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Achene A fruit with one seed, the fruit does not break open to expose or shed the seed.
Acidic(of soils) with a pH value of < 6.5
AdmixtureWeed seeds mixed in with the harvested grain
Alkaline(of soils) with a pH value of >7
AllelopathicThe inhibition of growth of one plant species by another due to the release of chemical substances.
Alternate(of leaves) growing up a stem first on one side and then the other, rather than immediately opposite each other
Alternately(of leaves) growing up a stem first on one side and then the other, rather than opposite to each other
AnnualA plant in which the whole life cycle from germination to seed dispersal occurs in one year
AntherThe part of the stamen that bears the pollen
ApexThe top part of a cotyledon, leaf or fruit.. The section furthest away from the stem.
Arrow-shaped leaf A basically diamond to triangular shaped leaf with lobes either side at the base.
AuricleIn grasses, a hook-like projection that wraps around the stem, at the end of the leaf sheath where the leaf blade meets the sheath
AwnIn some grass species, a bristle-like projection at the back or tip of a glume or lemma
AxilThe place where a leaf stalk or leaf blade meets the stem
AxisThe main stem of a plant, flowerhead or spikelet
BarbedWith sharp projections
Basal rosetteAcluster of leaves growing around the same stem node, usually near the ground
BeakA long thin extension of the tip of a pod
BiennialA plant which lives for two years, usually germinating in the first year and then flowering and producing seed in the second year, before dying
BiodiversityThe range of species found in a specific area
BiotypeA group of individuals within a species that are genetically distinct
Bipinnate(of leaves) having both leaves and leaflets divided to the central vein
BladeThe part of a leaf above the sheath
BolterA plant that flowers earlier than others around it
BractAmodified leaf that is found in a flower or flowerhead
Bracteole A little bract found for example around the smaller groups of flowers of fool’s parsley
BranchLateral growth from the main stem.
BreakA period between two similar crops when a different crop or no crop is grown
Break cropA crop grown between two related crops, e.g. oilseed rape grown between two cereal crops
BristleA stiff hair, or very fine straight awn
Broad-leavedFor this encyclopaedia - not a grass
BulbousSwollen at the base of the stem, resembling a bulb
CalyxThe outermost group of flower parts, composed of sepals which may resemble small leaves
Calyx-tube Where the sepals are fused at the base they form a calyx tube (for example in nettles).
CanopyThe parts of a plant, especially the leaves, that receive light from the sun and shade the ground beneath
CapsuleA fruit that dries and releases its seeds by splitting apart (as in mouse-ear) or by opening up small holes (as in poppy).
CellA section of a fruit, containing the seed
CiliaLong, thin projections
Clasp(of a usually stalkless leaf) to wrap around a stem
Clonal colony or clonal patchA group of plants that are genetically identical and different from others growing around them
Coleoptile (monocotyledons) The sheath covering the cotyledon
Compacted(of soil) compressed by the passage of vehicles
Compact-flowerhead(of flowerheads) having the individual flowers tightly packed together
Compact-plant(of plants) having a neat growth habit
CompetitivenessThe ability of a plant to grow successfully in relation to other plants around it
CompositeA plant that has flat flowers composed of florets arranged around a central structure, for example a daisy, dandelion or sunflower.
Compound(of leaves) divided into completely separate leaflets to the central vein or centre of the stem
CorollaThe group of petals forming a flower
Corolla tubeA group of petals fused together for the whole or part of their length
Cotyledona green structure resembling a leaf that appears as a seed germinates, before the true leaves appear
Cross-fertileFertilised by receiving pollen from another plant.
CulmStem of grasses.
DicotyledonA plant whose seed produces a pair of seed leaves as it germinates.
Disc floreta small tubular flower of which many are packed together in the flowerheads of plants such as thistle or in the centre of flowerheads such as those of daisy
DistributionThe geographical area throughout which a plant usually grows
DormancyThe period during which a seed or bud is not actively developing
DownyCovered with small soft hairs
EarThe flowerhead of a grass, especially wheat or barley
EllipticalShaped like a flattened circle
EmergenceThe germination of a seed, when the cotyledons appears above the ground
Entire(of leaves) not toothed or lobed
ExploitTo spread into or colonise an area
ExtendTo grow longer
Female flower partA single female flower part is called a pistil and consists of the ovary, which will become the fruit, containing ovules, which will become the seeds. On top of the ovary is the style which connects the stigma, the surface on which where pollen is deposited
FilamentStalk of anther.
FloretA small flower that forms part of a flowerhead
FlowerheadA group of small flowers on a single main stem
Folded(of leaves) folded lengthwise about the central vein, with the uppermost leaf blade folded in
Folded leavesLeaves folded lengthwise about the midrib. The upper most leaf blade folded in.
Fop' and 'dim' herbicidesHerbicides containing the chemicals diclofop and clethodim
FruitThe part of a mature flower that carries or encloses the seeds
GlabrousWithout hairs.
GlandA group of cells that secretes a sticky substance
GlandularHaving cells that secrete a sticky substance
GlaucousBluish-green in colour.
GlumeIn grasses, the outer empty bract of a floret, usually found in pairs
GraminicideA herbicide used for killing grass species
GroundkeeperA plant that grows from a storage organ such as a potato tuber or a sugar beet accidently left in the ground after harvest
HabitThe characteristic way of growing of a specific type of plant
HabitatThe type of environment in which a specific plant grows
HBN herbicidesHerbicides containing the chemical hydroxybenzonitrile
Hemi-parasite A plant that receives part of it’s food from the host on or with which it grows, while making some itself. As in red bartsia
Hemi-parasiteA plant that produces its own food by photosynthesis, but is able to extract water and minerals from the roots of the plants on which it grows, for example red bartsia
HerbA plant that does not produce a woody stem
HerbaceousNon-woody. Green and of soft texture.
HerbicideA chemical used to kill plants, especially to control weeds
HypocotylThe stem supporting a cotyledon or pair of cotyledons
InfestationThe uncontrolled spread of weeds in an area
InflorescenceThe flowering head at the top of the stem. Also called a panicle, raceme or spike in grasses.
Keel - leaf bladesA sharp fold or ridge at the back of a leaf sheath, blade, glume or lemma
Keel-seedThe sharp long edge of a seed with a triangular cross section
Kidney-shaped (Leaf or cotyledon) wider than long with a pronounced notch at the tip
Kidney-shaped(of a leaf or cotyledon) wider than long with a pronounced notch at the tip
LaminaThe leaf blade.
Lance shaped (Leaf or cotyledon) long and narrow tapering to a pointed tip
LanceolateLance-shaped. (Wider in lowest third and narrower at tip)
Lance-shaped(of a leaf or cotyledon) long and narrow, tapering to a pointed tip
LateralGrowing at the side, or situated at the side
Lateral lobes(of leaves) a division at the side
Latex A milky substance, usually seen when stems are broken.
Leach(of nutrients, chemicals etc.) To be washed out of the soil by rain or by irrigation
LeafletAn individual part of a leaf that is divided
LemmaIn grass flowers, the lower of the two parts of a floret
LeyAn area of grass sown as part of a system of crop rotation
LiguleAn extension of the leaf sheath, where it joins the leaf-blade
Lip The projections of the corolla of tubular or pea like flowers (as in red dead-nettle).
LipA projection on the lower part of a tubular flower such as pea or red dead-nettle
LobeA rounded division of a structure, e.g. A section of a divided leaf that is not cut as far as the middle, or part of a fruit
MealyAppearing to be spotted with or covered in white powder
MembranousThin, transparent and pliable
Micro-speciesIn some species such as dandelion, a group of plants that differ in their characteristics from other groups and reproduce asexually
MidribThe central vein of a leaf
MonocotyledonsA plant whose seed produces only one seed leaf as it germinates
Neutral(of soils) neither acidic nor alkaline, with a ph value of 7
NodeA slight swelling on a stem or axis from which a leaf or bract grows
NutletA small hard fruit
OblongUsed to describe a flowerhead, leaf or cotyledon that is longer than it is wide with parallel sides
Ochrea The membranous sheath that may surround the stem and leaf stalk as in redshank
OpenUsed to describe a plant or a flowerhead in which the individual branches or flowers are not tightly packed together
Opposite(of leaves) growing directly opposite each other on each side of a stem
PaleaThe upper bract of a grass floret
PanicleA loosely branched flowerhead
PappusA parachute of hairs at the top of the fruit of some plants such as dandelion and thistle
PerennialA plant that lives for more than two years, flowering each year
Perianth The group of calyx and corolla (sepals and petals).
PersistentRemaining or growing for several years
PetalThe innermost leaf-like, usually coloured parts ofa flower surrounding male and female parts
PetioleA leaf stalk
Phyllocronthe interval in thermal time from the emergence of one leaf tip on a shoot to emergence of the next
Pinnate(of leaves) divided to the central vein
PollinationThe process of transfering pollen from anther to stigma in a flower
Pore(in a seed head) a small hole or opening
Post-emergenceThe period after the cotyledons have appeared
PredationThe eating of seeds that have fallen to the ground by small mammals, birds, etc.
Procumbent Used when a plant lies loosely along the ground.
ProstrateGrowing flat along the ground
RacemeUnbranched flower-head, with the spikelets stalked directly on the axis.
RayA branch of the smallest flower groups in umbelliferous flowers
Ray floretsOne of the flowers making up the outer ring flowers of daisy-like flowerheads, with one long strap-shaped petal
ReceptacleThe swollen top of a flower stalk which supports the individual flower parts ofa compound flower
ReflexedPointing downwards or backwards
RegenerateTo regrow
RhizomeAn underground stem that is covered with scale-like leaves and can root at the nodes
RogueingThe removal of plants that are different from the required standard of the rest of the crop
Rolled leavesLeaf blade rolled within the leaf sheath.
RosetteA circular arrangement of leaves, all at one height, usually at the base of the plant on the ground
RotationA system of cultivation in which crops that have different nutrient requirements or are affected by different diseases are either grown one after the other or are interspersed with periods when no crop is grown
Row cropA crop that is planted in separated rows, for example onion, lettuce or maize
RunnerA stem that grows along the ground and forms a new plant at the tip
Seed longevityThe length of time for which seed remains able to germinate
Seed rainThe quantity of seed shed from a plant
Seed setThe production of seeds
SeedbankThe quantity of seed remaining in the soil that is able to germinate
Self-fertile(of a plant) able to be fertilised with its own pollen.
SepalThe outer, usually green, leaves surrounding a flower
Set seedTo produce seeds
SheathThe lower part of a leaf surrounding the leaf stem
Shed leavesTo lose leaves
Shed seedTo release seed
Simple(of stems) unbranched (of leaves) not toothed or lobed
Solitary(of a grass plant) having a single stem, rather than a group of stems
SpeciesA group of plants that can interbreed and have fertile offspring
Species A group of plants that are so similar they can interbreed and have fertile offspring
SpikeAn unbranched stalk of individual flowers, or groups of flowers (spikelets)
SpikeletIn grasses, a group of flowers, generally made up of two dry bracts (glumes) and one or more flowers
SpurA projection from the back of a petal, as in field pansy
Stale seedbedThe technique of allowing weed seeds to germinate before cultivation, or before drilling or spraying with herbicide
StamenA single male part of a flower, consisting of an anther containing pollen and its stalk (filament)
StigmaThe sticky surface at the tip of the style which receives pollen
Stipule A little scale, which may form at the base of a leaf, or a leaf stalk. In vetches as peas the cotyledons are hidden and the first projection on the stem is a stipule.
StipuleA small scale, which may form at the base of a leaf or a leaf stalk
StolonA stem that grows along the ground and produces roots and shoots at the nodes
Stout(of plants) strong or robust
Strap shaped Leaf or petal which has parallel sides but is very much longer than wide
Strap-shapedUsed to describe a leaf or petal that has parallel sides but is very much longer than it is wide
Stubble cultivationsShallow cultivations after harvest to create favourable conditions for the germination of the seeds of weeds and crop volunteers which can then be removed before or at planting
StyleThe stalk which attaches the pollen receptor to the ovary of the flower
Sub-speciesA division of a species, with distinctive characteristics
SwardAn area of grassland
TaprootA thick main root growing downwards into the soil, with much smaller roots branching off it
TendrilA thin clasping structure, developed from a stem, leaf or leaf stalk, that allows a plant to climb
TepalA fused petal and sepal, as seen in the flowers of goosefoots or redshanks
Thermal timeeach day the mean temperature (average of maximum and minimum temperature) is calculated. Thermal time is the sum of these means for each day (above 0°C) of the period being observed . The measurement is expressed as day degrees (°C days)
TillerA stem of a cereal or other grass plant,To produce multiple stems
TilleringThe stage at which a cereal or other grass plant produces mutliple stems
Toothed(of a leaf) having indentations along the edges
Trifoliate A leaf with three leaflets as in clover
True leavesThe first leaves that are formed after the cotyledon leaves have appeared from the seed
TuberA swollen part of a root or underground stem, which is used to store food for a plant and from which new plants may grow
TuftA group of several stems of a grass plant, which may be closely or loosely clumped together
TussockA dense raised clump of grass
Umbel A group of flowers arranged in a flat topped cluster with al the major flower stalks joining at a central point like an umbrella as in wild carrot. The smallest individual groups are called rays.
UmbelliferA plant with a flat-topped flowerhead (umbel) in which all the main flower stalks join at a central point, like the spokes of an umbrella
Unwinged(of a stem) having no outgrowth along its length
VegetativeUsed to describe reproduction from plant parts such as tubers or rhizomes
Vein(of a leaf or leaflet) having thickened and prominent vessels that transport food and water
VigorousGrowing strongly
VigourThe rate at which seeds germinate and seedlings grow
VolunteerA plant that has not been deliberately sown or planted
WhorlA set of three or more leaves growing from the same stem node and arranged in a circle
WingAn outgrowth on a stem or seed case