or thrice-compound, leaflets are further divided into smaller segments, which are in turn divided into even smaller segments. (eg, heavenly bamboo - Nandina domestica)
Describe Palmately Compound Leaves:
Leaflets radiate from a central point, much like fingers on the palm of a hand. (eg, buckeye - Aesculus spp., and horse chestnut - A. spp.)
What is the Bob Marley trick for telling the difference between leaves and leaflets?
“One bud, one leaf, lets get together and botanize…” True leaves have buds growing at their base on the stem, leaflets do not.
Define Petiole
The leaf stalk - the conjoining point between midrib and the stem.
What is a petiole-less leaf called?
A sessile (stalkless)
Define Midrib
The central vein running up the center of the leaf.
Define Blade
The broad, photosynthetic surface of the leaf.
Define Margin
The edge, or border, of the leaf.
What is a Node?
The part of the stem from which one or more leaves emerge.
What is a Stipule?
Leafy appendage at the node; green outgrowths at the base of the petiole.
What is a Lateral Bud?
A bud that rests in the node, between the petiole and the stem, as opposed to the tip of the branch.
What are Basal Leaves?
Leaves that emerge from a central point in the earth rather than from a stem. (Leaves are clustered at the base of the stem and are often called the “basal rosette”)
Define Lobed
A leaf with deeply indented margins (not toothed, though leaves can be both)
Define Pubescent
Hairy.
Define Glabrous
Hairless (smooth.)
