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Glossary - Botanical Terms

 

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Achene
A small, dry fruit that contains one loose seed and that does not split open spontaneously, e.g. sunflower seed.
Acuminate

Tapering gradually to a point at the apex.

Acute
Coming sharply to a point at the apex.
Alternate

Arranged singly at different points along a stem or axis.

Annual

A plant which grows from a seed, flowers, sets seed and dies in one year.

Anther

Fertile part of a stamen, containing pollen.

Apex

The tip or terminal end.

Apical
Describes the apex or tip.
Appressed

Pressed flat or close to the stem, not spreading.

Aril

An outer covering or appendage of some seeds.

Ascending

Rising upward gradually from a prostrate base.

Awn

A bristle characteristic of the spikelets in some grasses.

Axil

The more-or-less V-shaped angle made by the junction between a leaf and a stem or twig.

Axillary

Growing from an axil.

Basal rosette

Leaves radiating directly from the crown of the root.

Berry

A stoneless, pulpy fruit containing one or more embedded seeds, e.g. grape, tomato.

Biennial

A plant which forms leaves in the first year, produces a flowering shoot in the second year, flowers, sets seed and dies.

Bilabiate

Two-lipped.

Bipinnate

Pinnate, with pinnate leaflets.

Blade

The broad, thin part of a leaf or petal.

Bloom

A powdery, greyish coating on leaves, flowers, stems, or fruit.

Bracts

The leaf-like structures of a grouping or arrangement of flowers (inflorescence). A green leaf-like structure which has a flower in its axil, and which may remain on the plant with the fruit. Bracts vary enormously in size, shape and function.

Bud

A protuberance on a stem, from which a flower, leaf or shoot develops.

Bulb

Underground storage organ composed of fleshy, scale-like leaves.

Calyx

The sepals collectively; the external floral envelope, usually consisting of layered, fleshy leaves and membranes.

Capsule

A dry, many-seeded, spontaneously splitting fruit that arises from a compound  pistil.

Carpel

Female organ of a flower consisting of an ovary, style and stigma.

Catkin

A drooping spike of small flowers characteristic of some deciduous trees. Male catkins produce pollen; female catkins are pollinated and then develop into fruiting catkins which bear seeds. A spike-like flower cluster that bears scaly bracts and petal-less, unisexual flowers.

Cauline

Relating to or growing on a stem.

Chambered

Of pith, divided into empty horizontal chambers by cross partitions.

Clasping

Partly or completely surrounding the stem.

Claw

The narrow, curved base of a petal or sepal in some flowers.

Clone
A group of plants derived from one parent plant, identical to each other and to the parent.
Compound

Made up of two or more definable parts.

Compound pistil

A pistil made up of two or more partially or completely united carpels.

Cone

A rounded, more or less elongated cluster of fruits or flowers covered with scales or bracts.

Coniferous
Cone, bearing.
Cordate
Heart-shaped, with a sinus and rounded lobes.
Corm

A bulblike but solid, fleshy underground stem base.

Corolla

The petals of a flower, which may be separate or joined in varying degrees.

Corymb

A generally flat-topped flower cluster with pedicels varying in length, the outer flowers opening first.

Creeper

A shoot that grows along the ground, rooting all along its length.

Crenate

Having rounded teeth along the margin.

Crenulate
Having very small rounded teeth.
Culm

The hollow stem of grasses and bamboos.

Cultivar
A cultivated variety.
Cyme

A branching, relatively flat-topped flower cluster whose central or terminal flower opens first, forcing development of further flowers from lateral buds. e.g. elderberry (Sambucus).

Deciduous

Falling off each season (as leaves); bearing deciduous parts (as trees).

Decompound

Divided several or many times; compound with further subdivisions.

Decumbent

Lying on the ground but having an ascending tip.

Decurrent

Descriptive of leaves whose edges run down onto the stem.

Dentate

Sharply toothed, with the teeth pointing straight out from the margin.

Digitate

Compound, with the elements growing from a single point.

Dilated

Expanded, broadened, flaring.

Disk floret

One of the tubular flowers or florets in the center of the flower head of a composite flower such as the daisy.

Dissected

Cut into fine segments.

Doctrin of Signatures

A concept popular in the 15th century, espoused that God revealed an herb's medicinal purpose by providing special markings on the plant. There are many herbs that indeed support this theory, e.g. the leaves of the lungwort plant, an excellent treatment for upper respiratory infections and lung ailments, have spotted markings that are characteristic of delicate lung tissue. The root of the ginseng plant, an herb reputed to be good for nearly every organ system, resembles the shape of the human body.

Double

Descriptive of flowers that have more petals than normal.

Doubly serrate

Serrate, with small teeth on the margins of the larger ones.

Drupe

A fleshy fruit containing a single seed in a hard "stone", e.g. peach, date, cherry.

Entire

Having no teeth or indentations.

Evergreen

Retaining green foliage for more than one season.

Exfoliate
To peel off in shreds or thin layers, as bark from a tree.
Falcate
Sickle-shaped.
Fascicle
A close cluster. e.g. leaves of white pine.
Filiform

Long and very slender, thread-like.

Floret

A very small flower, especially one of the disk flowers of plants in the composite family.

Follicle
A dry fruit opening only along one structure and the product of a single carpel (simple ovary). e.g. peony, columbine, milkweed.
Frond

The leaf of a fern.

Fruits
The seed bearing part of a plant. Technically a ripened ovary with its adnate parts, the seed-containing unit characteristic of all Angiosperms. Different kinds of fruits include;

Berry: a juicy fruit which usually contains several seeds.

Capsule: a dry or fleshy fruit which splits open to release the seeds.

Nutlet: a hard dry fruit containing a single seed.

Pod: a long dry fruit, usually containing several large seeds, which splits open along one or  both seams to release the seeds.

Funnelform

Descriptive of a flower whose corolla tube widens gradually and uniformly from the base.

Genus
A group of species possessing fundamental traits in common but differing in other lesser characteristics.
Glabrous

Not hairy.

Glandular

Having glands, which secrete sticky substances.

Glaucous

Covered with a fine, white, often waxy film, which rubs off. e.g. the bloom on many sorts of grape.

Globose

Approximately spherical.

Grain

Achene-like fruit, but with the seed not loose.

Grooved
Marked with long narrow furrows or channels.
Hairy
Pubescent with longer hairs.
Head

A flower spike or raceme shortened to form a compact, flattened to globose cluster.

Herb

A plant that has no woody tissue and that dies down to the ground at the end of a growing season.

Herbaceous

Non-woody, herb-like.

Hirsute
Pubescent with coarse or stiff hairs.
Hesperidium

A partitioned berry with a leathery, removable rind, e.g. orange.

Hispid
With stiff or bristly hairs.
Hoary

Closely covered with short and fine whitish hairs.

Imbricated
Overlapping, as slates on a roof.
Incised

Sharply and irregularly slashed or cut.

Indigenous

Native; naturally occurring.

Indumentum
With a generally heavy covering of hair: a general term without precise connotation.
Inflorescence

Technically, the way flowers are arranged in a cluster; generally, a flower cluster.

Internode

The part of a stem or branch between nodes.

Interrupted

Descriptive of a structure, the pattern or sequence of whose elements is broken by the insertion of other elements.

Keel

Boat-shaped structure formed by the two lower petals in members of the Pea family.

Labellum

Lowermost petal of an orchid flower, often specially modified to aid insect pollination; it may be variously shaped, coloured or ornamented.

Lanceolate

Widening to a maximum near the base, broadest below the middle and tapering to a point at the apex.

Lateral

Occurring on or growing from the side (compare terminal).

Latex
Milky sap.
Leaf

A vegetative organ which, when complete, consists of a flat blade, a petiole or stalk, and (usually two) small leafy appendages at the base of the petiole.

Leaflet

A division or part of a compound leaf.

Legume

A one-celled fruit that splits along two sutures or seams, e.g. pea.

Liana

A vigorous woody vine (usually refers to tropical vines).

Linear

Long and narrow, with nearly parallel sides. e.g. blades of grass.

Lip

One of the parts in a corolla or calyx divided into two unequal parts.

Lobe

A part of division, especially when rounded, of an organ.

Lyrate

Lobed to resemble a lyre, with the terminal lobe largest and the lower lobes smaller.

Margin
The edge of a leaf.
Mature
A later phase of growth characterised by flowering, fruiting, and a reduced rate of size increase.
Milky sap
Whitish in colour, often thicker than water.
Native
Inherent and original to an area.
Needle
The slender leaf of many conifers.
Node

A point on a stem at which leaves are produced.

Nut

A hard-walled, one-celled, one-seeded fruit that does not split spontaneously, e.g. hazelnut.

Ob-

A prefix that indicates reversal of the usual orientation, e.g. oblanceolate means widening gradually from the pointed base to a maximum near the apex, which may be more or less rounded.

Oblique
Lop-sided, as one side of a leaf base larger, wider or more rounded than the other.
Oblong

Longer than wide and rounded at the ends, with nearly parallel sides for much of the length.

Obovate

Oval, but broader toward the apex; refers to leaf shape.

Obovoid
Three dimensional shape of obovate, pear shaped.
Obtuse

Rounded or blunt, approaching the semi-circular.

Opposite

Growing two to a node on opposite sides, as leaves.

Orbicular

Circular or approximately round.

Oval

Broadly elliptical. Twice as long as broad, widest at the middle, both ends rounded.

Ovate

Oval, but broader toward the base; egg-shaped.

Ovoid

Ovate.

Palmate

With 3 or more leaflets, nerves, or lobes radiating from a central point; compounded, divided, lobed, or ribbed so that the divisions or ribs spread out like fingers from a single point.

Panicle

A branching flower grouping, with branches that are usually racemes.

Papilionaceous

Descriptive of a flower whose petals are arranged to resemble a butterfly.

Parasite

Plant completely lacking green pigment and obtaining all its food from another plant (host) via specialised roots called haustoria.

Pedicel

The stalk of one flower in a cluster.

Peduncle

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

Peltate

Having a stalk attached at or near the middle.

Pendulous
More or less hanging or declined.
Perennial

A plant which lives from year to year, starting into growth again each spring. Some perennial plants are herbaceous and dies down each year, remaining dormant beneath the ground throughout the winter. Others are trees or shrubs; some lose their leaves in winter (deciduous trees), while others retain their leaves throughout the year and their growth slows down in winter (evergreen trees).

Perfect (flower)

A flower that has a full complement of male and female parts as well as floral envelopes (petals and sepals).

Perfoliate

A leaf that appears to be perforated by the stem.

Perianth

All the sepals and petals of a flower.

Pericarp
A term used by some to designate a fruit; technically, the ovary wall.
Periderm
A protective layer of corky cells.
Persistent

Remaining on the plant; not falling off readily.

Petal

One unit of the corolla.

Petiole

The stalk of a leaf.

Pinna

Plural pinnae; a leaflet or primary division of a pinnately compound leaf.

Pinnate

A featherlike arrangement; usually refers to a compound leaf with leaflets arranged on each side of a central axis.

Pinnatifid

Split about halfway to the midrib, such that the divisions are pinnately arranged.

Pinnule

One of the divisions of a pinnate leaflet in a bi-pinnate leaf.

Pistil

The female reproduction organ of a flower.

Pod

Generally, a dry fruit that splits open.

Polygamous
Bearing unisexual and bisexual flowers on the same plant.
Pome

A fleshy fruit with a central seed-bearing core, e.g. apple, pear.

Procumbent

Growing along the ground without rooting, and having ascending tips.

Prostrate

Growing flat along the ground.

Pubescent

Covered with down or soft, short hairs; a general term.

Punctate

Having translucent spots or depressions.

Raceme

An unbranched, elongated flower grouping, with individual flowers on distinct stalks.

Rays (ray florets)

The strap-like, often sterile flowers (commonly called "petals") surrounding the flower-head (disk) off a plant in the composite family, e.g. the yellow rays of sunflowers, or the purple rays surrounding the cone of purple coneflower (Echinacea).

Receptacle

The end of the stem or stalk on which some or all of the flower parts are borne.

Reflexed
Bent abruptly backward or downward.
Reinform
Kidney-shaped.
Rhizome

A perennial creeping underground portion of a stem which may look like a root; producing shoots on top and roots beneath; different from a root in that it has buds, nodes, and scaly leaves; rootstock.

Rhombic
With four nearly equal sides, but unequal angles, diamond shaped.
Rootstock

Rhizome.

Rosette (basal)

Leaves radiating directly from the crown of the root.

Rugose
Wrinkled, usually covered with wrinkles.
Runner

A thin stem or shoot growing along the ground and producing roots at the nodes.

Sagittate

Resembling an arrowhead in shape.

Samara

A winged fruit that does not split spontaneously, e.g. maple, ash.

Saprophytic

A plant (usually lacking chlorophyll) that lives on dead organic matter.

Scale

A small, usually dry leaf that is closely pressed against another organ.

Scape

A leafless flower stalk that grows from the ground.

Sepal

The individual divisions of the calyx (outer floral envelope).

Serrate

Saw-toothed, with the teeth pointing toward the apex.

Sessile

Lacking a stalk, such as a leaf or flower with no obvious stalk.

Sheath

An expanded or tubular structure that partially encloses a stem or other organ.

Shoot

A new young growth; a stem or branch and its leaves.

Shrub

A woody plant that produces no trunk but branches from the base.

Silicula

Pod-like fruit of the Cabbage family that is less than three times as long as wide; it has two halves and a persistent central partition.

Siliqua

A silicula that is more than three times as long as wide.

Silique

A term applied to the peculiar seedpod structure of plants in the mustard family.

Simple

Not compound (leaves) or branched (stems, flower clusters).

Sinuate
With a strongly wavy margin.
Sinus
The space between two lobes, segments, or divisions.
Smooth

Not rough (compare glabrous).

Solitary

Not growing as part of a cluster or group.

Spadix

A thick, fleshy flower spike (usually enveloped by a spathe), as in members of the arum family (Skunk Cabbage, Jack-in-the-Pulpit, Dragon Arum, etc.).

Spathe

A modified, leaflike structure surrounding a spadix, as in members of the Arum family (Skunk Cabbage, Jack-in-the-Pulpit, Dragon Arum, etc.).

Spatulate

Shaped like a spoon, with a narrow end at the base.

Species
A natural group of plants composed of similar individuals which can produce similar offspring; usually including several minor variations.
Spike (flower)
An un-branched, elongated flower grouping in which the individual flowers are sessile (attached without stalks).
Spikelet

A small spike, particularly one of the few-flowered spikes making up the inflorescence of a grass.

Spine
Strong and sharp pointed. e.g. spines of hawthorns.
Spore

A one-celled reproductive body produced by relatively primitive plants.

Spur

A slender, hollow projection from a petal or sepal.

Stalked bud
A bud whose outer scales are attached above the base of the bud axis.
Stamen

The pollen-bearing anthers with attached filaments (sometimes without filaments); the male organ of a flower.

Standard

Upper petal in members of the Pea family (Leguminosae); often erect..

Stellate
Star-like; stellate hairs having radiating branches or are separate hairs aggregated in star-like clusters; hairs once or twice forked often are treated as stellate.
Stipule

Appendages (resembling small or minute leaves) at the base of leaves of certain plants, often ear-like.

Striate
With fine longitudinal lines, channels or ridges.
Strigose
With sharp, stiff, straight hairs.
Strobile

A cone or cone-like structure.

Strobilus
A cone.
Style

The slender, elongated part of a pistil.

Subshrub

Somewhat or slightly shrub-like; usually a plant with a stem that is woody at the base, but mostly herbaceous.

Subtend
To stand immediately beneath.
Suture

A natural seam or groove along which a fruit splits.

Sympodial
Continuing growth by the development of an axillary bud and not the terminal bud, season after season.
Taproot

A single main root that grows vertically into the ground.

Tendril

A modified leaf or branch structure, usually filiform, often coiled like a spring, used for clinging in plants that climb.

Tepal
A segment of perianth not differentiated into calyx or corolla. e.g. tulip, magnolia.
Terminal

Occurring at or growing from the end opposite the base (compare lateral).

Ternate

Occurring in threes or divided into three parts.

Thorn
A modified twig which has tiny leaf scars and buds; can be single or branched.
Tomentose
Densely woolly, the hairs soft and matted.
Translucent
Transmitting light but diffuse enough to distort images.
Trifoliate

Having three leaves.

Trifoliolate

Having three leaflets.

Tripinnate

Descriptive of a pinnate leaf having pinnate leaflets with pinnate pinnules.

Tuber

A swollen root or underground stem or rootstock, which forms a food store for the plant.

Umbel

A flower grouping with individual flower stalks or floral groupings radiating from a central axis; often flat-topped and umbrella-like.

Undulate
Wavy, as a leaf margin.
Valve

One of the parts into which a capsule divides when splitting.

Variegated
Striped, margined or mottled with a colour other than green, where green is normal.
Variety
Subdivision of a species having a distinct though often inconspicuous difference, and breeding true to the difference.
Whorl

A circular arrangement of three or more leaves, flowers, or other parts at the same point or level.

Woolly
Having long, soft, more or less matted hairs; like wool.