Acute: Terminating in a sharp point with more or
less straight sides.
Acuminate: Gradually tapering to a sharp point and forming concave sides along the tip.
Adventitious root: Root arising from part of plant other
than root; usually produced laterally on aerial stems.
Aerial roots: Roots that grow above ground and are
not covered by soil or water.
Algae (singular Alga): A simple and primitive group of
photosynthetic organisms formerly placed in the Plant Kingdom
but now put in Kingdom Protista. Many are single-celled, but
others are multicullular, including algae known as seaweeds.
Alluvial: Soil composed of sand, clay or silt which has been
dispersed by water.
Alternate: Leaves arranged singly along a twig or a shoot,
and not in whorls or opposite pairs.
Angiosperms: The flowering plants. Plants that produce
flowers in which the egg cells (ovules) are covered by a tissue
called the ovary. The ovules develop into seeds and the ovary
into a covering called the fruit.
Annual: A plant that emerges from seeds and goes through
its entire life cycle in just one growing season.
Anther: the pollen-producing part of a stamen.
Anthophyta: Within the Plant Kingdom, the division of
flowering plants. [AV]
Asexual reproduction: Reproduction that does not depend
on the coming together of male and female sex cells.
Awl-shaped: Short, narrowly triangular, and sharply
pointed like an awl.
Axillary bud: Buds in the axils of leaves or leaf scars.
Basal: Positioned at or arising from the base, as leaves
arising from the base of the stem.
Biennial: A plant that takes two growing seasons to go
through its life cycle.
Bipinnate: Twice pinnate; with the divisions again
Bole: The main stem or trunk of a tree.
Botany: The scientific study of plants.
Branchlet: A small branch.
Bract: A modified leaf which is part of a flower.
Bryophytes: The non-vascular plants including the mosses,
liverworts, and hornworts; members of the division Bryophyta.
Bud: Immature vegetative or floral shoot or both, often
covered by protective scales and born on stems or twigs.
Bulb: A short, erect underground stem surrounded by fleshy
Canopy: The upper layer of forest, formed by interlacing
branches and leaves.
Cambium: A layer of living cells in a woody plant, such as
a tree, between the bark and the wood of the stem. The cambium produces phloem (to the outside) and xylem (to the inside). In
dicot woody plants, the xylem makes up what we call the tree's
Carpel: The female part of a flowering plant that contains
Carnivorous plants: Those that are able to digest and
absorb nutrient elements from the bodies of animals,
Catkin: An elongated flower cluster.
Chlorophyll: The green pigment in plants that harnesses
the Sun's energy during photosynthesis.
Clasping: Term used to describe a leaf with no petiole and
partly surrounding the stem.
Club mosses: Within the Plant Kindgom, primitive vascular
plants of the division Lycophyta. These plants are not true
mosses (which lack vascular tissue). In some species the spores
are born in club-like structures.
Composite: A family of flowering plants (Asteraceae or Compositae) in which the distinctive feature is that relatively
small flowers (florets) are crowded together in a dense "head". Florets come in two types: ray and disk flowers. Some species
have ray flowers only, some have disk flowers only and some have
both. Members of this family include daisy, sunflower, and
Compound Leaves: Leaves consisting of two or more blades
Cone: The reproductive organ of conifers, in which seeds
lie between protective scales.
Conifers: Vascular woody plants that bear their seeds in
cones. They are usually evergreen and have needle-like leaves.
Within the Gymnosperms, this is the division Coniferophyta.
Cordate: Heart shaped, in leaves, the notch is positioned
at the base of the petiole.
Corymb: A flat-topped or round-topped inflorescence, with
the lower pedicels longer than the upper.
Cotyledon: The first or "seed" leaf of a seed plant.
Cyme: A flat-topped or round-topped inflorescence in
which the central flower opens first.
Deciduous: Trees which loose their leaves seasonally or at
some stage of development.
Dentate: Leaves with sharp, outward-pointing teeth
surrounding the entire edge.
Dicots: Flowering plants whose embryo has two cotyledons.
Dormant: Inactive, or resting. Dormancy is a stage in
seeds and buds that prevents them from germinating or opening
in unfavorable conditions.
Downy: Covered with short, straight, soft hairs.
Elliptic: Broadest near the middle and gradually
tapering to both ends.
Entire: Leaf margins which do not have teeth or lobes.
Epiphyte: A plant that grows on the branch, stem, bark,
or leaves of another plant but makes its own food.
Escaped: Spread from cultivation and now growing and reproducing
without aid from man.
Fascicle: A small cluster or bundle, such as with conifer
Ferns: Plants of the division Pterophyta, with leaves
(fronds) often consisting of many leaflets.
Fertile: As applied to soils, rich in plant nutrients.
As applied to organisms, capable of producing offspring.
Fertilization: The joining of male and female sex cells to
form a new individual.
Fibrous roots: Fine, threadlike or slender roots.
Filament: The stalk of a stamen.
Fissures: Linear splits or cracks. Term commonly refers to bark or stems.
Flower: The reproductive organ of angiosperms; contains
male and/or female parts. The ovules are covered by a
protective tissue (the ovary).
Fronds: The leaves of ferns. Fern fronds maybe uncut (undivided), once-cut (divided into subdivisions), twice-cut
(divided into subdivisions twice-the subdivisions are
themselves subdivided), or thrice-cut (divided into subdivisions
three times-the subdivisions of the subdivisions are also subdivided!). Thrice-cut ferns are also called lacy ferns.
Fruit: The mature ovary of a flowering plant, containing
ripe seeds, plus covering tissues.
Furrowed : Deeply grooved; often used to describe tree bark.
Germination: The period when a seed or spore begins to grow.
Glabrous: Smooth, without hairs.
Glaucous: Covered with a whitish or bluish waxy coating,
as on the surface of a plum.
Gymnosperms: Vascular plants that do not have flowers
and produce naked ovules and seeds (without a covering);
include conifers, cycads, and gingko.
Hastate: Arrowhead shaped leaves, but with the basal
lobes turned outward rather than downward.
Herb: A plant with aboveground stems that live for
only one season (also called non-woody stems).
Herbaceous: Having non-woody stems.
Heartwood: The older, harder wood in the middle of a tree
trunk that can no longer transport water up to the leaves.
This wood is often saturated with decay-protecting chemicals
that also make it a different color from the outer wood.
Humus: Dark brown or black partially decomposed organic matter.
Incurvate: Inwardly curved.
Infertile: Poor in plant nutrients.
Inflorescence: The arrangement of flowers on the plant
Internode: A section or region of stem between nodes.
Keel: A central longitudinal ridge.
Labellum: The large central petal of an orchid, which
Lanceolate: AMuch longer than wide, widest below the
middle, and tapering toward the tip.
Leader: The central or primary stem of a branch or tree.
Leaf: An expanded, usually green, structure borne on
the stem of a plant. Undergoes photosynthesis and
Leaflet: a single segment or subdivision of a compound leaf.
Leaf Margin: The outer edge of a leaf.
Leaf scar: A mark on branch or twig indicating former
place of attachment of petiole or leaf base.
Legumes: Plants of the pea family (Fabaceae or
Leguminosae). In many species, the fruit is the distinctive
"legume" or pod with rows of seeds.
Linear: Long and narrow with essentially parallel sides.
Loam: Soil composed of sand, clay and organic matter.
Lobe: A rounded projection or division of a leaf.
Mangroves: Trees that grow on the shores of river deltas, estuaries and coastlines in Subtropical to Tropical climates.
Midrib: The central conducting and supporting structure
of the blade of a simple leaf or leaflet.
Monocots: Flowering plants whose embryo has only one
Needles or Needle-like leaves: Long, narrow leaves,
similar in form to the shape of a needle.
Node: Region of stem from which a leaf, leaves, or
Obovate: Inversely ovate, with the petiole attachment
at the narrower end.
Obovoid: Egg-shaped fruit with the narrow end attached
to the stem.
Obtuse: Blunt or rounded leaf tip, with the edges of
the leaf coming together at an angle greater than 90 degrees.
Opposite: Sets of leaves arranged along a twig or shoot
in pairs, with one on each side and not alternate or in whorls.
Ovoid: A three dimensional, eggshaped object (fruit).
Ovary: The part of the plant in which the female sex
cells are produced.
Ovate: Egg shaped, wider below the middle (describing
a leaf shape).
Ovule: Structure in flowering plants containing the
female sex cell (egg) that develops into a seed after
Palmately compound: Leaves with leaflets coming from
one point at end of petiole.
Palmately veined: Leaf veins spreading out from a
Panicle: A multi-branched inflorescence with flowers
maturing from the bottom upwards.
Parasite: A plant that lives on another and derives,
water, nutrients and/or organic compounds from it, such as
Pedicel: The stalk of a single flower that is part of
Peduncle: Main stalk for entire inflorescence.
Perennial: A plant that lives for many growing seasons.
All trees are perennials.
Perfect flowers: Flowers possessing both the male and
female reproductive organs.
Petiolate: With a petiole; term used to describe leaf
attachment to stem.
Petiole: The stalk of a leaf.
Photosynthesis: The conversion of carbon dioxide and
water to sugars and starches, using energy from sunlight.
Oxygen is also produced as a waste product.
Pinnae: One of the divisions of a pinnately compound leaf.
Pinnate: Compound leaves arranged on opposite sides of
an axis or rachis.
Pistil: The female part of a flower, which develops into
seeds and fruit when fertilized.
Pocosin: A raised area of wetland.
Pollen: Minute grains, usually powdery, containing the
male sex cells of gymnosperms and flowering plants.
Pollination: The transfer of pollen from an anther to a
stigma (of the same or another flower).
Polygamous: Having both perfect and unisexual (flowers possessing
one reproductive organ) flowers.
Pterophytes: Ferns; members of the division Pterophyta.
Pubescent: Covered with short, soft hairs.
Rachis: The axis or central line of a leaf or flower.
Raceme: An elongate, unbranched flower structure with
Resin: Semisolid or viscous substance secreted by
conifer wood or bark.
Respiration: The process by which living things
breakdown energy containing organic molecules in the presence
of oxygen to supply energy for growth and reproduction.
Respiration produces carbon dioxide as waste product.
Rhizoid: Rootlike structure that helps anchor mosses,
liverworts, and fern prothalli to the ground or other surface.
Some are able to absorb moisture and dissolved minerals.
Rhizome: A horizontal underground stem.
Root: The nutrient absorbing and anchoring component of
plants, usually initially developed from the radicle and
growing downward underground.
Runner (or Stolon): An above ground propagative stem,
rooting at the tip to form new plants.
Sapwood: The younger, softer wood in a tree trunk that
transports water to the leaves.
Scale: Small, often triangular, leaf or leaf-like tissue.
Scales or Scale-like leaves: Leaves in the shape of small,
flat or thickened triangles.
Serrate: Leaves with forward-pointing teeth surrounding
Sessile: without petiole; term used to describe leaf
attachment to stem.
Shrub: A much-branched woody perennial plant usually
without a single trunk.
Simple leaves: Leaves consisting of a single undivided
blade; not compound.
Sinus: A recess, cleft or gap between two lobes.
Solitary: Occurring singly and not borne in a cluster
or group, such as a solitary lily flower.
Sori: Clusters of sporangia on the undersides of fern fronds.
Spike: An elongate, unbranched flower structure with
Spine or Spine-like: A stiff, slender, sharp-pointed
structure representing a modified leaf or stipule.
Sporangia: Spore-producing structures in ferns.
Spore: A simple unit in fungi and primitive plants
consisting of one or a few cells, produced either sexually
or asexually, that can then grow into a new organism.
Stamen: A male part of a flower producing pollen.
Stamens usually consist of the pollen-bearing anther on a
stalk called the filament.
Stigma: The sticky receptive surface of the pistil, on
which pollen grains germinate.
Stipule: A leafy appendage at the base of a petiole or nearby
on the twig or stalk.
Stomata: A very small pore which allows water and air to enter
and exit a leaf.
Style: Non-ovule-bearing portion of pistil between stigma
Taproot: A single broad root.
Tendril: Long, slender, coiling plant organ, adapted for
climbing. Formed by modification of a part of a plant, such
as a stem, a leaf or leaflet.
Terminal buds: Buds found on the end of a twig.
Thorn: A sharp-pointed branch.
Transpiration: The process in which plants give off
excess water into the atmosphere in the form of water vapor.
Tree: A tall, woody perennial plant usually with a single
Trifoliate: Having three leaves or three leaflets.
Umbel: An inflorescence in which individual flower stalks
arise from a single point and are approximately of equal length.
In a compound umbel this branching is repeated.
Understory: Trees, shrubs and other plants located beneath
and in the shade of larger trees.
Vine: An elongate, weak-stemmed, often climbing annual or
perennial plant, with herbaceous or woody stems.
Whorl: An arrangement of similar anatomical parts (such as
leaves) in a circle around a point on an axis.