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Glossary of Plant Terms

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Adventitous. Appearing in an abnormal or unusual position or place; occurring as a straggler or away from its natural position, such as roots on aerial stems.

Alternate.
Arranged singly, often spirally, along an axis; sometimes occurring between structures or in different ranks (e.g. leaves on a branch, or branching itself) or can apply to stamens when between the petals.

Annual.
Completing life cycle (seed germinations, flowering, and death) in one year or growing season.

Appressed.
Pressed against. Especially hairs that are parallel or nearly parallel to and often in contact with the surface or axis of origin.

Awn.
A slender bristle-like appendage usually at the end of a structure.

Banner.
Uppermost, often largest petal of many plants in the Pea Family (Fabaceae).

Basal.
Of or at the base.

Biennial.
Completing the life cycle in two growing seasons.

Bract.
A small leaf or scale-like structure associated with and subtending an inflorescence or cone.

Bractlets: Relatively small, generally secondary bract within an inflorescence.

Calyx.
Outer whorl of flowering parts; collective term for all the sepals of a flower.

Capsule.
A dry fruit of more than one carpel which opens to release the seeds.

Cespitose.
Growing in tufts.

Clasping.
Leaf partly or wholly surrounding the stem.

Compound: Composed of two or more parts; Leaf divided into distinct parts; Repeating a structural pattern (a compound umbel is an umbel of umbels).

Corolla
. Inner whorl of floral parts; collective name for petals.

Creeping.
To grow along the ground or some structure.

Culm.
The jointed stem of a grass that supports the leaves and elevates the flowering structure.

Cyme.
Branched inflorescence in which the central or uppermost flower opens before the peripheral or lowermost flower on any axis.

Dioecious.
Flowers unisexual, the male and female flowers on different plants.

Diminutive.
Very small or tiny.

Elongate.
Lengthened.

Entire.
Margins smooth without teeth or lobes.

Fleshy.
Thick and juicy; succulent.

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.

Glaucous.
Having a waxy or powdery, bluish-white or bluish-gray bloom that can be rubbed off.

Glandular
. Bearing glands.

Glume.
In grasses, each of generally two sheathing bracts that are the lowermost parts of a spikelet.

Habit.
Characteristic growth form or shape of a plant.

Habitat.
Natural setting where a plant grows. Usually refers to a specific plant community.

Herb
. Plant with little or no wood above ground; above-ground parts are of less than one year or growing season duration.

Inflated.
Blown up; bladdery.

Inflorescence.
The flower cluster of a plant; Entire aggregation of flowers or flower clusters and associated structures (e.g. axes, bracts, bractlets, pedicels); often difficult to determine as to type and boundaries but generally excluding full-sized foliage leaves.

Keel.
Ridge or crease more or less centrally located on the long axis of a structure.

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

Lateral.
Referring to side(s) of a structure.

Leaflet.
Segment of compound leaf.

Leafy.
Having numerous leaves.

Lemma.
In grasses, the lower, generally larger of two sheathing bracts that occur directly below a flower.

Ligule.
In grasses, an appendage at the juncture of leaf sheath and blade, generally with a membranous or fringed margin.

Linear.
Resembling a line; long and narrow of uniform width.

Lobe.
A major expansion or bulge-like shape, as at the margin of a leaf or petal.

Margin.
The edge, generally of a leaf.

Monoculture.
Only one species present.

Node.
Position on a stem from which one or more structures (especially leaves) arises.

Oblanceolate.
Leaf blades that are wider above the middle and toward the tip than at the stem.

Oblong.
Two to four times longer than wide with the sides nearly parallel as in a leaf.

Ovate.
With the outline of an egg in longitudinal section, widest below the middle.

Ovule.
Structure containing an egg; a seed prior to fertilization.

Panicle.
Branched inflorescence in which the basal or lateral flowers (or some of them) open before the terminal or central flowers on any axis; loosely branched, pyramidal flower clusters.

Pedicel.
Stalk of an individual flower or fruit.

Pedicellate.
Having a pedicel.

Peduncle.
The stalk of a flower or of a flower cluster.

Perennial.
Living more than two years or growing seasons.

Perianth.
Collectively, the calyx and corolla, especially when they are alike.

Persistent.
Remaining attached after like parts normally fall off.

Petal.
One of the leaves of a corolla, often conspicuously colored.

Petiole.
Leaf stalk.

Phyllaries.
Phyllary; the name of the bract on the head of a sunflower.

Pinnate.
Compound leaf with the leaflets on two opposite sides of an elongated axis.

Pistil.
The ovule-bearing organ of a flower, consisting of stigma and ovary, usually with a style in between.

Pod.
A dry, dehiscent fruit.

Pubescence.
Covered with short, soft hairs.

Ray Flowers.
Generally the showy strap shaped flower in the head of a sunflower; as opposed to the less showy disk or tube flower.

Recurved.
Gradually curved downward or backward.

Scabrous.
Rough to the touch, generally due to short stiff hairs.

Scarious.
Thin, dry, pliable, dark-colored or translucent but not green. Often like a dry onion peel.

Senesce: A period in the life cycle of a plant that occurs from maturity to death.

Sepal.
A type of leaf or segment of the calyx.

Serrate.
Having margins with sharp teeth.

Sessile.
Without a petiole, peduncle, pedicel, or stalk of any kind; said of a leaf or flower coming right off of a stem.

Sheath: Surrounding or partially surrounding, often tubular structure or part of a structure, such as a leaf base.

Sheathing: Sheet-like structure at the leaf base that encircles the stem.

Silique.
A many-seeded capsule of the Mustard Family (Brassicaceae) with two valves splitting from the bottom and leaving the placentae with the false partition between them.

Spiciform.
 Shaped like a spike.

Spikelet.
In grasses, the smallest aggregation of florets, plus any that occur below the glumes.

Stamen.
The male organ of the flower which bears pollen.

Stigma.
The receptive part of the pistil on which the pollen germinates.

Stipule.
Appendage at base of leaf stalk, often leaf- or scale-like.

Stout.
Thick, sturdy, not slender.

Style.
The contracted portion of the pistil between the ovary and the stigma.

Succulent.
A plant with thick fleshy leaves and/or stems that are adapted to store water.

Taxon (plural of taxa).
A group of plants, under the scientific classification system (e.g. a genus or species).

Terminal.
At the tip of a structure.

Tillering.
Vegetative reproduction accomplished by producing basal or subterranean shoots that are more or less erect.

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.

Tussock.
A tuft, or small hillock of growing grass.

Tufted.
Cluster-like growth habit.

Umbel. A branched inflorescence characteristic of the Parsley/Carrot Family (Apiaceae) that consists of arranged flowers attached individually by elongated pedicels to a central axis; the flowers form a flat-topped or convex shape like an umbrella.

Whorl.
Group of three or more structures of the same kind (generally leaves or flower parts) at the same node.

Winter Annual. An annual plant that germinates in the fall, completing its life cycle the following year.



Source:

Baldwin, B.G., D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken. The Jepson Manual, Vascular Plants of California, Second Edition, Thoroughly Revised and Expanded. 2012.


 
Last updated: 08-23-2012