Glossary of Plant Terminology

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achene - n. any small, dry fruit with one seed whose outer covering ( pericarp) does not burst when ripe. Example: sunflower seed.

algae - n. a wide variety of tiny, often microscopic, plants (or plant-like organisms) that live both in water and on land. alga - singular. More information.

alternate (leaf arrangement) - adj. leaves occurring one at a node; one after another, not opposing. See illustration.

anatomy - n. the internal structure of an organism and/or its parts.

angiospermae - n. a major division of the plant kingdom, commonly known as flowering plants; their reproductive organs develop seeds in the flowers. Example: duck potato. angiosperms - plural

anther - n. the top of the stamen, which produces the pollen. See illustration.

aquatic macrophytes - aquatic plants that are large enough to be apparent to the naked eye. They can be grouped into four basic categories. Some are rooted in the bottom sediments but protrude above the water's surface ( emersed ) while others float on the water's surface ( floating and floating-leaved). Still others grow completely below the water's surface ( submersed ).

aquatic plants - plants that grow in water or wet areas; plants that must complete part or all of their life cycle in or near the water. The general term "aquatic plants" usually refers to aquatic macrophytes, but it may be used to refer to both macrophytes and algae. More information.

aquatic vascular plants - aquatic plants containing the conductive vascular tissue, phloem and xylem.

ascending (plant habit) - adj. growing upward, inclined. See illustration.


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bark - n. the outermost covering of trees and some plants. This is composed of the cuticle or epidermis, the outer bark or cortex, and the inner bark or fiber. See illustration.

berry - n. any fleshy simple fruit with one or more seeds and a skin, as a tomato, cranberry, banana, grape, etc.; without a stony layer surrounding the seeds. See illustration and this illustration.

biological control - n. the purposeful introduction of natural enemies (insects, pathogens etc.) as a means of weakening and suppressing invasive plants. More information.

biological productivity - n. the ability of a waterbody (or habitat) to support plants, fish and wildlife. More information.

bipinnately compound (leaf arrangement) - consists of two pinnately compund leaves attached opposite to the same leaf stalk. Also, each pinnately compound leaf consists of two rows of leaflets; arranged one on either side of the leaf stalk. See illustration.

blade - n. the leaf of a plant, especially grass; the flat or expanded portion of a leaf; lamina. See illustration.

bract - n. a modified leaf, growing at the base or on the stalk of a flower; usually differs from other leaves in shape or color. If bright colored, it helps attract pollinators. See illustration .

bud - n. an undeveloped leaf or flower (or both) of a plant. See illustration.

bulb - n. a specialized underground bud that sends down roots and consists of a very short stem covered with leafy scales or layers which store water and nutrients. Not a corm, rhizome or tuber. See illustration.


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calyx (flower part) - n. all sepals of a flower combined together. (calices – plural). See illustration.

cambium - n. in woody plants, the layer of tissue between the bark and wood that produces new cells.

cellulose - n. the chief substance found in the cell walls or woody part of plants; which contributes to their stiffness.

channeled - adj. having a deep longitudinal groove.

clasping (leaf attachment) - adj. leaf partially encircles the stem. Example: West Indian marsh grass.

climbing (plant habit) - adj. growing upward in a winding fashion. See illustration.

competition (among plants) - n. an interaction between two species which can result in a disadvantage to one or both of the species. For example, when an exotic plant is introduced to a habitat outside its normal range, it often competes with native plant species for nutrients, space, sunlight, water, etc. If the exotic plant doesn't have to worry about other "controlling" factors such as hungry insects, bacteria, viruses, it could take over and crowd the native plant species out of the area. For more information, visit exotic plants. For more information, visit native plants.

cordate (leaf base) - adj. with a sinus and rounded lobes at the base; the overall outline is usually ovate or heart-shaped. See illustration.

corm - n. an enlarged rounded solid underground stem, filled with nutrients. See illustration.

corolla - n. the inner, usually colored or otherwise differentiated, whorl or whorls of the perianth; the petals of a flower as a whole. See illustration.

cotyledon - n. the first leaf or leaves of a seed plant, found in the embryo of the seed; may form the first photosynthetic leaves or may remain below ground. Also called seed leaf or leaves.

creek - n. a natural stream of water, which is normally smaller than (and often tributary to) a river.

creeping (plant habit) - adj. growing by spreading out and staying close to the ground. See illustration.

crenate (leaf margin) - adj. having a notched, indented, or scalloped edge. See illustration.

culm - n. the stalk or stem for grasses and sedges and related plants, usually jointed and hollow. See illustration.


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decomposition - n . the breakdown of dead organic material by microorganisms into simpler compounds. More information.

dissolved oxygen - n . a form of oxygen gas (O2) that is constantly entering water from two main sources: the atmosphere and photosynthesis (plants); an indicator of water quality. More information.


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ecology - n. branch of science concerned with the interrelationships of organisms and their environments especially as manifested by natural cycles and rhythms, community development and structure, geographic distributions and population alteration.

ecosystem - n. a community of living organisms (plants, animals, microorganisms, etc.) all of which interact among themselves and the environment where they live (on land, in the soil or in the water, etc.). They are often defined by the plants and animals living within the community (a marsh, a wetland or a coral reef, for example). Ecosystems do not always have distinct boundaries; they can be as small as a mud puddle or as large as a continent or even the earth itself.

elliptic (leaf shape) - adj. having the form of an oval or ellipsis; widest in the middle, similar to the outline of a football. See illustration.

emergent plants - same as emersed.

emersed - adj. rooted in shallow water and having most of the vegetative growth above the water. More information.

entire (leaf margin) - adj. having a margin devoid of any indentations, teeth, or lobes. See illustration.

erect (plant habit) - adj. vertical; upright standing. See illustration.

Eutrophic (waterbody) – adj. contains high concentrations of nutrients; the waterbody will either have lots of aquatic plants and clear water or it will have few aquatic plants and lots of algae (less clear water). Has the potential to support lots of fish and wildlife. More information.

eutrophication - adj. contains high concentrations of nutrients; the eaterbody will either have lots of aquatic plants and clear water or it will have few aquatic plants and lots of algae (less clear water). Has the potential to support lots of fish and wildlife. More information.

exotic - adj. and/or n. purposefully or accidentally introduced species to a native habitat (Example: from a natural range outside of Florida). Not necessarily invasive. More information.


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filament - n. a stalk; the part of a flower that holds the anther. See illustration.

floating-leaved plant - n. a plant that may or may not be anchored to the sediment, but has leaves that float on the surface of the water.More information.

food web - n. feeding relationships between plants and animals in an area or ecosystem.


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habitat - n. the locality or external environment in which a plant lives. See illustration.

herb - n. any seed plant whose stem withers away to the ground after each season's growth; a seed plant with a green, non-woody stem. Example: lyre-leaf sage.

herbaceous plants - adj. soft, grassy, non- woody plants that according to season (autumn) lose their above-ground growth but leave intact roots and produce new growth in the new season (spring).

herbicide - n. a chemical used to control the growth of invasive plants. More information.

herbivore - n. an animal that eats only plant material. This group includes many insects (aphids, wasps, etc.) and mammals (rabbits, mice, deer, squirrels, elephants, etc.).

hypereutrophic waterbody - adj. contains very high concentration of nutrients; supports large amounts of algae and/or plants, fish and wildlife; water is murky. More information.

hybrid - n. any cross-bred plant.


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immersed - adj. completely covered with liquid; submerged. To be completely involved or occupied.

indigenous - adj. native; originating or occurring naturally in a specific area. Example: cattails are indigenous to Florida. More information.

inflorescence - n. a cluster or arrangement of flowers on an axis; a flowering branch. Example: sawgrass. Photograph examples one and two.

internode - n. the portion of a stem between nodes. See illustration.

interspecific competition - competition among different species for nutrients, space, light, etc.

intraspecific competition - when an individual plant competes with one or more members of the same species for nutrients, space, light, etc.

invasive exotic plant - an exotic plant species that is expanding on its own in native plant communities, endangering the existence of native species. Example: water hyacinth.

invasive plant - a non-native plant species that is able to spread on its own, causing environmental or economic harm. More information.


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lacerate ­(leaf margin) - adj. with an irregularly torn margin. See illustration.

lake - n. an inland body of water, usually fresh water, formed naturally by glaciers, river drainage, sink holes, earthquake activity etc.; larger than a pool or pond. More information.

lanceolate (leaf shape) - adj. shaped like a lance; broadest toward the base and narrowedat the tip; several times longer than wide. See illustration.

leaf - n. part of a plant; an outgrowth from the stem, usually flat in structure and green in color. The part of the plant where most of the transpiration and photosynthesis processes occur. See illustration.

ligule - n. thin, membranous extension of the leaf sheath on the upper surface of the leaf; may be hairy or bristly, hard or soft. Example: vasey grass.

limnology - n. the scientific study of physical, chemical, meteorological, and biological conditions of inland waterbodies. More information.

linear (leaf shape) - adj. long and slender with parallel or nearly parallel sides. See illustration.


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margin - n. boundary line; the edge (ex. of a leaf). See illustration.

macrophyte - n. see aquatic macrophyte.

maintenance control - controlling exotic weeds on a continuous basis, using a variety of techniques (biological, chemical, mechanical), so troublesome plants can be kept at the lowest feasible levels. More information.

marsh - n. a tract of wet land principally inhabited by emergent herbaceous vegetation. Usually a transition between land and water. More information.

mechanical control - the use of machines to shear, crush, shred, press, pull and remove aquatic weeds from waterbodies. More information.

mesotrophic (waterbody) - adj. contains moderate concentrations of nutrients and supports a moderate amount of algae and/or plants, fish and wildlife. More information.

midrib - n. central and most prominent vein of a leaf or leaflet. See illustration.


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native plant – a plant species that occurs naturally in a geographic region or area (also referred to as an indigenous plant); it has not been introduced by humans (intentionally or unintentionally). More information

naturalize - v. to adapt to a non-native environment; when a species of foreign origin, established itself and reproduces (outside cultivation) as though it is native.

naturalized exotic - an exotic plant that sustains itself outside of cultivation. (Note: this does not mean that it has "become" native).

node - n. a knob or joint of a stem from which leaves, roots, shoots, or flowers may arise. A node may contain one or more buds. See illustration.

non-native plant – a plant species that is present in a region outside its original, historic range due to intentional or unintentional introduction; not necessarily invasive. Also referred to as non-indigenous or exotic. The introduction of the plant to a new area is often the result of human activity. More information.

nutrients - chemicals that algae and aquatic plants (macrophytes) need for growth. Nitrogen and phosphorous are two of the most common nutrients found in Florida soils. More information.


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oblanceolate (leaf shape) - adj. shaped like a lance point reversed; having the tapering point next to the leafstalk. See illustration.

oblong (leaf shape) - adj. elliptical, slightly rectangular and from two to four times longer than it is broad. See illustration.

obovate (leaf shape) - adj. inversely ovate; roughly the shape of an egg, with the broad end at the top. See illustration.

oligotriphic (waterbody) - adj. water that contains very low concentrations of nutrients. Biologically less productive; supporting small amounts of algae, few plants and fish. Water is clear. More information.

Opposite (leaf arrangement) - adj. leaves or bracts on opposite sides of the stem/twig; occurring two at a node, directly across from one another. See illustration.

orbicular (leaf shape) - adj. almost circular or shield-shaped. See illustration

ovate (leaf shape) - adj. egg-shaped and with the broader end towards the base. See illustration.

ovule - n. part of a seed plant that develops into a seed after fertilization; it contains the megasporangium (nucellus), megaspore (embryo sac), a food store, and a coat.


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palmately compound (leaf arrangement) - leaflets that originate from a common center. See illustration.

pathogen - n. an organism that causes disease in another organism; usually a virus, bacterium or fungus. More information.

peltate (leaf base and attachment) - adj. round shield-shaped leaves, attached to the stem at the center. See illustration.

perianth - n. the outer whorl of floral leaves of a flower; collectively, the calyx and corolla, or either one; if one is absent. See illustration.

petal - n. the colored parts of the corolla (most of the time), usually arranged in a circle; most visible part of the flower. See illustration.

petiole - adj. the slender stalk or stem of a leaf (small foot); also called a leaf stalk. See illustration.

petiolate (leaf attachment) - petiole (leaf stalk) is present. See illustration.

phloem - n. the tissue forming part of a plant's vascular system; used by the plant to transport carbohydrates and other organic (food) materials from the leaves to the rest of the plant.

photosynthesis - n. a chemical process that takes place in virtually all plants including aquatic plants and algae (and many forms of bacteria). Using three simple ingredients (carbon dioxide, water, and sunlight), plants and bacteria are able to make their own food. More information.

pistil – n. the female reproductive organ of a flower; may be comprised of a single carpel (consisting of stigma, style and ovary) or two or more carpels united. See illustration.

plant - n. a major group of living beings that typically lack locomotive movement or obvious sensory organs, and are generally capable of making their own food. This group includes at least 300,000 species including aquatic macrophytes, some planktonic algae, ferns, flowers, grasses, herbs, trees, etc.

pollen - n. a fine powder-like material (grain) that is produced within the anther (in seed plants); these grains carry the male DNA of the plant.

pond - n. a body of standing water smaller than a lake, often artificially formed. More information.

primary production - refers to growth produced by organisms at the bottom of the food chain (plants, algae, etc.) which, in turn, fuels the rest of the food chain.

productivity - n. amount of production over a given period of time. Expressed as a rate such as g/m2 per day, kg/ha per year, etc. See biological productivity.

propagulum or propagule - n. a runner or sucker used in the asexual reproduction and dispersal of plants. (propagula or propagules – plural).


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rachis - n. the main axis of an inflorescence. See leaf illustration and inflorescence illustration.

reniform (leaf shape) – adj. having the shape of a kidney. See illustration.

rhizome - n. a subterranean horizontal root-like stem sending out leaves and shoots from its upper surface and roots from its lower surface. See illustration.

root - n. the part of a plant, usually below ground, that holds the plant in position, draws water and nutrients from the soil, stores food, and is typically non-green, without buds or leaves. See illustration.

rosette (leaf arrangement) - adj. clustered and crowned around a common point of attachment. See illustration.

rounded (leaf base) - adj. arched or circular in shape rather than pointy and/or angled. See illustration.

runner - n. a slender creeping stem that puts forth roots from nodes, spaced at intervals along its length. New plants eventually grow from the nodes and can become detached from the parent plant. Example: St. Augustine grass.


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sagittate (leaf base) - adj. shaped like an arrow with the basal lobes pointing downward. See illustration.

sedimentation - n. the act or process of deposition of decomposed organic material on the bottom of a waterbody, often called muck. More information.

Secchi disk - a small black and white disk used to measure water clarity. More information.

seed - n. the part of a flowering plant that contains the embryo and will develop into a new plant if sown; a fertilized and mature ovule.

sepal - n. any of the leaf divisions of the calyx; part of the outer floral leaves, usually green. See illustration.

serrate (leaf margin) - adj. having sharp notches along the edge pointing toward the apex. Called double serrate if small serratures intermingle with big, as in the elm. See illustration, images of serrate leaf and double serrate leaf.

sessile (leaf attachment) - adj. sitting directly on a main stem or branch without the support of a leaf stalk. See illustration.

sheath - n. the protective covering; the lower part of a leaf that envelopes stem or culm. See illustration.

shoot - n. a young branch/leaf that shoots out from the main stock.

spatulate (leaf shape) - adj. shaped like a spatula or spoon, gradually widening distally and with a rounded tip. See illustration.

species - n. a group of successfully interbreeding individuals.

spikelet - n. a subdivision of a spike; the parts that contain the flowers of the plant; often have scales and/or bristles. See illustration.

spore - n. any of various small reproductive bodies, often consisting of a single cell, produced asexually or by the union of gametes (as in mosses, ferns, etc.).

sprawling (leaf habit) - adj. spread out in different directions. See illustration.

squared (leaf base) - adj. having the shape of a square; having right angles. See illustration.

stamen - n. the male reproductive organ of a flower; situated within the petals and in most cases is composed of the filament and the anther, that produces pollen. See illustration.

stem - n. the main axis of a plant, typically above the soil surface; generally supports the leaves. See illustration.

stem tuber - n. a swollen structure produced by stolons and runners which remains dormant during adverse conditions and later grows into a new plant when the conditions become favorable for growth.

stigma - n. the upper tip or part of the pistil of a flower receiving the pollen. It is generally situated at the upper extremity of the style. See illustration.

stipule - n. a small leaf-like or membranaceous growth at base of a leaf petiole. See illustration.

stolon - n. a slender modified stem growing along the ground, rooting at the nodes and developing a new plant; horizontally growing stem. Example: strawberry. See illustration.

stoma - n. one of the minute openings in the epidermis of leaves, stems, and other plant organs through which gases are exchanged between the atmosphere and the intercellular spaces. stomata – plural.

style - n. slender upper part of the pistil, supporting the stigma of a flower. See illustration.

submerge - v. to sink or plunge beneath the surface of water.

submersed plants - plants growing with their root, stems, and leaves completely under the surface of the water. Sometimes the leaves and/or flowers may grow above the surface. Example: vallisneria. More information.

swamp - n. low ground filled with water; a wooded area having surface water much of the time. More information.


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tannins - n. tea colored organic dissolved compounds that originate from many types of terrestrial and aquatic plants; can affect the color of a waterbody.

taxonomy - n. the scientific classification of organisms, based on natural relationships. More information.

trophic state - n. category used to classify a lake or waterbody based on its biological productivity; usually determined using four water chemistry parameters: chlorophyll, total nitrogen, total phosphorus and water clarity. More information.

tuber - n. the short, thickened fleshy food-storing portion of an underground stem with many surface buds, generally shaped like a rounded protuberance. See illustration.

turion - n. a young scaly shoot budded off from underground stems; detachable winter bud used for perennation (the process of living through a number of years) in many aquatic plants. See illustration.

tussock - n. a drifting mass of peat, mud and plants; often referred to as a “floating island.” More information.


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undulate (leaf margin) - adj. having a wavy edge. See illustration.


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vascular - adj. containing a system for carrying or circulating fluids, such as sap and/or water, through the body of a plant.

vascular bundle - n. part of the transport system found in vascular plants; used to transport water and/or nutrients within the plant; strand-like, contains the xylem and phloem.

vegetative propagation - reproduction of plants using a nonsexual process involving stems, leaves and parts of the mother plant; the process does not involve production of seeds or spores.


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water clarity - a measure of how far you can see into the water; its visible depth. More information.

weed - n. any plant that crowds out a cultivated and desired plant.

wet weight - n. the weight of plants after the outer surface covering of water has been removed. Wet weight is not a reliable measurement since methods to prepare plants prior to weighing vary considerably; same as the fresh weight.

wet woodland - a wooded area having surface water some of the time, for intermittent short periods.

whorl (leaf arrangement) - n. parts of a flower, or leaves (three or more at a time) arising from one node; vertical. A circle of flowers. See illustration.

woody plants - plants that have woody stems and grow continuously throughout the year, many years in a row, without losing their above-ground growth with the change of seasons. Example: Hypericum fasciculatum.


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xylem - n. woody tissue that is part of the water-transport system in plants and also acts as supporting tissue.


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