Foragers Glossary. A-Z guide to the language of plants.

Welcome to the foragers glossary, an A-Z foraging guide to the language of plants!

Learn the foragers language of plants with this A-Z foraging guide

This A-Z foraging guide is your foraging glossary of terms, intended as a reference guide for your hard drive. With easy access to this A-Z foraging guide, you can understand more of the words, terms, concepts and phrases that you are  no doubt encountering in books and online, while you go about increasing your foraging skills

This includes plants, fungi, algae (seaweed), and the whole gamut of available sea shore food.

As you deepen and broaden your learning about foraging, you will develop a new vocabulary; formed from botany and plant science, mycology, ecology, marine-biology, zoology and hopefully, gastronomy! This A-Z foraging guide can be on hand to assist beginners with grasping with a new language

Learning the language of plants (and other scientific languages) can be dauting, but just like learning spoken languages, they open up opportunities for personal growth. This A-Z foraging guide should enable the reader to understand plants more and therefore become a better forager.

So here are some of the common terms used in the plant realm.

A-Z foraging guide to the language of plants.


Achene A little one seeded nutlet formed from a single carpel, shed in fruit without opening to release the seed.

Acid soil  One which has a pH of less than 7.0. Soils with pH 5.0 or less are recognised as being very acid.

Acuminate   Narrowing gradually to a point.

Acute   Sharply pointed.

Adpressed   Lying flat; closely pressed against a surface.

Adventitious (of roots) arising in an unusual position, e.g. along a stem, like on ivy.

Allelopathy  The release into the environment by an organism of a chemical substance that acts as a germination or growth inhibitor to another organism. Typical substances include alkaloids, phenolics and terpenoids.

Aggregate species A group of closely related micro-species, which for the purposes of identification are better treated as one species. For example, blackberries, dandelions and hawthorns are all aggregate species.

Alkaline soils  Ones which have pH above 7.0. Degrees of alkalinity are known. These types of soil can generally have a large proportion of calcium ions in them. Soil pH does not usually get measured much more than 10.0 because of nutrient availability issues.  Soils over 8.5 are recognised as strongly alkaline.

Angiosperm  One of two divisions of spermatophyte (seed plants), These are flowering plants that have seeds fully enclosed by a fruit. As opposed to the Gymnosperms which bare their seed naked in a cone. Of the two, Angiosperms are the more evolved.

Annual A plant completing its life cycle in one year. They germinate in autumn or spring, then flower, fruit and die by the following autumn.

Anther  The terminal portion of a stamen of a flowering plant; the pollen sacs containing pollen are borne on the anther.

Auricle A lobe or pair of lobes at the base of a leaf, clasping the stem.

Apical bud  The active bud at the growing tip of a shoot.

Axil  The upper angle between a leaf, or leaf stalk, and the stem from which it grows.

Axis  The main (or central) stem of a plant or inflorescence.

Axillary bud  The bud situated in the axil.

Basal  At the base or bottom. The basal shoot or root on a plant is the bottom one. The basal cut on a scion or cutting is made at the bottom.

Basal or base plate  The flattened or squat conical stem within a bulb.

Berry A fleshy fruit containing one or more seeds, which do not have a stony inner coat around each seed (see also drupe).

Biennial A plant living for two seasons, normally germinating in the first spring and that year forming only leaves; then flowering and fruiting in the second season, before dying.

Blanching  The exclusion of light from a stem so that its green colouring (Chlorophyll) disappears. Blanching causes rapid stem growth (Etiolation).

Boron (Bo) A micro-nutrient essential for fruit and seed formation.

Bracts 1) A leaf, usually much reduced or modified, which subtends a flower or inflorescence in its axis.

Bracts 2) In umbellifers, a term used for the whorl of small leaves or bracts at the base of a main umbel

Bracteole 1) A tiny leaf on a flower-stalk without any flower in its axil.

Bracteole 2) In umbellifers, used for the whorls of small leaves or bracts at the bases of the secondary or partial umbels

Bud-break  The end of the dormant season, as perceived by a plant, when stems are induced to grow. It occurs when temperatures consistently rise above 5 degrees celcius/41F.

Bulbs  An underground storage organ, consisting of fleshy scale leaves, containing next year’s plant.

Bulbil   A small bulb

Calyx The whorl of sepals in a flower (used collectively)

Calyx tube The tube formed when the lower parts of the sepals are fused together.

Calcium (Ca) A macro-nutrient. Structural component of cell walls. Helps control cellular transpost of other nutrients.

Callus  The developing protective wound tissue produced by a plant on any damaged surface.

Cambium  The simple basic cells making up the actively growing tissue of a stem, root, or leaf from which the various ‘conducting’ tissues develop.

Capilliary action  A  process by which water rises above its normal level through a series of very small spaces, for example, through sand. The smaller the spaces the higher the water rises.

Chloride (Ch) A micro-nutrient required by plants in the leaves in specialised kidney shaped guard cells for the opening of stomata, thereby allowing for gaseous exchange. (See stomata)

Chlorophyll  The pigment in plant cells which gives their green colouring. Chorophyll are photosynthetic molecules which conduct the magic of converting light energy into chemical energy by absorbing light waves at 438-450nm and 660-670nm (blue, red, and far-red.) Very similar molecular shape to haemoglobin. Chlorophyll contains a central atom of magnesium whereas blood contains iron at its core.

Chloroplast  A semi-autonomous organelle within plant cells responsible for photosynthesis by means of its stacked membraneous discs containing chlorophyll pigment.

Chlorosis  A symptom of disease or disorder in plants, which involves a reduction in or loss of normal green colouration. Consequently, the plants are typically pale green or even yellow. Chlorosis is caused by conditions that prevent the formation of chlorophyll (e.g. lack of light or a deficiency in iron or magnesium). Don’t harvest chlorotic leaves.

Ciliate   Fringed with hairs, and usually referring to a leaf margin.

Cladode   A green leaf-like lateral organ or shoot; a branch resembling a leaf in form or function. As found on butchers broom.

Clone  A group of genetically identical plants produced vegetatively or asexually from a single parent.

Compound  Applied to flowers or leaves that have two or more parts.

Conical   Cone-shaped.

Copper (Cu) A micro-nutrient required for photosynthesis and other functions.

Cordate   A heart-shaped leaf, with the base rounded and prominently notched

Corymb A raceme in which the outer flower stalks are much longer than the inner ones, so that the flowers are all more or less at the same level in a flat topped cluster.

Cotyleden  A seed leaf borne on a plant embryo. For monocotyledons only one seed leaf is present whilst dicotyledons usually have two.

Crenate   With rounded teeth or lobes, scalloped.

Crenulate   Minutely create.

Culm   The flowering stem of a grass.

Cross-breeding  The breeding of two genetically unrelated individuals. In plants this can entail the transfer of pollen from one individual to the stigma of another genotype.

Crown  The part of a plant at or above ground level that normally produces stems. Herbaceous plants and occasionally woody shrubs that tend to grow densely are often referred to as having crowns.

Cutting  A  separated piece of root, stem or leaf that has been prepared solely to propagate a new plant.

Cyme An inflorescence in which the terminal flower opens first, followed in succession by lateral flowers growing from bract-axils lower down the inflorescence stalk. Cymes may be simple- with the flowers along the side of a single stem or double (as a dichasium)- which is a forked cyme with the oldest flower in the first fork (at the stem head) and the next oldest flowers terminating the opposite side branches; successive opposite pairs of branches arise below each terminal flower, and the process is repeated.

Day-neutral-plants A plant in which flower formation is not controlled by photoperiod or day length.

Deciduous A woody plant that drops its leaves each autumn and which produces new leaves from buds the next spring.

Decurrent Some leaves and mushroom gills can be decurrant, where they run down and are attached to the stem or stipe.

Dentate   Toothed, with acute teeth facing outward.

Denticulate   Minutely dentate.

Dessicate  To lose water, to dry out; to wilt.

Dichotomous branching  A repeated division into two parts.

Dicotyledons One of the two great sub-divisions of the flowering plants, with two first leaves on the germinating seedling. Dicotyledon leaves are usually net veined.

Diffusion  The movement of molecules from a region of higher to one of lower solute concentration as a result of their random thermal movement.

Differentiate  The process of changing from one or more simple plant cells, eg in the cambium, into a particular specialised organ or tissue, such as roots.

Digitate   With lobes like the fingers of a hand

Dioecious  Possessing male and female sexual organs or flowers on separate, unisexual, individual plants. As opposed to monoecious.

Disk-floret One of the tubular florets in a flower head in the daisy and teasel families.

Dormant  Asleep! A dormant seed or plant is one in a temporary resting state while it survives adverse climactic conditions.

Drupe A fleshy fruit resembling a berry, but with the seed inside enclosed in a hard stony case (like a plum or cherry).

Elliptic   Widest in the middle, tapering equally at both ends.

Endosperm.  A tissue within the seed, usually used as food storage reserves for the developing seedling.

Entire leaf A leaf without any teeth along its edge.

Ephemeral  A term given to species that with favourable conditions, complete their life cycle quickly, and a number of times over the course of a year. Many weeds are ephemeral species, as are many desert plants.

Epidermis  The outer most layer or layers on a plant, one cell thick.

Etiolation  The state of plants that have been grown in the dark: not green, little or no chlorophyll, extended internodes and rudimentary leaf growth. These features associated with etiolation, will ensure that in natural conditions that the shoot is carried toward the light as rapidly as possible.

Eye  A bud.

Fastigiate   With branches erect and more or less adpressed to the vertical.

Filament  The stalk of an anther, together with which they comprise a stamen. 

Floccose  Covered with tufts of soft, woolly hairs which rub off readily with age

Foliar  Of the leaf.

Fungicide  A substance that will kill fungi.

Flower  In angiosperms, the structure is for sexual reproduction, consisting of the androecium (male organs) and gynoecium (female organs) commonly surrounded by a corolla, (petals) and calyx (sepals). The male and female parts may be in the same flower or different flowers. In many plants the term flower is popularly applied to an inflorescence that in fact comprises many small flowers (florets) grouped together.

Fruit  Strictly, this is the ripened ovary of a plant and its contents. More loosely, the term is extended to the ripened ovary and seeds together with any structure with which they are combined e.g. the apple (a pome) in which the true fruit (core) is surrounded by flesh derived from the floral receptacle.

Gaseous exchange  The transfer of gasses between an organisms and its environment; it may occur in both photosynthesis and respiration.

Gene  The fundamental physical unit of heredity. It occupies a fixed chromosomal position, and when ‘transcribed’ has a specific effect on the ‘phenotype’. A gene comprises a segment of D.N.A coding for one function or several related functions. The D.N.A is usually situated in a thread-like chromosome together with protein within the cell nucleus.

Genus (pl genera) A grouping of species with important features of flower, fruit, and sometimes vegetative characters in common.

Genotype  The genetic constitution of an organism, as opposed to its physical appearance (phenotype).

Germination Technically, the point of appearance of the radicle (baby root) through the seed coat. In practice in the garden, we say a seed is germinated when its cotyledens (seed leaves) are fully opened. This is usually after a period of dormancy, and given suitable environmental conditions, most importantly warmth and moisture.

Glabrous Hairless.

Glaucous   Bluish-white. 

Globose   Spherical or globe-shaped.

Growth  The increase in size of a cell, organ or organism. This may occur by cell enlargement, or cell division.

Growth-form  The morphology of a plant, especially as it reflects physiological adaptation to the environment.

Gymnosperm  A seed plant in which the ovules are carried naked on the cone scales, in contrast to the angiosperms, in which they are enclosed by an ovary. They were the dominant vegetation in prehistoric times. Superseded by angiosperms through evolution.

Habitat   The living place of an organism or a community, characterised by its biotic or physical properties.

Herbicide  A chemical that will kill plants.

Hermaphrodite… A flower that has both male and female organs.

Hormone  A regulatory substance present throughout the plant’s life cycle, and available in different cells, active at low concentrations. The effects can be in distant cells or those all over the organism. It is conveyed via tissue fluids.

Humidity  The amount of water vapour in the atmosphere. Relative humidity is the amount of water in the atmosphere, relative to it being saturated, at a particular temperature (Warm air holds more water than cold air).

Humus  Decomposed organic matter of soils that are aerobic for part of a year. It is dark brown and amorphous, having lost all trace of the structure and composition of the vegetable and animal matter from which it was derived.

Hybrid  An individual plant produced by cross-pollinating two different parental genotypes (species or sub-species) Hybrids may be fertile or sterile.

Hybrid vigour (see heterosis)

Hypercotyl  The part of a seedling located between the shoot and root system. The area in which root tissues change to shoot tissues and vice-versa.

Imbibe  To drink in; absorb water.

Inferior ovary An ovary below the calyx and / or corolla (ie, the rest of the flower sits on top of it)

Inflorescence  A flowering structure comprising more than a single flower.

Insecticide  (see pesticide)

Internode  The stem portion between two nodes.

Involucre  A whorl of bracts below an inflorescence.

Iron (Fe) A micro-nutrient essential for photosynthesis.

Juvenile  A young immature plant before it reaches sexual maturity, and therefore, ability to flower.

Keel Of a flower, in the pea family, the two lower, partly-joined petals which form the shape like the keel of a boat.

Lateral  On the side. A lateral bud or root is on the side of a stem or root compared to the top or base.

Lanceolate  Sometimes broad, but tapering to a point at both ends, like the blade of a lance.

Leader shoot  The shoot that is dominating growth in a stem system, and is usually uppermost.

Long-day plant  A plant in which flowering is favoured and influenced by shorter periods of darkness, commonly less than 12 hours of darkness.

Macronutrient  An organic or inorganic element or compound which is needed in relatively large amounts by living organisms e.g. Nitrogen, Potassium.

Manganese (Mn) A micro-nutrient that functions with enzyme systems involved in the breakdown of carbohydrates and nitrogen metabolism.

Magnesium (Mg) A macro-nutrient vital for formation of chlorophyll. Involved in many enzyme reactions. Deficiency results in various symptoms, including chlorosis and the development of other pigments in leaves.

Mature  A plant which can bear flowers, and hence, reproduce sexually.

Meristem  A group of plant cells that are able to divide indefinately and whose main function is the production of new growth. They are found at the growing tip of roots and shoots (apical meristem), cambium (lateral meristem) and in grasses, also within the stem and leaf sheaths (intercalary meristem)

Micro-climate  The atmospheric characteristics prevailing in a small space, usually in the layer near the ground that is affected by the ground surface. Special influences include…the impact of vegetation cover on humidity (by evapotranspiration), temperature, and winds.

Micronutrient  An organic or inorganic element or compound that is required only in relatively small amounts by a living organism e.g. Molybdenum (Mo), Manganese (Mn), Zinc (Zn).

Micro-organism Literally, a microscopic organism. The term is usually taken to include to only those organisms studied in microbiology (ie bacteria, fungi, microscopic algae, protazoa and viruses). A wider context allows the inclusion of microscopic worms and other small critters.

Mineral soil  One where soil is composed predominantly of mineral matter and whose characteristics are determined more by the mineral than the organic content.

Molybdenum (Mo) A micro-nutrient believed to help with nitrogen metabolism.

Morphology  The form and structure of individual organisms, as distinct from their anatomy (which involves dissection).

Mulch  A loose surface soil horizon, either natural or man-made, composed of organic or mineral materials. It protects soil and plant roots from the impact of rain, temperature change or evaporation.

Mycorrhizae  A close relationship between a fungus (myco-) and plant roots (rhhizae-) from which both organisms appear to benefit; a mycorrhizal root takes up nutrients more efficiently than does an unaffected root. A wide array of plants can form mycorrhizae, some estimates suggest 9/10 plants do so in the wild.

Native  Applied to a species that occurs naturally in one area, and therefore one that has not been introduced by humans either accidentally or intentionally. Of plants found in a particular place, the term is applied to those species that occur naturally in the region and at the site.

Naturalised  Applied to a species that was originally imported from another country, but that now behaves like a native in that it maintains itself without the need for further human intervention and has invaded native populations.

Node  The place where a leaf joins the plant’s stem and subtends an axillary bud.

Nitrogen (N) A macro-nutrient needed by plants as an integral part of D.N.A and proteins and therefore required by each and every plant cell. N-deficient plants are chlorotic and etiolated, with the older parts becoming affected first.

Nitrogen fixation  The reduction of gaseous nitrogen and incorporation of molecular nitrogen into compounds. In nature this occurs after lightening storms, through photochemical fixation in the atmosphere and by the action of nitrogen fixing micro-organisms. Some of these are free living and others form symbiotic relationships with symbiotic bacteria, includiung Rhizobium and Bradyrhizobium species, which form the characteristic nodules on leguminous plants. The bacteria supply the legume with ammonia and receive carbohydrates from the legume. Certain non leguminous plants such as Alder and Bog Myrtle, commonly found on nutrient deficient soils, can form N-fixing relationships with Actinomycetes (a type of n-fixing bacteria)

Obligate A term applied to an organism that can only survive if particular environmental conditions are satisfied.

Obovate A leaf shape that is the reverse of egg-shaped, being wider at the tip than at the base. As found on alder.

Offset  A plantlet that develops laterally on a stem either above or below ground; the stem arises from a crown bud and usually carries no other buds.

Opposite  A leaf arrangement in which leaves arise in pairs, one pair at each node.

Organelle  Within a cell, a persistent structure that has a specialised function; e.g. mitochondria (respiration)  and chloroplasts (photosynthesis). In most cases, the organelle is seperated from the rest of the cell by selectively permeable membranes.

Organic matter  In particular the organic material found in soils, more generally, the organic component of any eco-system.

Organic soil  Soil with a high content of organic matter and water. The term tends to refer to peat. Has been defined as one with 20-30% organic matter, depending on the clay content.

Osmosis  The net movement of water or another solvent from a region of low solute concentration to a region of higher solute concentration, through a semi-permeable membrane.

Ovate A leaf shape that is egg shaped, wider at the base than at the tip.

Ovule  A structure in angiosperms and gymnosperms that, after fertilisation develops into a seed. In gymnosperms the ovules are unprotected, whereas in angiosperms they are protected by the megasporophyll (which forms the carpel). One or several ovules may be contained in the carpel and each is attached to the carpel wall by a stalk.

Ovum  An unfertilised egg cell.

pH A measure of the acidity or alkalinity of a solution. The pH scale ranges from 0-14, 7 being neutral. Values less than this are acidic, whereas above they are alkaline. The pH of body fluids must be around 7.4 for normal metabolic reactions to occur

Peat  An organic soil or deposit. Peat formation occurs when decomposition is slow due to anaerobic conditions associated with water-logging. Fen and bog peats differ widely.

Petiole  A leaf stalk.

Pericarp  The wall of a fruit.

Permanent wilting point (PWP)  The point at which a leaf will fail to regain turgidity should unfavourable conditions persist.

Pesticide  A chemical which kills insect pests.

Perennation  The survival of vegetative plant parts during the dormant season.

Perennial  A plant that normally lives for more than two seasons and after an initial period, produces flowers annually.

Petal  In a flower, one of the inner floral leaves, usually brightly covered and borne in a tight spiral, or whorled.

Phenotype  The observable manifestations of a specific genotype, i.e. those properties of an organism, produced by the genotype in conjunction with the environment, that are observable. Organisms with the same genotype may have different phenotypes because of the effects of the environment and of gene interaction.

Phloem  A tissue found in all vascular plants comprising many specialist cells, which transport solutes, synthesised in leaves, to all other parts of the plant. Located directly under the bark of a tree or other woody species.

Phosphorus (P) An element vital for plant growth, especially needed for the roots, DNA, and many metabolic functions. Deficiency leads to discolouration of leaves. Water-soluble, it leaches easily from the soil. Often unavailable as inorganic compound due to soil pH.

Photosynthesis  The reduction of atmospheric carbon dioxide to carbohydrates occuring within spcecialised plant cells which use light as an energy source and chlorophyll as a catalyst.

Photoperiod  The relative length of the periods of daylight and darkness associated with day and night.

Photoperiodism  The response of an organism to periodic, often rhythmic changes in either the intensity of light or, more usually, the relative length of day Tecnically its the period of darkness that the plant actually registers when initiating certain metabolic functions such as flowering.

Phyllosphere  The micro-environment on and below the surface of a leaf.

Phyllotaxis  The arrangement of leaves on the stem (opposite pairs, alternate, whorled etc).

Pigment  A colouration compound that produces colour in the tissues of living organisms.

Pinnate A leaf comprised of leaflets that sit opposite to each other on the stem.

Pinnately lobed A leaf that has opposite leaflet lobes

Pistil The collective name often given to the organs of the gynocaeium, including stigma, style, ovary.

Pith  A central stem tissue.

Plicate  Folded or wrinkled.

Plumule  The primitive shoot apex in a plant embryo.

Pollard  To behead a tree at a convenient height, usually about 2metres above ground level, in order to produce a crown of small poles, suitable for firewood, fencing etc. This allows the production of small material out of reach of deer and farm livestock.

Pollen  Collectively, the mass of pollen grains or micro-spores produced within the anthers of a flowering plant (angiosperm) or the male cones of a gymnosperm.

Pollination  The transfer of pollen grains from the anther (male reproductive organ) to the stigma (female reproductive organ) of a flowering plant. This process facilitates contact between male ‘gametes’ and the female ovum, leading to fertilisation, development of seed and eventually a new plant.

Polyploidy  The condition whereby an individual possesses one or more sets of ‘homologous’ chromosomes in excess of the normal 2 sets found in diploid (2n) organisms. Cultivated strawberry and yarrow are two common plants which are polyploids. The difference in numbers of chromosomes can result in totally different chemical profiles or chemotypes. It is caused by the replication within a nucleus of complete chromosome sets without subsequent nuclear division. Examples are triploidy (3n), tetraploidy(4n), hexaploidy (6n), and octaploidy (8n) – (where ‘n’ is one set of chromosomes).

Potassium (K) A macro-nutrient that is vital for healthy plant growth especially flowering and fruiting. Deficiency leads to reduced growth and to dark or blue green colouration in the leaves, which can also develop a purple-brown pigment.

Puddled or Poached soil  Soil in which the structure has been destroyed by the physical impact of rain drops.

Pulvinate  Cushion-shaped; swollen or convex.

Punctate  Applied to any structure that is marked by pores, or by very small point-like depressions.

Pyriform  Pear-shaped.

Raceme  An infloresence where the axil continues to grow extending upwards so that the youngest flower(s) is displayed at the apical tip.

Radicle  A rudimentary root in an embryo.

Regeneration  Initiation and growth of any missing parts on propagated material (for example, roots on a stem cutting) to make a complete plant.

Relative Humidity (See humidity)

Reniform A kidney-shaped leaf

Respiration, The liberation of energy by cells to help fuel growth and meet its current demands.

Rhizosphere The immediate soil root-zone occupied by and affected through the action of roots and their exudates, growth, exhange of nutrients and respiration. It is a region of high soil-organism and micro-organism activity.

Riparian   Pertaining to the bank of a river or shore of a lake.

Root  The lower part of the plant, traditionally anchored in soil, providing water and nutrients to the organism.

Root nodule The gall-like growths observable on the roots of certain plants, most identifiable on legumes. The nodules develop from sites of infection and are caused by the bacteria rhizodium and bradyrhizobium; two specialist bacteria which fix atmospheric nitrogen as their chief source of energy, and happily, symbiotically, co-exist with plants. Much of the bacterial nitrogen becomes available to other plants.

Rust  A plant disease caused by a fungus in the class of Urediniomycetes. The characteristic symptom is the development of spots, and powdery spores, which are usually rust covered, yellow or brown. Infected plants may also show distortions or ‘gall-like’ swellings.

Runner  An overground stem, sent generally from a crown of herbaceous plants with only a terminal bud. Strawberry plants and couch grass are two plants which have runners.

Sap The exudate from the wounded tissue of vascular plants. Ranging from rubber to mayple syrup.

Sapling A young tree, from seed or sucker, not yet of economic importance.

Sapwood The heart of the active xylem cells which are next to the dead cells. This is easily distinguished by the darker colour.

Scale leaf A leaf modified to form a scale on an underground stem.

Seed lot  A collection of seeds from a particular source of plant or plants.

Short-day-plant These plants form flowers only when the night length is more than 12 hours

Succulent  This condition seems to have developed as a response to a lack of water in the arid zones that this type of plant tends to populate. A succulent is capable of storing up relatively large quantities of water, as well as fixing carbon dioxide at night in contrast to the majority of other plants which assimilate carbon as they photosynthesise.

Sucker  A shoot growing either from a stem or a root, at or about the ground level.

Stomata Microscopic holes on the undersides of leaves enabling gaseous exchange. Each stomata is enclosed by two ‘guard’ cells. When these relax the holes allow CO2 to enter and oxygen and water to diffuse into the atmosphere.

Sulphur (S) A macro-nutrient. Required for producing protein. Improves root growth and helps formation of chlorophyll.

Tendril  A modified stem that is to be found twining, grasping and twisting its thread-like attachment. Peas, beans, passionflower and many other plants have tendrils. In the plant kingdom the responses from tendrils to touch are analogous to animals. Indeed, the sensitivity of plants to their environment is arguably superior to humans.

Terminal bud  The bud that terminates growth at the top of a stem, resting throughout the dormant season.

Transpiration  The process by which the plant moves water from the soil through its tissues and out of the tiny (stomata) holes in the leaf. Approximately 93% of all water a plant takes up through its roots will be transpired through the leaves.

Tuber  A swollen modified underground stem, adapted into a storage organ. Usually the axillary buds are next year’s new growth. It is these so called eye’s which will ‘chit’ pre-empting their desire to grow. As opposed to tuberous roots.

Tuberous roots  Found under perennial herbaceous crowns which act as storage organs for the dormant season. Can be found on annuals also.

Turgid  A cellular state, as opposed to flacid. Tort, rigid or full are words associated with turgidity. It is brought about by hydrostatic pressure.

Thorn A woody projecting structure with a sharp point derived from the stem, branch or leaf of the plant. It is connected to its vascular system. Can disappear in maturity, as on roses, and the holly leaves.

Tilth  The physical condition of soil that determines its suitability for cultivation.

Tissue  A group of similar cells working in a co-ordinated manner towards a common metabolic and / or structural function. In plants cells are normally bound together by cell walls. Fluids are also considered tissue.

Trichome  A single cellular outgrowth, e.g. a root hair, arising from an epidermal cell.

Union  The union where a rootstock and a scion join in graft to develop and grow as a whole.

Vagile Applied to a plant that is free to move about. Seeds, pollen grains and spores can travel miles on the wind.

Valvate  Applied to a flower where the petal or sepals meet at the edges but do not overlap.

Variegation  A phenomena whereby two or more distinct colours are revealed on a leaf; plant names commonly ending ‘variegata’ have this feature. Variegation may be inherited and also as a result of viral infections.

Vascular bundle  Longitudinal strands of xylem and phloem conducting tissue, essential for transport of water and solutes throughout the organism. It also helps structural support within a plant.

Vegetative  Applied to a structure or stage that is concerned with feeding and growth rather than with sexual reproduction. Vegetative reproduction is therefore asexual reproduction.

Vein  A vascular bundle or group of vascular bundles lying in close proximity in a leaf.

Venation  The arrangement of veins in a leaf.

Vernalisation  The process of subjecting seeds and plants to low temperatures in order to break dormancy and trick the plant’s flowering responses. A natural cyclic event for an organism in the UK experiencing the seasonal changes and associated change in day length.

Water-stress A variable condition where a plant is losing more water than it is taking on board. Can easily result in ethylene production by the plant which inhibits growth even more than simple water stress. 

Weed   A plant opportunistically taking advantage of suitable conditions having been distributed by human intervention. A plant out of place, competing for water, nutrients and light.

Whorl  A variable group of three or more flowers or bracts or any other ringed floral stem arrangement.

Wilting  When cells have insufficient water to maintain turgidity. May occur when the rate of transpiration exceeds that of water entering the root cells, in a soil containing ample water, causing the tissues to lose turgidity and droop downwards. This response is designed to get the leaf out of the sunlight. It can also occur when there is not adequate water in the soil. Mulching alleviates this. Although some plants such as the curcurbits will limp naturally in the sun.

Xylem   A tissue specifically designed to conduct the water and solutes entering the root. Consists of various cells and is distinguishable by the presence of vertical systems of dead cells which have thickened lignified cell.

Zinc (Zn) A micro-nutrient required for plant growth as a part of enzyme systems and essential for transformation of carbohydrates.