Raceme
An unbranched inflorescence bearing flowers on stalks.

Radical
Term applied to a leaf which arises at soil level.

Ramblers
Roses which produce long branches which can be trained to grow over a wall or screen.

Recurrent flowering
Several crops of flowers in one season.

Reniform
Kidney shaped.

Resistant
A plant that can overcome the effects of pests and diseases and severe weather conditions. Can also describe a pest which has become immune to particular fungicides and insecticides.

Reticulate
Marked with a network of veins or fibres.

Reversion
A mutation that has returned to the growth pattern of the parent.

Rhizome
A creeping underground stem which produces roots and shoots.

Rhizomorph
Fungal threads growing and spreading in a root-like mass.

Root ball
The soil ball formed around the root of a plant.

Rootstock
A plant onto which another is grafted.

Rosette
A whorl of leaves arising at the base of a plant.

Rugose
Rough and wrinkled.

Runner
A stem growing along the surface of the soil.

S

Sagittate
Arrow-shaped.

Scape
A leafless flowering stem.

Scarifying
The vigorous raking of the lawn to remove compacted matter.

Scion
A shoot grafted onto the rootstock of a different plant.

Seed
The result of plant reproduction.

Seed coat
Protective coating around an embryo.

Seed dressing
A powdered form of fungicide or insecticide used to give a light coating to the seed to protect it from pests and diseases.

Seed leaf
See cotyledon.

Self-coloured
The term applied to a flower with a single colour.

Self-sterile
A plant which produces pollen which cannot fertilize its own female organs.

Sepal
Part of the calyx.

Serrate
Saw edged.

Sessile
Stalkless.

Sets
Parts of bulbs used for propagating.

Shrub
A perennial plant with woody stems.

Simple leaf
A leaf which is not compound.

Single
A flower with the normal amount of petals.

Spadix
Fleshy spike with embedded flowers.

Spit
The depth of a spade blade.

Sport
A which has mutated from its parent.

Spot-treat
To treat a small defined area against disease.

Spreader
A chemical such as detergent is used in a spray to assist with even distribution.

Spur
A tube-like projection from a bloom.

Stamen
The male organ consisting of the anther and the filament.

Standard
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 which catches the pollen.

Stipule
Outgrowth at the base of the stalk.

Stolon
A prostrate stem which roots from its tips.

Stopping
See pinching out.

Strain
A selection of a species, variety or cultivar which has been raised from seed.

Strike
Cuttings 'strike' when they take root.

Style
The connecting part in the female reproductive organ between the stigma and the ovary.

Subsoil
The soil immediately below the fertile topsoil.

Succulent
A fleshy leaved plant ideally suited for dry conditions.

Synonym
An alternative plant name.

Systemic
A pesticide which is absorbed into the sap and carried through the plant.