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Glossary of plant terms

Search our dictionary of 3,300 botanical and plant-related terms – the largest online.
Or browse the descriptions and definitions using the A-Z.

F1 hybrid

The first generation produced from crossing two distinct plants (usually when the parents are pure bred lines and the offspring is vigorous). The seed from F1 hybrids does not usually "come true to type"; ie have the same characteristics as the F1 hybrid.

F2 hybrid

These are plants grown from seeds produced as a result of self-fertilizing or cross-fertilizing F1 hybrids. F2 hybrids are less uniform than F1 hybrids.


A measure of temperature (F) where the freezing point of water is 32F (or 0C), and the boiling point is 212F (or 100C).

fairy ring

This is a ring of toadstools or other fruiting bodies, which often is associated with a patch of discoloured turf indicating the underlying fungal mycelium which has extracted nutrients from the soil. Folk-lore has it that fairies may dance in these fairy rings by moonlight.




Means "sickle shaped" in Latin.


Refers to land which has been ploughed and harrowed, but left without a crop in order to "rest" the soil and destroy the weeds. The land may also be left uncultivated for a period to allow the soil structure to improve and to reduce the risk of pests or diseases being passed onto new crops.


The outer set of petals which are usually broader than the inner, and often drooping, as in an iris.


An apparent fruit which is actually formed by tissues (such as bracts or receptacle) in addition to the real fruit.

false silver leaf

A disorder affecting cherry and plum trees where leaves on entire tree turns silvery; no die back.


A group of plants with many common characteristics; usually composed of many genera. Families are grouped together into a classification taxon called an order.


This may be used to describe a flower which has unusual colouration or is patterned, fringed or in some other way distinctive.


Refers to a disorder affecting carrots, parsnips, and beetroots where the roots are forked and distorted.

fan palm

This is a palm with palmate rather than pinnate leaves.

fan trained

This is a method of training trees and shrubs where the branches are spaced equally in a fan or crescent from a single trunk or stem. This is often done with fruit trees to enable them to be grown up against a wall or fence, so reducing the space taken up.


A powdery, whiteish deposit which is naturally occurring on some leaves and flowers.


Means "mealy" in Latin.


This is a condition where a number of organs or structures are fused together into a broad form; for example the stamens may be fused together in the flower. The fasciation may be caused through an infestation by a pathogen or by a physiological abnormality in the plant. Some affected plants may be cultivated for their curiosity and decoration.


Means "bound together" in Latin.


Clustered tightly in no apparent pattern. A "fasicle" may refer to a dense cluster of flowers or stems.

fastest growing plant

Some Bamboo species have been measured growing at 90 cms (about 3 feet) per day.


With branches erect and close together.


Means "fastigiate" in Latin.


This refers to a method of growing a young standard tree which has lateral shoots on the main stem, and where these shoots are pruned by half in the first winter. This allows these green shoots to contribute to nourishing the main stem. In the second winter the lateral shoots are removed to leave a clean trunk.


Cut into many fine segments.


A general term used for a plant fertilizer in solid or liquid form. An example would be a foliar feed which is applied as a liquid in spray form onto the surface of leaves to be absorbed.

felt gall mites

Dense coating of creamy-white (or purple) hairs develop on undersides of leaves. Felt galls are formed. They affect alder, beech, birch, crab apple, lime, maple and sycamore.

female flowers

Flowers with an ovary but without stamens.


Refers to leaves which have holes or transparent areas (windows).


This may be an active ingredient in some pesticides. It is an organophosphorus compound and is toxic to birds, fish and other animals; at least two weeks must elapse before the harvesting of edible crops.


The "true ferns" belong to the order Filicales, in the class Filcopsida, in the division Pterophyta. They are green plants with fronds which unroll as they grow from the centre. The plants do not produce flowers but reproduce in two stages using spores to produce a protothallus, which then give rise to the sporophyte.

ferrous sulphate

This chemical may be used in compounds to kill moss in lawns. The name iron sulphate may be used as an alternative.


Means "rust coloured" in Latin.


Rust coloured.


Referring to stamens producing good pollen, or fruit containing good seeds, or of stems with flowering organs. This term is also used to refer to soil with a good range of nutrients, able to grow healthy plants.


Means "many seeded" in Latin.


The fusion of the male and female gametes (haploid) so that a zygote (diploid) is formed. In flowering plants the male gamete is the pollen grain, and the female gamete is the ovum in the carpel of the flower, and after fertilization the embryo in the seed is formed.


Any of a large number of natural or synthetic materials which are spread onto or worked into the soil to increase its fertility. Examples are manure, humus, and other compounds which may include ratios of nitrogen, phosphorus and potassium (NPK; the 3 main nutrients or macronutrients).


Means "wild" in Latin.


Means "bright" in Latin.

fever flies

Irregular yellow patches appear on turf. The larvae live together in colonies in turf.


Refers to plant-based tissue which has cellulose and/or lignin as part of the cells which give strength and support to the plant. Plant fibre can form part of a healthy diet for humans.

fibrous root

A root system composed of many fine roots, and where there is no main axis (such as in a tap-root). The fine roots are mainly in the upper soil layers where they can take up nutrients and water.

field crop

Refers to a crop grown on a large scale.

fig canker

Cankers appear at bases of branches of fig plant. May appear near pruning cuts or wounds. Branches may killed.

figwort weevils

Beetles infest the shoot tips of plants destroying foliage and flowers. Affects figworts, phygelius, buddleja and verbascum.


The thread-like stalk of the stamen bearing the anthers. The filament holds the anther away from the flower to enable the free release of pollen.


A term describing an organism growing in a long strand-like form.


Refers to parts of a plant which might be finely divided, such as leaves or stems.


Thread-like or wire-like.


Means "threadlike" in Latin.


Fringed, usually referring to the edge of leaves or petals.


Means "fringed" in Latin.


This can be an important event in ecosystems. Regions prone to frequent bush fires such as in many parts of Australia have developed vegetation that copes with burning, such as eucalyptus trees (having protective barks) and plants with seeds which germinate after the heat of a fire has stimulated them. Fire absorbs oxygen from the air and produces carbon dioxide after the carbon in the organic material has been "oxidised". Ash from a fire may be a suitable fertilizer. However, fires set by humans can have horrendous consequences for the environment. For example, fires used recklessly to clear vegetation for palm oil crops in Indonesia and Malaysia during 1997 destroyed eco-systems estimated at half the size of the British Isles. The smoke turned into an evil smog and it has been calculated that the cost of poor health cost the economies about 5 billion dollars. In addition, such events are thought to exaggerate climatic variations which can lead to problems for other countries. However, fires set by humans can have horrendous consequences for the environment. For example, fires used recklessly to clear vegetation for palm oil crops in Indonesia and Malaysia during 1997 destroyed eco-systems estimated at half the size of the British Isles. The smoke turned into an evil smog and it has been calculated that the cost of poor health cost the economies about 5 billion dollars. In addition, such events are thought to exaggerate climatic variations which can lead to problems for other countries. Out of control bush fires during 1994 near Sydney in Australia were partly a result of preventing fires in an environment where naturally periodic fires cleared out dry undergrowth. For growers who want to use fires to clean up diseased or overgrown vegetation (e.g. burning back Pampass Grass), consideration needs to be given to choosing social hours and checking that wildlife such as hedgehogs are not trapped. There should be adult supervision and water should be available in case the fire gets out of control.


This is a disease caused by bacteria which can infect certain shrubs and trees in the Rosaceae family, including Sorbus, Malus and Pyrus. The flowers are affected first (starting at the nectaries and spread by pollinating insects) turning the flower black and making it wither, and then spreading down the stem to kill whole branches and then possibly the plant.

fire disease

This a disease which causes the leaves to change colour to red or brown, and which is usually caused by a fungal infection. It may occur in tulips and daffodils, can easily spread through the soil to other plants, and may kill the plants.

fish meal

This is dried and ground fish products which may be used as a plant fertilizer, and usually mixed with dried blood and bonemeal to supply a nitrogen and phosphate feed.


The asexual division of a unicellular organism into 2 similar organisms.


Means "fanlike" in Latin.


May refer to plant cells and tissues which have lost their turgidity and become soft through loss of water.


Means "feeble" in Latin.


Having flagella, which are movable hair-like structures. This can make an organism mobile in an aquatic or moist environment.

flag iris

A type of iris that has rhizomes and not bulbs.


The Australian flatworm is proving a danger to earthworms in Britain, probably having been imported by humans. They do not usually affect plants directly, but some species feed on earthworms and hence damage the general soil environment.


Means "yellowish" in Latin.

flea beetle

A pest on Brassicas causing feed marks, sometimes completely destroying plants.


Means "zig-zag" in Latin.


Zigzag or wavy.


A general name for various species of flying insects. Some of them are pests such as the carrot flies whose maggots tunnel into the roots of carrots, parsnips, parsley and celery. The onion fly is another pest for the grower. The common "house fly" (Musca domestica) is not so much of a pest to crops since it tends to lay its eggs in decaying organic matter and feeds on generally exposed organic matter.


Covered with soft hair or woolly.


This may refer to a cultivation technique where lime or humus is added to fine-particled clay soils to create larger particles and so improve the drainage and aeration of the soil.

flor ...

This is a prefix to a word which generally means flower or flower-like.


Usually refers to any plant life, or possibly just to flowering plants.

floral formula

This is a botanical notation that describes the organs in a flower, and which aids classification and identification.

flore pleno

A double flower with many more petals than normal, usually due to the conversion of stamens to petals.


A small flower, usually one of a dense cluster or inflorescence.


Refers to a type of plant producing many flowers, usually held in clusters. The name Floribunda is a group name for roses which produce a cluster of blooms at the end of each stem.


Means "free-flowering" in Latin.


The cultivation of flowering plants, usually for cut flowers.


Flower-bearing; usually indicating profuse flowering.


The reproductive organs and associated structures of a plant (chiefly of angiosperms). The flower is usually made up of petals, sepals, androecium (male parts) and gynaecium (female parts). There are often nectaries and scent glands. The structure of the flower is generally determined by the method used for pollination; insect pollinated flowers are usually coloured and showy to attract insects, whereas wind pollinated flowers are less conspicuous with exposed anthers and stigmas. There are a number of "flower forms" including single, semi-double, double, and fully double.

flowering plants

A general term for members of the Angiosperma division, which produce flowers as part of their reproductive mechanism.

flowers of sulphur

A yellow powder form of sulphur chemical which may be used as a fungicide (sulphur treatments) or possibly as a soil acidifier.

flower stalk

Botanically known as the pedicel.


Means "floating in water" in Latin.


This term may be used to describe the production of shoots, leaves or flowers at a particular time.


A crop which has been harvested for animal food.


Means "stinking" in Latin.


This is a propagation method where the cuttings are misted with very fine suspended drops of water so keeping up a high humidity without drenching the plant surface or the soil.


Leaf-like; of an organ not normally so.


General term for the leaves of a plant.

foliar feed

Usually a spray which contains nutrients that can be absorbed by the leaves or shoot. A foliar feed can be used as a way of supplying rapidly absorbed nitrogen for healthy leaf growth.


A dry, usually many-seeded fruit, formed from one carpel and which is dehiscent along one side. It can also refer to a gland which secretes substances onto the surface of the plant.


A term for any sort of fanciful ornamental structure or building.


A sulphur-based organic fungicide which may be an ingredient in combination with Dinocap of some wettable powder and spray preparations.

fomes pomaceous

Fungal fruiting growth develop on bark. The wood within may decay.

fomes root and but rot

A bracket fungus develops on trunk or butt of trees, (usually at ground level) causing rotting and deterioration of the wood/tree.

food chain

This refers to the order in which species are dependant on each other for food. Organisms which are photosynthetic (plants) are primary producers in the food chain with herbivorous animals feeding on them, and other animals feeding on these "secondary producers".


A measure of length (ft) equivalent to 12 inches or 30.5cm (centimetre).

foot rot

A disease affecting French beans, peas, and runner beans where the leaves go yellow; stem bases black and rotten.


Plants which are being grown for feeding to animals.

forage harvester

A machine that gathers grass or other plants (usually by rotating blades) and then throws the plant material into a trailer (perhaps to make silage), or possibly into rows on the ground to dry out for hay.


To artificially induce the early production of growth, flowers or fruits. Plants can be forced by the provision of shelter and warmth such as "forced chrysanthemums". Bulbs may be forced to give indoor flower displays in early spring. Vegetables such as rhubarb may be forced, protecting the shoots to provide tender stems.


The cultivation of trees for commercial purposes, such as timber production.


General term for a pronged implement for digging; may also refer to cultivation with a fork. Also refers to a more or less equal branching or division of a stem or tree trunk.


Carrots and parsnips roots are mis-shaped and distorted but are still edible.


A slight but distinctive variant of a species, often occurring sporadically. There is a botanical convention on nomenclature that forma or subspecies names are in Latin with lower case letters as they are of natural origin. Varieties or cultivars are printed with initial capital letters since they are human-made. (Often the cultivar name is placed in quotes but in this package the cultivar names are not placed in quotes since they are distinguished by having initial capital letters.) 'Form' may be abbreviated to f.


The botanical reference to a form which is a slight but distinctive variant of a species, often occurring sporadically.


Formalin is a name for a 40 percent solution of the chemical formaldehyde. It is used as a general sterilizing agent and preservative.

formal garden

Refers to a garden with a geometrical layout.


This is a name for a 40 percent solution of the chemical formaldehyde. It is used as a general sterilizing agent and preservative.


Means "beautiful" in Latin.


An organophosphorus systemic insecticide used to control a range of insect pests, but it is also toxic to bees, birds and other animals. At least one week must elapse before harvesting edible crops.

Forsythia gall

Hard, rough, irregular shaped galls develop along length of stems.


The "fossilised" or "fixed in stone" remains of an organism. This is a result of the original organism having died and the remains being covered or encased in some form of sediment, producing a mineralised and hardened structure over a great many years. The fossil may be uncovered later by erosion or digging by humans.


Foxes tend to dig up or trample on plants. Dog foxes use their faeces and urine to mark out their territories. Urine can scorch the foliage of plants (especially conifers) and has pungent smell.


Means "sweet scented" in Latin.

fragile soil

Refers to soils which can dry out and fall apart easily. Such soils may have a low clay content and possibly a low organic and humus content. Examples are the soils which were blown away from the "dust bowls" of the USA and Africa, when high winds removed (erosion) the topsoils. Much of the soil covering Australia is of an ancient origin and has a poor structure which means that it is prone to being blown or washed away. Good cultivation practises such as contouring and avoiding leaving fragile soils exposed without vegetative cover is important to conserve this valuable resource.


Means "brittle" in Latin.


Means "sweet scented" in Latin.


Means "very sweet scented" in Latin.


Refers to a box with a glazed cover used to protect plants from low temperatures usually. A frame may also be some sort of support for plants.


Not joined to other organs, e.g. as petals to stamens, or petals to each other.

French drain

A term for a trench filled with aggregate which allows water to drain away.


This term may be used to describe a soil with a good aerated structure, and which can be cultivated easily.


Means "cold" in Latin.


A small insect pest which sucks the sap of various plants and creates a frothy substance (cuckoo spit) which covers the larvae. Another name for a froghopper is spittle bug.


The leaf of a fern or a cycad.


Means "leafy" in Latin.


When the temperature falls below 0C (32F) water vapour in the air freezes onto surfaces. Many plants, especially succulent ones, are vulnerable to frost since the fleshy tissues contain a lot of water in the cells which rupture and die. If a plant is able to withstand frost it is referred to as hardy.

frost action

Refers to the freezing and thawing of water which breaks down soil or other structures by the alternate expansion and melting of water. Cultivated soil is often left over winter to enable frost action to break it down.

frost damage

A disorder which can affect plants such as strawberries where the centre of flowers turn black.

frost hardy

The plant can tolerate temperatures down to about -5C or 23F. Climatic zone of 9.

frost pocket

Refers to a low-lying area where the temperatures tend to fall below the usual temperatures for the region, and so there is more chance of frost. The frost tends to persist longer than elsewhere because the dish-like contours of the ground tends to collect freezing air and does not allow it to flow away to lower areas.

frost tender

The plant can be damaged by temperatures below 5C or 41F. Climatic zone of 11.


Refers to the process of producing fruit or spore-making bodies.


This is a form of sugar produced by most plants and can be found in organs such as the fruit.


The seed containing structure derived from the ovary (chiefly of angiosperms) which can include other parts such as food tissue. Examples are berries and apples.

fruit bud

Refers to a bud that will give rise to a flower then a fruit, as opposed to a wood bud that will develop into a shoot.

fruit cage

Refers to a net covering over a frame to protect fruit from birds and other pests.

fruit drop

A disorder affecting apples, pears, and plums where the developing fruits fall early; no sign of insect damage.

fruiting body

Refers to a spore-making fungal structure, which can appear from the ground or surface of a plant. Mushrooms and toadstools are examples of fruiting bodies.

fruit not forming

The disorder where the flower appears but no fruit follows; can affect a range of plants. Possibly a suitable pollinator is not present. Frost damage may produce the same symptoms.

fruit set

Refers to the time at which the fruit has begun to develop following successful pollination and fertilization.

fruit tree red spider mite

The foliage losses its glossy green appearance to appear dulled and mottled yellow caused by sap-feeding mites.


Means "becoming shrubby" in Latin.


Means "shrubby" in Latin.


Means "shrubby" in Latin.

Fuchsia rust

Yellow-orange fungal patches develop on lower leaf surface and fall early. May kill plants.


Means "shining" in Latin.

fully double flower form

A flower which is usually rounded in shape, with densely packed petals and with the stamens hidden.

fully hardy

The plant can tolerate temperatures down to about -15C or 5F. Climatic zone of 7.


Means "tawny" in Latin.


Refers to the disinfecting (killing insect pests, fungal spores, bacteria) of soil or plants by fumes from burning certain chemicals in greenhouses.


Means "smoky" in Latin.


Means "funereal" in Latin.


Plural of fungus.


A substance used to combat fungal diseases.


Organisms which lack chlorophyll and are usually saprophytic or parasitic, including yeasts, moulds, mildews and toadstools. The mycelium of most fungi consist of thread-like hyphae which spread through the soil, rotting wood etc and act to digest nutrients from organic matter.

fungus gnats

Several species of fungus gnats which occur in greenhouses and house plants more profusely. Grey brown flies run over the soil and feed on decaying organic matter.

fusariosis (premature dying of plants)

A fungal disease affecting potatoes and other plants. The Fusarium fungus may be in and on the seeds; the attacked plants die.


This is a fungal disease which causes certain plants to wilt and die. The disease is soil-borne and can be a problem when plants are grown in the same soil over successive years.

Fusarium wilt

Plants discolour and wilt. Dark discolouration at the base and a pale pink growth may be seen. May eventually die.

fusarium wilt (fusarium patch)

Fungal disease that affects lawns where the lower grass leaves and stem bases turn brown and rot. White or pink fungus strands are visible. The grass turns yellow in patches, then brown before dying off.


Means "dark coloured" in Latin.




Means "spindle shaped" in Latin.


Means "futile - useless" in Latin.

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