Glossary

when a plant sheds one of its parts, such as leaves, flowers, and/or fruits

A fruit that has developed from a single flower having many separate pistils, but in addition, part of the flower structure develops into part of the fruit. Such is the case with a strawberry, in which several pistils developed into tiny achenes (see achene) imbedded on the surface of the flower's expanded and succulent receptacle (what we think of as "seeds" of the strawberry are, in reality, individual fruits).

A dry, indeshiscent, one-seeded fruit that has developed from one flower having a single ovary, and the ovary wall becomes rigid at maturity (such as a sunflower "seed" - which is a fruit).

Active transport uses cellular energy to accomplish the transport of molecules, unlike passive transport (such as osmosis) which does not use cellular energy.

Structures or organs developing in a place/position where it is not normally expected, such as a root or bud that arises along a stem internode

A root that exists and functions only above the soil/substrate or water surface (wholly above ground)

A fruit that has developed from a single flower having many separate pistils. Such is the case when the pistils develop into a tight cluster of fleshy drupelets (see drupe) on the surface of the flower's receptacle (such as a raspberry or blackberry).

Leaves and branches that are not opposite to each other on the stem or axis, but occur singly at each node

A seed plant species that produces flowers - in which the ovules are contained within an ovary; the ovary maturing to a fruit containing the seeds (fertilized and matured ovules)

A plant which germinates from seed, flowers, sets seed, and dies in the same year.

A plant species that completes its life cycle (germination of a seed, flowering, reproduction, and senescence) within a duration of one year

part of the male flower parts that holds the pollen intended to be carried (via wind or insects) to a female flower's stigma and subsequently fertilize ovules

The top or tip of a structure, organ, such as a leaf or stem (and the point farthest from the point of attachment)

Reproduction (seed production) without fertilization

Plant species that grow in water: whose seeds germinate in water or in the bottom soil of bodies of water, usually having submersed or floating leaves

An appendage growing attached to a seed, either growing at or near the hilum of a seed, or a fleshy thickening of the seed coat

Propagation of plants by means other than fertilization (sexual); natural methods (apomixis, bulbils/cormels/offsets and other clones, layering) or human-induced (cuttings, layering, division of clumps, and tissue cultures)

The horizontal direction to which a mountain slope faces.

Refers to organisms that are capable of producing their own nutritive substances - processing inorganic materials into organic ones (feed themselves) by using energy from outside the organism such as with photosynthesis (sunshine on chlorophyll)

The point of the angle formed between a leaf or branch where it is joined to a stem (axis)

As pertains to stems: situated in or arising in an axil (such as those occurring at a stem node). A side shoot or bud; typically situated in the axil at a stem node - lateral buds are typically axillary

A fleshy or pulpy, several-seeded fruit that has developed from one flower having a single ovary divided into several carpels, and is fleshy or pulply throughout without a tough rind (such as a tomato).

A plant species that completes its life cycle (germination of a seed, flowering, reproduction, and senescence) within a duration of two years or seasons, with the second season typically devoted to reproduction (flowering and fruiting)

The total mass of all living organisms in a given area, but in this instance pertaining to the total plant mass produced, vegetative and reproductive

A very large regional community, or major ecosystem, of the earth which is distinguished by its climate, fauna and flora - such as grass savanna, desert, temperate forest, or the Arctic tundra.

Twice pinnate; a leaf blade divided into leaflets and having twice-diverged branching

Bracts can appear leaf-like or petal-like: such as a reduced leaf, or modified leaf, that subtends a flower or inflorescence, or sometimes occurs along a stem. Or, on occasion, bracts are highly colored and surrounding tiny flowers, such as with poinsetta, bougainvillea, and dogwood. In conifers - within a cone, the structures arising from the cone axis that support the ovules are often called bracts (strictly, they are sporophylls).

A small bract or secondary bract, such as one occurring upon the pedicel of a flower

Refers to a plant or plant species which does not have needles or grass-like leaves

The collective offspring of an animal, usually hatched and cared for at one time.

Leaves, twigs, and young shoots of trees or shrubs, which animals feed on.

A small, modified leaf or bract that covers and surrrounds, and protects, buds

The scar left by a bud's protective leaf scale

(buff) A brownish yellow to yellowish brown color such as that of dried grasses. This color may be infused with hints of gray or pink and is most often used in describing bird plumage.

A short underground stem having fleshy scales or leaves (storage leaves) that surround a bud/meristematic region, such as an onion

A small bulb that arises from the base of a larger bulb, generated by asexual reproduction

A small bulb or bulb-shaped body, borne above ground typically upon the stem in a leaf axil, generated by asexual reproduction

Tiny, somewhat circular dots within a leaf scar, caused by the separation/breaking of the fibrovascular bundles which pass through a leaf petiole into the leaf blade. Left once a leaf drops off from the stem of a plant

The plant calibration species are a set of 20 plants selected to help "calibrate" phenological measurements across the USA. These native and introduced plants have broad distributions and are ecologically or economically significant. Observations on calibration species will be integrated to get "the big picture" regarding plant response to environmental change. Observers are encouraged to include at least one calibration species in their monitoring projects. Widespread observation of calibration species helps integrate collective plant data with climate change measurements nationwide.

The outer whorl of the flower's perianth and the collective terminology for all of the sepals of a flower; typically green and which often protect the flower bud

A cylinder of meristematic plant tissue (lateral meristems) of many woody seed-bearing plants, producing new xylem towards the inside of a plant (stem, root) and new phloem to the outside of a plant (stem, root). The vascular cambium forms tissues, xylem and phloem, that carry water and nutrients throughout the plant. Addition of the new tissue causes the diameter to increase. The cork cambium creates cells that eventually become bark on the outside and cells that add to the cortex on the inside.

A layer of vegetation elevated above the ground. It can refer to the layer of leaves surrounding an individual tree or shrub, or to the continuous layer of vegetation that comprises the top layer of a forest.

The tree species that comprise a forest canopy

A tightly clustered inflorescence of unstalked flowers, sometimes flat (like daisies or dandelions) or globular (like buttonbush)

A dry, dehiscent fruit that has developed from one flower having a single ovary divided into several carpels - often fused, and splitting open along a seam of the carpel or opening at pores at maturity.

The simplest unit within a pistil (ovary, style, stigma). A simple pistil has one carpel (ovary, style, stigma) or a compound pistil has multiple carpels (each having an ovary, stigma, style - joined in various ways)

A grain, such as for grasses; a dry, indeshiscent fruit that has developed from one flower having a single ovary, where the seed coat is fused to the ovary wall.

A small, modified leaf or bract that can surround vegetative or floral meristems (buds and growing points), or occur on a rhizome; commonly providing protection

An inflorescence (cluster of flowers) consisting of a dense spike or raceme of apetalous, unisexual flower as in Salicaceae and Betulaceae; an ament (a cylindrical flower cluster).

A membrane-bound body found within a cell's cytoplasm that performs specific cellular functions

The minimum period of cold weather needed, after which a fruit-bearing tree will blossom. It is often expressed in hours

The organelle within the cell which contains chlorophyll, and is necessary for photosynthesis to occur (see photosynthesis)

An organized structure of DNA, protein, and RNA found in cells. It is a single piece of coiled DNA containing many genes

A flattened, leaf-like stem or branch which functions like a leaf

A group of individuals originating from a single parent plant through vegetative reproduction.

A group of individual plants all originating by vegetative propagation (asexual) from a single plant, and therefore genetically identical to it and to one another

To reproduce or propagate asexually. 

Genetically identical plants. The cloned plant component of the USA-NPN Plant Phenology Program offers monitoring of a small group of species, including the cloned lilac,that will eventually be distributed nationwide.

A plant that has originated by vegetative propagation (asexual) from another plant, and therefore is genetically identical to it

In monocotyledons/monocots, the first leaf following the cotyledon, which forms a protective sheath around the plumule/stem tip

A flower having all the whorls of principal parts: sepals, petals, stamens and pistils

A leaf blade that is divided into separate leaflets

A hard and dry part that is the fruit of a pine tree or other evergreen plant and contains many seeds.

A plant species that does not flower and instead bears cones (or strobili)

Bearing cones or strobili.

A root that can shorten itself, pulling the plant deeper into the soil. They typically have a wrinkled surface that serves for expanding and contracting

A short, solid, underground stem having thin, papery leaves that surround a bud/meristematic region, such as an

A small corm that arises from the base of a larger corm, generated by asexual reproduction

The inner whorl of the flower's perianth and the collective terminology for all of the petals of a flower; typically colored, petals separated or joined (connate), and commonly advertising a flower's sexual readiness

In roots and stems, the tissue between the stele (primary vascular structure and tissues) and the epidermis

seed leaf; embryonic leaf; the first leaf or one of the first pair of leaves to develop in a seed plant. Cotyledons, when they emerge with seedling shoot, do not look the same as the plant’s “true leaves,” which develop after germination.

The hollow or pithy stem which bears the inflorescences/flower heads, found in grasses, sedges, and rushes

A cultivated variety of a plant that has been deliberately selected for specific desirable characteristics (such as the colour and form of the flower, yield of the crop, disease resistance, etc.).

The cupule holds and protects the seed during its growth and maturation. In some genera it only partly encloses the single nut, while in others, it fully encloses the two or more nuts, and splits open at maturity into four valves to release the nuts. The cupule is covered by numerous scales. In some species the scales are developed into sharp spines, giving the nut protection from squirrels and other seed predators.

The waxy, waterproof layer on the surface (and covering the epidermal cell layer) of plant leaves and stems

Falling off, and not persistent (such as plant leaves from a non-evergreen plant)

Opening at maturity or ripeness, to discharge contents (such as pollen, seeds or spores)

Refers to the epidermis, or skin

A tool provided to determine the identity of an entity of the natural world (plants, animals, rocks, fish, etc.) in which an organized series of choices presented in sequence, using two choices for each step, narrows down the identity of the individual based on its physical characteristics until a specific name can be applied.

A flowering plant species having two cotyledons, or seed leaves. Typically the seed leaves have a different shape than the "true" leaves, which are the typical shape for the plant species.

The intermingling of molecules of a fluid due to random motion.

Finger-like; lobed or veined and radiating from a common point, or divided with the units arising from a common point.

Having two forms or distinct morphological variants, such as when a plant species has two forms of leaves or two forms of fruit.

Flowers imperfect (unisexual), and having male and female flowers occurring on separate plants.

A temporary, inactive phase when growth and development stop, but potentially will become active following the necessary seasonal or environmental stimulus.

A fleshy or pulpy, one-seeded fruit that has developed from one flower having a single ovary, and the seed has a hard or stony endocarp (the pit) (such as cherries, peaches, plums). A drupelet is a very small drupe.

The embryonic stem of a seedling above the cotyledons and below the first true leaves.

The "skin" or outermost layer of cells of a non-woody plant organ (stem, leaves, roots).

a flower's ovary position when located below the attachment of the sepal, petal, and stamen whorls

A plant or plant species which grows upon another plant, but does not draw water or nutrients from that plant.

A plant or plant species that retains green leaves throughout the winter; is not deciduous.

A tight bundle or cluster.

A female cone (megasporangiate strobili) of a conifer that supports and protects the ovules (future seeds) of the plant.

A pistillate flower, with or without a perianth, that has only functioning female reproductive parts, or if male reproductive parts (stamens) are present, they are non-functioning.

The union of male and female gametes, following pollination in seed plants.

A root system with no prominent central axis, branches spread in all directions and all branches of similar thickness (such as in grasses and other monocot plants).

structure of a flower that supports the anthers (the stalk)

Flagging tape is a non adhesive marking ribbon used for surveying, mapping, tagging, roping off areas or any other marking application. For the purpose of phenological monitoring, flagging tape can be used to identify plants, or groups of plants, for regular observation. It can also be used to mark places where animals of interest have been observed. On more robust plants such as full-grown trees, flagging tape can be wrapped around trunks or branches. On younger plants, or where there is no suitable vegetation, a twig or rod is usually inserted in the ground, and the tape is usually applied at the distal end, resembling a conventional pole and 'flag.'

The process of growing feathers (for a bird).

A young bird that has recently acquired its flight feathers.

A small, individual flower, usually one in a dense cluster - such as in a grass spikelet or in a flower head of the Asteraceae family (daisies, dandelions, thistles, sunflowers).

The organ of a plant that facilitates reproduction. Responsible for attracting pollinators.

An inflorescence of tightly clustered florets/flowers, such as a capitulum (daisies, dandelions, thistles, sunflowers), or grass spikelets in an inflorescence.

A dry, dehiscent, many seeded fruit that has developed from one flower having a single-celled ovary, and splits open along one seam at maturity (such as milkweed).

Herbaceous (non-woody) flowering plants that are not graminoids (grasses, sedges and rushes).

The stage of growth of a forest or woodland; e.g., old growth (primary) and second or third growth (regrowth after disturbance/cutting).

The mature, ripened ovary of a seed plant, and the structures that are attached, accompany and ripen with the ovary.

An anther within the stamen that produce, mature, and release pollen (versus a non-functioning organ; in some plant species the flowers might typically house non-functioning, sterile male parts).

An ovary within the pistil that produce seeds (versus a non-functioning organ; in some plant species the flowers might typically house non-functioning, sterile female parts).

The ground tissue of plants contains three main cell types called parenchyma, collenchyma, and sclerenchyma. These cells types primarily support storage, mechanical support, but can also serve for food production in the photosynthetic cells, or serve in wound healing and regeneration, depending on which class of cells they belong to.

A protuberance, appendage, or other structure that secrets substances, sticky or oily.

Where the tissues of one plant are aligned with the tissues of another to create a joined plant; they will grow together if properly processed.

Plants or plant species that have similarities to the grasses (long, thin leaves; inconspicuous, non-showy flowers grouped into inflorescences/seed heads that are also non-showy; small grain-like fruits) although their anatomy may differ.

The ground tissue of plants contains three main cell types called parenchyma, collenchyma, and sclerenchyma. These cells types primarily support storage, mechanical support, but can also serve for food production in the photosynthetic cells, or serve in wound healing and regeneration, depending on which class of cells they belong to.

A seed plant that does not flower - in which the ovules are not contained within an ovary, and are "naked"; the ovary maturing to a seed protected by a surrounding cone or fleshy appendages.

A classification of the ecological and environmental characteristics of the place in which an organism, population, or species occurs or is typically found.

A specialized, modified root of parasitic plants that penetrates into a host plant and functions to acquire necessary nutrients from the host plant they attached themselves to.

A plant species that is parasitic but also partially photosynthetic, thus acquiring nutrients from the host plant but also making and supplying some of their own nutrients.

A plant or plant species having little or no woody tissue; but also refers to a perennial plant which dies back to its roots each year during winter, and resprouts and grows when the environmental conditions are acceptable.

A berry-like fruit, with pulpy sections inside, and having a tough/leathery rind outside (such as citrus fruits).

A scar on a seed indicating its point of attachment to the ovary.

A berry-like fruit that has developed from one flower having many ovaries - consisting of an enlarged and globose hypanthium that surrounds and encloses many achenes (such as with roses).

A plant that is completely parasitic on other plants with virtually no chlorophyll.

a flower's ovary position when located above the attachment of the sepal, petal, and stamen whorls

A flower having only one set of sexual organs (unisexual), either stamens or pistils (male or female).

A flower lacking one or more whorls of principal parts: sepals, petals, stamens or pistils.

Not opening upon maturity and ripening along its sutures (seams) or pores.

a flower's ovary position when located below the attachment of the sepal, petal, and stamen whorls

The flowering part of a plant; a group or cluster of flowers arranged on an axis/stem that is composed of a main stalk, and often having a complex arrangement of branches.

A group or cluster of fruits arranged on an axis/stem that is composed of a main stalk, and often having a complex arrangement of branches. An infructescence is a result of an inflorescence of flowers successfully maturing to fruit.

Insect-eating - by way of trapping and digesting them for nutrients.

The portion of a stem between two nodes.

(involucre) referring to tissue or a structure that surrounds and/or supports a cluster of flowers, such as the layers of phyllaries that surround a flower head in the daisy family (Asteraceae)

A whorl of bracts subtending a flower or flower cluster, such as for sunflowers.

An immature phase.

The expanded, leafy portion of a leaf or frond, which can be one entire unbroken leaf (simple) or a highly dissected and divided leaf (compound).

The newly hatched, earliest stage of any of various animals that undergo metamorphosis, differing markedly in form and appearance from the adult. Caterpillars are the larval form or larvae (pl) of butterflies and moths.

As pertains to stems: borne along a side. A side shoot or bud; typically situated in the axil at a stem node - lateral buds are typically axillary.

A method of propagating a plant in which its stem is induced to send out roots by surrounding a section of it with soil while still attached to a parent plant; natural layering can occur when the stem makes contact with the soil and spontaneous rooting occurs (such as when young trees are pushed over by snow, rock, or soil slides).

The flat and, typically, green part of a plant that constitutes foilage and is responsible for food production through photosynthesis. Needles on certain plants are also leaves.

The base of the leaf, near the petiole. Each plant species has specific characteristics for the leaf base that can help with identification.

The expanded, leafy portion of a leaf or frond, which can be one entire unbroken leaf (simple) or a highly dissected and divided leaf (compound). Each plant species has specific characteristics for the leaf blade that can help with identification.

The area on the outside of a grass leaf where the leaf blade meets the leaf sheath. Each grass species has specific characteristics for the leaf collar that can help with identification.

The edge of the leaf blade/lamina. Each plant species has specific characteristics for the leaf margin that can help with identification.

An imprint or scar left on stem tissue at the separation/breaking off of the leaf petiole from the plant stem/branch. Left once a leaf drops off from the stem of a plant.

The leaf base that surrounds the grass stem/culm and is attached to the upper leaf blade/lamina. Each grass species has specific characteristics for the leaf sheath that can help with identification.

A dry, several-seeded fruit that has developed from one flower having a single-celled ovary, and splits open along two seams at maturity (such as peas, beans); often a long pod. Mostly dehiscent, but some species being slowly-dehiscent, with a few species' fruits being indehiscent.

In grasses, the lower bract which, with the palea (upper bract), encloses a flower's/floret's reproductive organs. Each grass species has specific characteristics for the lemma that can help with identification.

A slightly raised, often lens-shaped area on a stem surface that allows exchange of gases.

The series of stages through which a living thing passes from the beginning of its life until its death.

A tongue or strap-shaped organ; in grasses and some sedges, an appendage that arises from the inner surface of a grass leaf where the blade/lamina meets the leaf sheath, thus it is inside of where the collar region is located on the leaf. Each grass species has specific characteristics for the ligule that can help with identification.

A dehiscent legume, several-seeded fruit that has developed from one flower, which narrows/constricts and is jointed between its seeds, drying and splitting apart at maturity into one-seeded segments, each having two seams.

A male cone (microsporangiate strobili) of a conifer that supports and protects the pollen of the plant.

A staminate flower, with or without a perianth, that has only functioning male reproductive parts, or if female reproductive parts (pistils) are present, they are non-functioning.

An phase in some plant species where leaves/needles take on a different shape (morphology) as the perennial plant ages. This species have "dimorphic" leaves. Some junipers fit into this category, as do some broadleaf species (Hedera helix (English ivy), Ficus pumila (creeping fig)).

A bract or modified leaf tissue that supports the megasporangium or developing ovule (in the case of gymnosperms - such as the bract of a pinecone/seedcone).

Undifferentiated cells in actively dividing plant tissue, found in the zones where growth takes place - such as at the tips of shoots and roots (apical), in buds and nodes of stems (apical), along grass leaves and stems (intercalary), in cambium (vascular and cork), and in a layer of cells in roots (pericycle)

A type of habitat with a moderate or well-balanced supply of moisture, i.e. a mesic forest, a temperate hardwood forest, or dry-mesic prairie.

Conventionally described as data about data, metadata can be more accurately defined as structured information that describes, explains, locates, or otherwise makes easier to use or manage an information resource.

A minute opening on the ovule through which the pollen tube usually enters; the scar upon a seed which was the opening in the ovule

A bract or modified leaf tissue that supports the microsporangium or developing pollen (in the case of gymnosperms - such as the tiny bract in pollen cone)

The central or principal rib of a leaf

The central or principal vein of a leaf

A plant species that flowers and produces fruit just once and then dies (its typical life cycle); can be applied to annuals, biennials, and perennials

plant that reproduces one time and then dies.

A plant species that has a single seed leaf (cotyledon)

A plant or plant species that has separate male/staminate and female/pistillate flowers (imperfect flowers (unisexual)) that occur on the same plant

The study of an organism's form and structure

A fruit that has developed from more than one flower, in which the flowers are tightly clustered, and mature into a tight cluster of individual fruits (such as mulberry, pineapple, fig, osage orange). This differs from an aggregate fruit which derives a single flower. (Fig is a rather unusual inflorescence and fruit, see synconium.)

A bud which lacks bud scales, with hairy, sticky, or no protective covering. Naked buds occur in two types of plants, those with naked winter buds and those with naked/uncovered resting buds of warmer climates.  

The National Phenology Database is the SQL database in which the USA-NPN stores contemporary phenology data and allows for integration with historic and other contemporary efforts to observe the natural environment.

The record of not seeing an animal of study or observing that a phenophase is not occurring. Negative data is just as important as sightings of animals observing phenophase occurrence.

The specific part or segment of a habitat, or relational position in an ecosystem, occupied by an organism

An adventitious root that arises from a node, such as the node of a stolon/runner that will anchor new growth and initiate new plants

The location on a plant stem where buds (leaves, flowers, stem branches) initiate

Refers to plants or plant species having no vascular tissues or vessels to carry water or nutrients, etc., such as mosses, fungi, algae

Tissue within an ovule in which the embryo sac develops

A dry, indeshiscent, one-seeded fruit that has developed from one flower having a single ovary, and the ovary wall becomes tough and hard at maturity. A nutlet is the same but very small.

An observation represents the full suite of phenophase responses for an individual plant or species of animal, at a site, on a given day. So, if you reported observations on three red maples, a robin and a bumblebee, today, you'd have made five observations (in the way that we're defining them here).

A YES or NO answer reported for each individual phenophase within a suite of phenophases per species.

A short, prostrate shoot arising from the base of a plant

Plants or plant species that display an opportunistic response to environmental variations in resource availability, such as species that leaf out when water is available and drop their leaves when stressed - repeatedly, or flowering unpredictably a second time later in the season when water is available during the warm months

Leaves and branches arranged along a twig or shoot in pairs, opposite each other at a single point (stem node) along a stem or axis

The spotaneous diffusion of liquid through a semipermeable membrane (such as a cell wall) in a direction that will equalize solute concentrations on both sides of the membrane. Describes the physical process in which any solvent moves, without input of energy. This is the process by which water is drawn from the soil up into the roots of a plant and transported, and moved in and out of cells (compare with active transport).

The part of the pistil that contains the ovules

Describes the position of the ovary in a flower relative to the whorls of the perianth (calyx/sepals and corolla/petals). A superior ovary describes an ovary that sits above where the perianth is attached to the floral structure; an inferior ovary describes an ovary that sits below the point of attachment of the perianth and stamens - and are attached at the top of the ovary, with the exposed style and stigma ; a perigynous ovary describes an ovary that is surrounded by floral parts (a calyx tube) that is attached to the perianth and stamens around the ovary, but not attached - making the ovary appear more or less half exposed .

The haploid body which, after fertilization, becomes a seed/propagule

In grasses, the upper bract which, with the lemma (lower bract), encloses a flower's/floret's reproductive organs. Each grass species has specific characteristics for the palea that can help with identification.

Having three or more lobes or veins arising from a common point (such as with a leaf)

A leaf which is divided into smaller leaflets, those leaflets originating from a single point of attachment, similar to the fingers on a hand

A leaf blade having the principal veins radiate out from a single point, most commonly where the leafstalk/petiole ends, and diverge out toward the edge of the leaf

A branched, racemose inflorescence - that is, an inflorescence with pedicellate lateral flowers, or spikelets (grasses) - in which the lateral branches are also branched.

A non-mutual relationship in which one organism depends on another for its nutrients, or other services, and benefits at the expense of the other (its host)

A flower stalk of a single flower, or grass spikelet, within an inflorescence; the stem supporting the entire inflorescence is called a peduncle

A primary flower stalk, supporting a solitary flower or an entire cluster of flowers (inflorescence)

A fleshy, several-seeded fruit that has developed from one flower having a single ovary divided into several carpels, which develops a firm or tough rind as it matures (such as a melon, squash, cucumber).

A plant or plant species whose life cycle lasts for three or more years

Describes a flower having both pistil and stamens - female and male reproductive organs; bisexual

Collectively, the calyx (all sepals) and corolla (all petals), or if similar in appearance the tepals, of a flower

The wall of a fruit.

a flower's ovary position with the sepal, petal, and stamen whorls attached to a surrounding cup

A modified leaf in the whorl of flower parts that surround the whorls of the reproductive parts (stamens and the pistil). Typically they are colored and showy so as to attract and guide their pollinators. Collectively, all of the petals are called the corolla.

The stalk of a leaf, that attaches a leaf blade to the plant stem

A precisely defined point in the life cycle of a plant or animal, generally marking the start or end point of a phenophase. The occurrence of a phenological event can be pinpointed to a single date and time (in theory, if not in practice). Examples include the opening of the first flower on a plant, the end of leaf fall on a tree, the first appearance of a particular songbird species in spring, or the start of fish migration up-river to spawn. (Note: The definition of the term “phenological event” has not yet been standardized and varies among scientists. The definition presented here reflects our usage of the term on the USA-NPN website.)

A vegetative or reproductive phase in a plant's life cycle, such as the opening of leaf buds or the release of pollen from flowers

The state of one or more phenophases for an individual or species at a given moment. Phenological status could include but is not limited to measures of the state of flowers, leaves, and fruits for plants or migration, breeding, and development for animals. For example, the phenological status of a plant might be: has flowers and unfolded leaves; does not have ripe fruits. For birds, an example might be: is present, is an adult, and is calling; is not building or sitting on a nest.

Phenology refers to recurring plant and animal life cycle stages. It is also the study of these recurring plant and animal life cycle stages, especially their timing and relationships with weather and climate.

An observable stage or phase in the annual life cycle of a plant or animal that can be defined by a start and end point. Phenophases generally have a duration of a few days or weeks. Examples include the period over which newly emerging leaves are visible, or the period over which open flowers are present on a plant. (See also phenological event) (Note: The definition of the term “phenophase” has not yet been standardized and varies among scientists. The definition presented here reflects our usage of the term on the USA-NPN website.)

The food/sugar conducting tissue in vascular plants, distributing the photosynthetic products within the plant

The manufacturing of food/sugar in plants, some algae and cyanobacteria - by converting light energy to chemical energy and storing it in the bonds of sugar. Carbohydrates are synthesized from carbon dioxide and water, with oxygen released as a by-product.

An individual bract under a flower head of a plant, within the involucre, such as occurs especially in, but not exclusively, the Asteraceae plant family - in daisies, dandelions, sunflowers, thistles, asters, etc. 

Having two rows of branches, lobes, leaflets, or veins arranged on either side of a common axis. The word "pinnate" means "like a feather", which might help you to visualize its structure/architecture.

A leaf which is divided into smaller leaflets, those leaflets arranged on each side of the leaf's central stalk/rachis (axis). A pinnate leaf can either be even-pinnate or odd-pinnate, indicating whether or not a terminal leaflet exists: even-pinnate leaves have pairs of leaflets attached along the leaf's central stalk/rachis (axis) with no terminal leaflet, although may occasionally have a tendril (therefore an even number of leaflets in total); odd-pinnate leaves have a terminal leaflet at the end of the leaf's central stalk/rachis (axis) along with pair(s) of leaflets attached along the leaf's rachis (therefore and odd number of leaflets in total). A bipinnately compound leaf is twice pinnate; a leaf blade divided into leaflets and having twice-diverged branching.

A leaf blade having conspicuous lateral veins which diverge from the midvein towards the leaf margin and are approximately parallel to one another

The female reproductive part of a flower made up of the ovary, style (stalk) and stigma (sticky tip that receives pollen).

A female flower, with or without a perianth, that has only functioning female reproductive parts, or if male reproductive parts (stamens) are present, they are non-functioning

The spongy, central tissue in some twigs, stems, and roots

A small plant, usually one produced vegetatively (asexually), from a parent plant 

A specialized, erect root (aerial) in certain aquatic plants that protrudes above the soil or water surface and has many lenticels, which supports gas (oxygen, etc.) exchange

A mass of microspores in a seed plant, usually appearing as a fine dust. Pollen grains are transported (typically by wind, water, insects or animals) from a stamen to a pistil, where fertilization occurs.

The conical, pollen-bearing unit of a conifer (male strobilus)

The slender tube that grows from pollen grain and holds the sperm, penetrates and delivers the sperm to the ovule

The release and transfer of pollen from the anther of the flower to a stigma of a flower, sometimes within one plant (self-pollination) or from one plant's anthers to the stigma of a different plant (cross-pollination)

Having more than two forms or distinct morphological variants, such as when a plant species has three forms of leaves - as with Sassafras

A fleshy or pulpy, several-seeded fruit that has developed from one flower having a single ovary divided into several carpels surrounded by a hypanthium/receptacle from flower parts which then becomes fleshy/pulpy as it matures (such as an apple). (see ovary position - perigynous - for further information)

The portion of the plant embryo in a seed below the cotyledons that will develop into the primary root

An adventitious root that arises from a stem that provides support for a plant (aerial)

An adventitious root that arises from a node, such as the node of a stolon/runner that will anchor new growth and initiate new plants

Any unit or structure having the capacity to generate a new plant, whether through sexual (such as with seeds) or asexual (vegetative) reproduction. This includes seeds, spores, and any part of the vegetative body capable of independent growth if detached from the parent plant

An often-modified, basal pair of leaflets of a compound leaf appearing very close to the plant stem, close to where stipules might occur

An inflorescence that has one central stalk/axis (i.e. no branching) with lateral flowers or flower clusters, or spikelets (grasses), that have pedicels.

The axis (stalk) within a grass or sedge spikelet. Further, the stalk of a grass spikelet is called a pedicel; the primary axis of the entire grass inflorescence is called a rachis.

The main stalk/axis of a flower cluster (inflorescence) or seed head (grass inflorescence), or the main leafstalk within a compound leaf

In a seed, the portion of the embryo below the cotyledons that will form the roots

A vertical row along an axis such as a plant stem, as with leaves. When you sight along the length of a branch stem, from the tip end, if it appears there are two rows of leaves, either opposite or alternate, the branch is 2-ranked; if three rows, it is 3-ranked, etc.

The more or less thickened portion at the top of a flower stalk (peduncle or pedicel) to which the floral organs or clustered florets (in the case of daisies, etc. (Asteraceae family)) are attached. For those familiar with artichokes, the artichoke heart is the flower's receptacle.

The regional plant species component of the USA-NPN Plant Phenology Program consists of a set of ~200 native or introduced plant species that have more localized distributions than calibration species, or that are particularly important in certain locales or regions of the nation in terms of ecological processes, biological diversity, conservation, economics, or human culture.

Veins are branched repeatedly, forming a net-like pattern

A horizontal, modified, underground root-like stem of a plant, often having adventitious roots and shoots from its (stem) nodes and having scales subtending the buds or shoots at its nodes or scale scars, and typically thick, fleshy or woody

The part of a plant that grows underground, gets water from the ground, and holds the plant in place.

A thimble-like covering which protects the growing root tip (meristematic region) on plant roots

The end region of a root, including the root cap, where many phases of cell development are taking place, from the meristematic regions where cell division is occurring to the zone of elongation and zone of maturation, where cells are differentiating into different tissues and the root is developing root hairs

A dense, radiating cluster of overlapping leaves (or plant organs) at or near ground level

Leaves arranged into a basal rosette, with a very short or lacking stem

A reddish brown or brownish red color, such as that of rust or oxidized iron.

A dry, indeshiscent fruit that has developed from one flower having a single ovary divided into one-seeded carpels, each having a wing at maturity

A plant, lacking chlorophyll, that lives on dead, organic debris. Certain fungi or bacteria also fit in this classification

a modified or rudimentary leaf, such as those protecting buds; in the case of conifer cones, a sporophyll (a modified leaf) is often referred to as a scale—onto which the reproductive parts are positioned

A dry, several-seeded fruit that has developed from one flower having a single ovary divided into several fused carpels, and splits into one-seeded, indehiscent segments (between carpels) when mature.

As occurs in dicot plants and gymnosperms. The thickening/expansion of a woody plant axis (added girth) through the activity of lateral meristems (the vascular cambium in stems); the end result is increased amounts of vascular tissue, such as added tree rings

The ripened ovule - a small embryonic plant enclosed in a protective covering called the seed coat, usually with some stored food (the endosperm)

The conical, seed-bearing unit of a conifer (female strobilus)

An inflorescence of tightly clustered florets/flowers, as in grass spikelets arranged in various larger displays

A plant that loses all of the leaves in winter only if it is cold enough

A primary root

The growth phase in a plant or plant part (as a leaf) from full maturity to death.

The process of biological aging in a plant or plant part (such as a leaf) from full maturity to deterioration and death

A modified leaf in the outermost whorl of flower parts that surround the whorl of petals. When the flower is in bud, they cover the flower and then open first. Typically they are colored green, but occasionally are similar to the petals (and then called tepals). Collectively, all of the sepals are called the calyx.

Attached directly, without a stalk, such as a leaf without a petiole/leaf stalk

Sun leaves and shade leaves are common in plant canopies, with sun leaves located on the top and outer, unshaded perimeter of the plant and shade leaves located on the shaded sides of the plant, under the sun leaves within the canopy.
Shade leaves receive less sunlight (photosynthetically active radiation) than sun leaves. As a result of their position within a canopy, individual leaves respond by developing slightly differently (called plasticity) but suited to their position within the canopy: morphologically, anatomically and metabolically. All this leaf variation, within one plant, results in maximizing a plant’s net rate of energy capture.
Shade leaves differ morphologically by being larger, less deeply lobed (if the species has lobed leaves), and thinner, and can have a deeper green coloring and a different texture than sun leaves on the same plant. Anatomically, sun leaves are thicker by having more or thicker palisade mesophyll cell layers with longer cells, a less developed spongy mesophyll, and a thicker cuticle than shade leaves.  Shade leaves contain more chlorophyll (chloroplasts) within their thinner layer of mesophyll cells, resulting in an increased ability to harvest sunlight at low radiation levels.

A stubby branchlet (short, slow-growing) with densely crowded leaves, nodes, and leaf scars, and potentially, flowers and fruit. (Fruiting spur: a short twisted branch which flowers and produces fruit)

A dry, dehiscent, elongated fruit, typically more than twice as long as wide, formed from one flower having a single ovary divided into two carpels, separated by a partition (septum) that bears the ovules/seeds; generally, the carpels separate when ripe, although a few separate between seeds along joints (plants of the mustard family). (A silicle is a short silique, no more than twice as long as broad.)

A fruit that has developed from one flower with a single pistil having one carpel/ovary or several fused carpels/ovaries

A leaf with an undivided lamina/blade

An unbranched inflorescence that has one central stalk/axis with lateral, sessile (i.e. no pedicels) flowers or spikelets (grasses).

Can refer to a small spike or secondary spike, but is also the most basic floral unit in the grass family.  A whole grass spikelet generally consists of 2 glumes (an upper glume and a lower glume) situated below one to many grass flowers/florets that alternate along the rachilla (the main spikelet stem/axis).  Depending on a given species, spikelet parts can be missing and florets can be unisexual.

The basic form of grass and sedge flower clusters; where one or many small flowers/florets attached to an axis are subtended by two bracts (glumes)

The reproductive cell in cryptogams (plants and plant-like organisms that lack flowers and do not reproduce by seeds) which in function corresponds to a seed but is haploid (has half a set of chromosomes) - unlike a seed that is a product of sexual reproduction and has a full set of chromosomes

A leaf-like organ upon which one or more sporangia are produced and supported.

A short shoot (short, slow-growing) having densely crowded leaves, nodes, leaf scars, and potentially flowers and fruit

The male reproductive part of a flower made up of a filament (stalk) and anthers (contain pollen).

A male flower, with or without a perianth, that has only functioning male reproductive parts, or if female reproductive parts (pistils) are present, they are non-functioning

The main trunk of a plant, or the primary axis that develops buds and shoots instead of roots.

The portion of a pistil (often at the top) - that receives pollen - and once received can promote (or restrict) the growth of the pollen tube to initiate the process of fertilization.

An adventitious root that arises from a stem that provides support for a plant (aerial)

An appendage, often leafy, at the base of a leaf petiole, mostly appearing in pairs, one on each side of the petiole

A specialized, slender, horizontal, elongate, creeping stem initiating from the base of a plant, and having minute leaves at its nodes, also rooting at the nodes, and developing new plantlets/plants that will eventually root and separate from the mother plant (a colonizing organ that enables a plant to reproduce, producing new clone plants that may surround it)

Leaves of a plant specifically modified for storage of energy (generally in the form of carbohydrates) or storage of water, such as the storage leaves found in bulbs

Roots that function to store plant nutrients/food

A cone-like cluster of sporophylls on an axis, such as a pinecone

The portion of the pistil (female flower reproductive organ) connecting the stigma to the ovary, usually narrow

The surface on or material in which a plant or animal lives

Juicy or fleshy, such as a plant having fleshy stems or leaves

A shoot originating from below ground, as from a root or lower part of a stem

Sun leaves and shade leaves are common in plant canopies, with sun leaves located on the top and outer, unshaded perimeter of the plant and shade leaves located on the shaded sides of the plant, under the sun leaves within the canopy.
Shade leaves receive less sunlight (photosynthetically active radiation) than sun leaves. As a result of their position within a canopy, individual leaves respond by developing slightly differently (called plasticity) but suited to their position within the canopy: morphologically, anatomically and metabolically. All this leaf variation, within one plant, results in maximizing a plant’s net rate of energy capture.
Shade leaves differ morphologically by being larger, less deeply lobed (if the species has lobed leaves), and thinner, and can have a deeper green coloring and a different texture than sun leaves on the same plant. Anatomically, sun leaves are thicker by having more or thicker palisade mesophyll cell layers with longer cells, a less developed spongy mesophyll, and a thicker cuticle than shade leaves.  Shade leaves contain more chlorophyll (chloroplasts) within their thinner layer of mesophyll cells, resulting in an increased ability to harvest sunlight at low radiation levels.

a flower's ovary position when located above the attachment of the sepal, petal, and stamen whorls

A fruit that has developed from more than one flower, in which the flowers were tightly clustered, and matured into a tight cluster of individual fruits - yet these flowers - ovaries/fruit are borne inside of the hollow, inverted receptacle (such as fig). The fleshy fruit consists mostly of receptacle tissue.

A root system with a prominent central axis, having the main root axis larger with smaller branches radiating from it

A taxon is a group (plural: taxa) is a group of (one or more) organisms. A taxon usually, although not always, reflects presumptive evolutionary (phylogenetic) relationships.

(From the Glossary of the International Code of Zoological Nomenclature:) "A taxonomic unit, whether named or not: i.e. a population, or group of populations of organisms which are usually inferred to be phylogenetically related and which have characters in common which differentiate the unit (e.g. a geographic population, a genus, a family, an order) from other such units. A taxon encompasses all included taxa of lower rank and individual organisms. [...]"

Someone who studies the science or technique of classifying, in this case, plants

A slender, clasping, twining, outgrowth of the stem that aids in support of climbing plants

Whorls of the perianth of a flower in which the sepals/calyx and petals/corolla are undifferentiated - and identical or almost identical in appearance - such as with tulips and lilies and magnolias

The top or tip of a structure, organ, such as a leaf or stem (and the point farthest from the point of attachment)

A fixed path in a given area along which one observes and records occurrences of plants or animals of study

The release/emission of water vapor from plant leaves (primarily through stomata) and stems into the atmosphere

A modified and specialized leaf designed to function as a trap, such as a Venus Fly-trap leaf that closes in half upon a receiving a trigger/stimulus and trapping an insect that it will digest for nutrients

Fine outgrowths or appendages on plants. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.

Having three leaves, or leaflets, or similar structures

A leaf having three leaflets

The leaves typical of a plant species that emerge subsequent to the cotyledons (which are often shaped differently)

A thickened and short subterranean stem having numerous nodes and buds (in white potatoes - the "eyes") and functioning for food storage

A swollen, modified root that has thickened for nutrient storage, such as a sweet potato and cassava (which has no "eyes" (nodes or buds)

An inflorescence in which the pedicels or stalks of the flowers or clusters of flowers arise from a common point, or near one point.

The USDA Hardiness Zone Map divides North America into 11 separate zones; each zone is 10°F warmer (or colder) in an average winter than the adjacent zone.

A dry, indeshiscent, one-seeded fruit that has developed from one flower having a single ovary, and the ovary wall becomes more or less bladdery or inflated at maturity.

Conducting tissues, as in xylem and phloem, and plants that have these tissues (versus non-vascular plants)

A conducting strand/cluster of tissues (xylem and phloem for conducting water, nutrients, photosynthates/food) in a plant

Asexual reproduction in which the propogated plant(s) has the same genetic makeup (identical chromosomes) as the mother plant, and in which no genetic material/DNA was exchanged

The arrangement and pattern in which the veins occur in a leaf (specific to species)

An arrangement of 3 or more leaves that attaches at a node, circling the stem

The transport, by wind, of pollen from a flower's anther to another flower's stigma

leaf or flower buds that are in a dormant phase during the coldest season and are protected by bud scales or dense hairiness

The specialized vascular plant tissue that functions in the transport/conduction of water and minerals upward through the plant