Flower Growers Glossary

A

ACID SOIL

A soil which contains now free lime and has a pH or less than 6.5.

ADVENTITIOUS

Term applied to organs produced at a point where such growth would not appear naturally. Roots on an above-ground stem are an example.

AERATION

The loosening of soil by digging or other mechanical means to allow air to pass freely.

ALKALINE SOIL

A soil which has a pH of more than 7.3. Other terms are chalky and limy soil.

ALPINE

A rather vague term used to describe low-growing rockery perennials

ALTERNATE

Leaves or buds which arise first on one side of the stem and then on the other.

ANNUAL

….

ANTHER

The part of the flower which produces pollen. It is the upper section of the stamen.

ASEXUAL

Vegetative reproduction – e.g. cuttings and division.

AWL-SHAPED

A narrow leaf which tapers to a stiff point.

AXIL

The angle between the upper surface of the leaf stalk and sterm that carries it. An axillary bud arises in this angle.

B

BASAL SHOOT

A shoot arising from the neck or crown of the plant.

BASTARD TRENCHING

Another term for double digging.

BEARDED

A petal bearing a tuft or row of long hairs

BEDDING PLANT

A plant which is ‘bedded out’ in quantity to provide a temporary display.

BIENNIAL

Coming soon.

BIGENERIC

A hybrid produced by crossing two different genera – e.g. Heucherella, a hybrid of Heuchera and Tiarella.

BISEXUAL

A flower bearing both male and female reproductive organs – compare dioecious and monoecious.

BLEEDING

The abundant loss of sap from severed plant tissues.

BLIND

Term applied to a mature bulb which produces normal foliage but fails to flower

BLOOM

Two meanings – either a fine powdery coating or a flower.

BOSS

A ring of prominent and decorative stamens.

BOTTOM HEAT

Under surface heat provided in the soil by organic fermentation, electric cables or hot water pipes.

BRACT

A modified leaf at the base of a flower. A cluster of small bracts is a bracteole.

BREAKING BUD

A bud which has started to open.

BUD

A flower bud is the unopened bloom. A growth bud or eye is a condensed shoot.

BULB

C

CALCAREOUS

Chalky or limy soil.

CALCIFUGE

A plant which will not thrive in alkaline soil.

CALLUS

The scar tissue which forms at the base of a cutting.

CALYX

The ring of sepals which protect the unopened flower bud.

CAMPANULATE

Bell-shaped

CHELATE

An organic chemical which can supply nutrients to plants in a soil which would normally lock up the plant-feeding element or elements in question.

CHIMAERA

A mutation which produces two kinds of tissue – e.g one or more ‘wild’ coloured petals in a Chrysanthemum.

CHLOROPHYLL

The green pigment found in leaves which is capable of using light-energy to transform carbon dioxide and water into carbohydrates by the process known as photosynthesis.

CHLOROSIS

An abnormal yellowing or blanching of the leaves due to lack of chlorophyll.

CLOCHE

A temporary structure of glass or plastic sheets used to protect and hasten the growth of plants in the open.

CLONE

A group of identical plants produced by vegetative reproduction from a single parent plant.

COMPOSITAE

The Daisy Family , in which each flower bears ‘petals’ which are really florets.

COMPOST

Two meanings – either decomposed vegetable or animal matter for incorporation in the soil or a potting/cutting/seed sowing mixture made from peat (‘soilless compost’) or sterilised soil (‘loam compost’) plus other materials such as sand, chalk and fertilisers.

COMPOUND FLOWER

A flower composed of florets.

COMPOUND LEAF

A leaf composed of two or more leaflets.

CORDATE

Heart-shaped.

CORM

Coming soon.

COROLLA

The ring of petals inside the calyx of the flower.

CORONA

The trumpet produced in certain flowers, e.g Narcissus.

CORYMB

A flat-topped inflorescence in which all the flowers open at approximately the same time.

COTYLEDON

A seed leaf which usually differs in shape from the true leaves which appear later.

CROCK

A piece of broken flower pot used at the bottom of a container to improve drainage.

CROSS

The offspring arising from cross-pollination.

CROWN

The bottom part of a herbaceous plant from which the roots grow downwards and the shoots arise.

CRUCIFERAE

The cabbage or Wallflower Family, in which the flower bears four petals in the shape of a cross.

CULTIVAR

Short for ‘cultivated variety’ – it is a variety which originated in cultivation and not in the wild. 

CYME

A flat-topped or domed inflorescence in which the flowers at the centre open first.

D

DEAD-HEADING

The removal of faded flowers.

DECIDUOUS

A plant which loses its leaves at the end of the growing season.

DECUMBENT

A prostrate stem with an ascending tip.

DENTATE

Toothed margin.

DIBBER

A blunt-ended wooden stick used to make holes in the soil for transplants.

DIGITATE LEAF

A leaf composed of finger-like radiating leaflets.

DIOECIOUS

A plant which bears either male or female flowers. Compare monoecious.

DISC (DISK)

The flat central part of a compound flower. It is made up of short, tubular florets.

DORMANT PERIOD

The time when a plant has naturally stopped growing due to low temperatures and short day length.

DOUBLE

A flower with many more than the normal number of petals. When the whole of the bloom appears to be composed of petals it is called ‘fully double’ – a ‘semi-double’ flower is the half-way point between a single bloom and a fully double one. 

DRAWN

Term applied to pale and lanky seedlings which have been sown too thickly or grown in shady conditions. 

DRILL

A straight and shallow furrow in which seeds are sown. 

E

ENTIRE LEAF

An undivided and unserrated leaf.

EVERGREEN

A plant which retains its leaves in a living state during the winter.

EVERLASTING

Flowers with papery petals which retain some or all of their colour when dried for winter decoration.

EYE

Two meanings – a dormant growth bud or the centre of a single or semi-double bloom where the colour of this area is distinctly different from the rest of the flower.

F

FAMILY

A group of related genera.

FEATHERED

A petal on which there are feather-like markings on a ground colour which is distinctly different.

FERTILIZATION

The application of pollen to the stigma to induce the production of seed.

FIBROUS-ROOTED

A root system which contains many thin roots rather than a single tap root. 

FILAMENT

The supporting column of the anther. It is the lower part of the stamen.

FIMBRIATE

Frillly-edged

FLORE PLENO

Term applied to double flowers

FLORET

The individual flowers of a compound flower or dense flower-head

FLOWER

The reproductive organ of the plant.

FOLIAR FEED

A fertilizer capable of being sprayed on and absorbed by the leaves. 

FORCING

The inducement of flowering before its natural time. 

FRIABLE

Term applied to crumbly soil.

FROST POCKET

An area where cold air trapped during winter and in which half hardy plants are in much greater danger.

FRUIT

The seed together with the structure which bears or contains it.

FUNGUS

A primitive form of plant life which is the most common cause of infectious disease – e.g mildews and rusts. Such diseases are controlled or prevented by means of fungicides.

G

GENUS (plural GENERA)

A group of closely-related plants containing one or more species.

GERMINATION

The emergence of the root and shoot from the seed.

GLABROUS

Smooth, hairless.

GLAUCOUS

Covered with a bloom.

GROUND COLOUR

The main or background colour of a petal.

GROUND COVER

An ornamental plant which requires little attention and is used to provide a low-growing and weed-proof carpet between other plants.

H

HALF HARDY

A plant which will only grow outdoors in Britain when the temperature is above freezing point. The term is not precise – some half hardy plants can be left outdoors in winter in mild regions of the country.

HARDENING OFF

The process of gradually acclimatising a plant raised under warm conditions to the environment it will have to withstand outdoors. 

HARDY

A plant which will withstand overwintering without protection.

HEELING-IN

The temporary planting of newly-acquired stock pending suitable weather conditions for permanent planting.

HERBACEOUS

A plant which does not form permanent woody stems.

HERMAPHRODITE

See bisexual

HIRSUTE

Covered with stiff or coarse hairs.

HONEYDEW

Sticky, sugary secretion deposited on the leaves and stems by such insects as aphids and whitefly.

HOSE-IN-HOSE

A flower which gives the appearance of one bloom inside the other – e.g Canterbury Bell.

HUMUS

Term popularly (but not correctly) applied to partly decomposed organic matter in the soil. Actually humus is the jelly like end-product which coats the soil particles. 

HYBRID

Plants with parents which are genetically distinct. The parent plants may be different species, cultivars, varieties or occasionally genera.

I

IMBRICATE

Closely overlapping.

INFLORESCENCE

The part of the plant bearing the flowers – the flower-head.

INORGANIC

A chemical or fertilizer which is not obtained from a source which is or has been alive.

INSECTICIDE

A chemical used to control insects and other small pests.

INVOLUCRE

A ring of bracts surrounding a flower or cluster of flowers.

J

JOINT

See node.

K

KEEL

Boat-shaped structure formed by the two lower petals of many members of the Leguminosae.

L

LANCEOLATE

Spear-shaped.

LANKY

Spindly growth – a stem with a gaunt and sparse appearance.

LARVA

Immature stage of some insects, popularly known as a caterpillar, maggot or grub.

LATERAL SHOOT

A shoot which arises from the side of a main stem.

LEACHING

The loss of soluble chemicals from the soil due to the downward movement of water.

LEAFLET

One of the parts of a compound leaf.

LEAF MOULD

Peat-like material composed of partially-rotted leaves.

LEGUMINOSAE

The Pea Family. Many have papilionaceous (butterfly-like) flowers – e.g Sweet Pea.

LIGHT

Movable part of a cold frame.

LINEAR

Very narrow with parallel sides.

LOAM

Friable soil which is not obviously clayey nor sandy.

LOBE

Rounded segment which protrudes from the rest of the leaf, petal or other plant organ.

M

MONOCARPIC

A plant which dies after flowering and seeding.

MONOECIOUS

A plant which bears both male and female flowers.

MULCH

A layer of bulky organic matter placed around the stems

MUTATION

A sudden change in the genetic make-up of a plant, leading to a new feature which can be inherited.

N

NECTAR

Sweet substance secreted by some flowers to attract insects. 

NEUTRAL SOIL

A soil which is neither acid nor alkaline.

NODE

The point on the stem at which a leaf or bud arises.

NODULE

Swelling on the root of a member of the Leguminosae.

O

OBLONG

Longer than broad, with parallel sides.

OBOVATE

Egg-shaped, with broadest end at the top.

OFFSET

Young plant which arises naturally on the parent plant and is easily separated – e.g bulblet and cormlet.

OPPOSITE

Leaves or buds which are borne in pairs along the stem. 

ORGANIC

A chemical or fertilizer which is obtained from a source which is or has been alive.

OVAL

Egg-shaped, with broadest part in the middle. Compare obovate and ovate.

OVARY

The part of the female organ of the flower which contains the ovules.

OVATE

Egg-shaped, with broadest end at the base.

OVULE

The part of the female organ of the flower which turns into a seed after fertilisation.

P

PALMATE

Five or more lobes arising from one point – hand-like 

PANICLE

An inflorescence made up of a number of racemes.

PEAT

Plant matter in an arrested state of decay obtained from bogs or heathland.

PEDICEL

The stalk of an individual flower.

PEDUNCLE

The stalk of an inflorescence.

PELTATE LEAF

A leaf in which the stalk is attached to the undersurface and not to an edge – e.g. Nasturtium.

PERENNIAL
….

PERIANTH

The outer organs of a flower – the petals plus the sepals.

PETAL

One of the divisions of the corolla – generally the showy part of the flower.

PETALOID

Term applied to organs which assume the form of petals – e.g stamens in double flowers.

PETIOLE

The leaf stalk

pH

A measure of acidity and alkalinity. Below pH 6.5 is acid, above pH 7.3 is alkaline.

PICOTEE

Term applied to a narrow band of colour on a pale ground at the edge of a petal.

PINCHING OUT

The removal between the finger and thumb of the growing tip of the stem to induce

bushiness or to hasten maturity.

PINNATE LEAF

A leaf with a series of leaflets borne on either side of a central stalk.

PIPING

A cutting obtained by pulling off the tip of a non-flowering shoot – e.g Pinks and Carnations.

PISTIL

The female organ of a flower, consisting of the stigma, style and ovary.

PLUNGE

Term applied to the insertion of a potted plant up to its rim in a bed of peat, sand or ashes.

POLLEN

The yellow dust produced by the anthers. It is the male element which fertilizes the ovule.

POLLINATION

The application of pollen to the stigma of the flower.

PRICKING-OUT

The first planting out of a seeding or rooted cutting into another container or nursery bed.

PROPAGATION

The multiplication of plants.

PROSTRATE

Growing flat on the soil surface : procumbent.

PUBESCENT

Covered with short, downy hairs.

R

RACEME

An unbranched inflorescence which bears flowers on stalks. 

RADICAL

Term applied to a leaf which arises at soil level.

RENIFORM

Kidney-shaped.

RETICULATE

Marked with a branched network of veins or fibres.

REVERSION

A sport which has gone back to the colour or growth habit of its parent.

RHIZOME

A horizontally-creeping underground stem which produces shoots and roots.

ROSETTE

Term applied to a whorl of leaves arising at the base of a plant.

RUGOSE

Rough and wrinkled.

RUNNER

A stem which grows along the soil surface, rooting at intervals.

S

SAGITTATE

Arrow-shaped.

SCAPE

A leafless flowering stem.

SCREE

Bed of gravel, peat and soil for growing alpines.

SEED

The reproductive unit of a flowering plant.

SEED LEAF

See cotyledon

SELF-COLOURED

Term applied to a flower of a single uniform colour.

SEPAL

One of the divisions of the calyx. 

SERRATE

Saw-edged

SESSILE

Stalkless.

SIMPLE LEAF

A leaf which is not compound.

SINGLE

A flower with no more than the normal number of petals.

SPADIX

A fleshy spike in which small flowers are embedded.

SPATHE

A bract surrounding an inflorescence.

SPATHULATE

Spoon-shaped.

SPECIES

Plants which are genetically similar and which breed true to type from seed.

SPIKE

An unbranched inflorescence which bears stalkless flowers.

SPIT

The depth of the spade blade – about 10 in.

SPORT

A plant which shows a marked and inheritable change from its parent; a mutation.

SPUR

A tube like projection from a flower.

STAMEN

The male organ of a flower, consisting of the anther and filament.

STANDARD

Two meanings – either the large upper petal of Sweet Pea-like flowers or a plant with a tall bare stem and a terminal head of leaves and flowers.

STELLATE

Star-shaped

STIGMA

The part of the female organ of the flower which catches the pollen.

STIPULE

A small outgrowth at the base of the leaf stalk.

STOLON

A runner-like stem which forms roots and produces a new shoot at its tip (not at intervals along its length).

STOOL

The crown of a border perennial used for propagation.

STOPPING

See pinching-out.

STRAIN

A selection of a variety, cultivar of species which is raised from seed.

STRIKE

The successful outcome of taking cuttings – cuttings ‘strike’ whereas grafts ‘take’.

STYLE

The part of the female organ of the flower which connects the stigma to the ovary.

SUBSOIL

Soil below the fertile top layer.

SUCCULENT

A plant with fleshy leaves and/or stems adapted to growing under dry conditions.

SYNONYM

An alternative plant name.

SYSTEMIC

A pesticide which goes inside the plant and travels in the sap stream.

T

TENDRIL

A modified stem or leaf which can wind around a support. 

TERMINAL

Term applied to organs borne at the tip of a stem.

THROAT

The tube formed by the corolla of some flowers.

TILTH

The crumbly structure of soil at the surface.

TOMENTOSE

Densely covered with fine hairs.

TRANSPIRATION

The loss of water from the surface of the leaves and stems.

TRANSPLANTING

The movement of a plant from one site to another.

TRUSS

A flower-head or tightly packed inflorescence.

TUBER

…..

TUNIC

A dry and often papery covering of corms and some bulbs.

U

UMBEL

An inflorescence in which all the flower stalks are of similar length and arise from the same point.

UNISEXUAL

A flower of one sex only – see monoecious and dioecious.

V

VARIEGATED

Leaves which are spotted, blotched or edged with a colour which is different to the basic one.

VARIETY

Strictly speaking, a naturally occurring variation of a species – see cultivar.

VEGETATIVE REPRODUCTION

Division , cuttings, grafting and layering as distinct from sexual reproduction by seeds.

VIRUS

An organism which is too small to be seen through a microscope and which is capable of causing malformation or discoloration of a plant.

W

WEED

A plant growing in the wrong place. 

WHORL

Leaves, petals or branches arranged in a ring.