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 Glossary of Plant Terms

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Alternate.  Any arrangement of plant parts (such as leaves) other than opposite or whorled, or can apply to stamens when between the petals.

Annual.  A plant that completes its life cycle (seed germination, 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.

Ascending. Curving or angling upward from base.

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

Banner.  Uppermost, often largest petal of many plants in the pea (Fabaceae) family.

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 below an inflorescence or cone.

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.

Compressed.  Flattened side-to-side or front-to-back.

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.

Dehiscent.  Splitting open at maturity to release contents. Said especially of fruit or anthers.

Dioecious.  Flowers unisexual, the male and female flowers on different plants (contrast monoecious).

Diminutive.  Very small or tiny.

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.

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 without a persistent woody stem above ground.

Inflated.  Blown up; bladdery.

Inflorescence.  The flower cluster of a plant.

Involucre.  A whorl of bracts below a flower cluster inflorescence as in the the heads of plants in the Sunflower Family (Asteraceae).

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.

Monoecious.  Flowers unisexual, the male and female flowers on the same plant (contrast dioecious).

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.

Opposite.  Set against, as leaves when two at a node, or one part before another as a stamen in front of a petal.

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.

Pedicel.  Stalk of an individual flower in a flower cluster of of a spikelet in grasses.

Pedicellate.  Having a pedicel, as opposed to sessile.

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

Perennial.  Living more than two years or growing seasons.

Perfect.  A flower having both stamens and pistils.

Perianth.  The floral envelopes; collectively, the calyx and corolla, especially when they are alike.

Persistent.  Remaining attached, as a calyx on a fruit.

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

Petiole.  Leaf stalk.

Phyllary.  An individual bract on the head (involucre) 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.

Placenta.  Structure or area to which ovules are attached in an ovary, variously shaped and positioned.

Pod.  A dry, dehiscent fruit, especially a fruit of the pea family.

Pubescence.  Covered with short, soft hairs.

Radiate Head.  In the Sunflower Family (Asteraceae), a head composed of central disk flowers and marginal ray flowers.

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.

Sepal.  A leaf or segment of the calyx.

Serrate.  Having margins with sharp teeth.

Sessile.  Without a stalk of any kind; said of a leaf or flower coming right off of a 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.

Spike.  An elogated axis of sessile flowers or spikelets.

Spikelet.  A secondary spike; the ultimate flower-cluster in grasses, consisting of two glumes and one or more florets, and in sedges. 

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.

Strigose.  With stiff, straight, sharp, appressed hairs.

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

Taxon (plural, taxa).  Any taxonomic unit, as an order, genus, species, variety, etc.  The plural term is often used to refer to a combination of species, subspecies, and varieties, e.g., "currently, 539 plant taxa are considered by BLM to be Special Status Species."

Terminal.  At the tip of a structure.

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.

Tufted.  Cluster-like growth habit.

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 spring.