Gardening Definitions (R-T)

Radical
Usually used to describe the basal leaves of biennials or perennials. The leaves arise at the base of the plant or near to soil level.

Ray Floret
Small flower with long strap-shaped petals. Typical of the daisy family where a ring of ray florets surrounds the central boss of disc florets to form the flowerhead.

Remontant
Flowering at intervals throughout the growing season, as in repeat flowering roses.

Resting Period
The period when a plant is either dormant or making little or no extension growth.

Rhizome
A horizontal,creeping underground stem, which acts as a storage organ.

Rootstock
A propagation term for a plant upon which another is grafted. The term also applies to the crown and root system of herbaceous perennials and suckering shrubs.

Rosette
Ring of leaves that all arise at more or less the same point on the stem, often basal.

Runner
Prostate stems, such as those produced by strawberry plants, which root at the nodes to form new plantlets.

Scion
A shoot, part of a shoot, or bud of one plant that is joined to a rootstock of another as a propogation technique. Scions and rootstocks are the means of propagating fruit trees by grafting, and roses by budding.

Scree
A heap or a slope of rocky detritus eroded from mountainsides or cliffs. Since some types of plants require these conditions in a garden, a scree bed can be created by mixing coarse gravel or stone chippings with soil.

Selection
A particular variation of an existing variety or species that is selected for its desirable characteristics. It is always raised from seed. Also incorrectly referred to as a "strain".

Self Coloured
A flower having a single uniform colour.

Self Fertile
A plant, particularly a fruit tree, that does not need pollen from another plant to set seed and produce fruit.

Series
A selection or colour mixture of a plant variety (usually an annual, bedding plant or vegetable variety) raised from seed. A particular named series or mixture raised by two or more seedsman may vary slightly.

Serrated
The sharply cut indentations in the margin of a leaf - like the teeth of a saw.

Sessile
Stalkess - a leaf or flower that arises straight from the stem.

Shrub
A branched perennial plant with persistent woody stems.

Spadix
A fleshy flower spike with small flowers embedded in shallow pits. It is primarily found in members of the Araceae, or arpoid family, such as anthurium and zantedeschia, where it is surrounded and protected by a white or coloured bract called a spathe. In some cases, the spadix terminates in a naked club or spindle-shaped organ which may heat up, giving off a fetid smell that attracts pollinating insects.

Spathe
A modified leaf or large bract, sometimes coloured, which surrounds the flower spike (spadix) in members of the Araceae, or aroid family.

Species
A unit of classification applied to an individual, or a group of closely allied plants, within a genus. Species have unique characters, which consistently breed true to type from seed. The type species refers to the original plant collected and described.

Specimen Plant
Ant plant, but usually a tree or shrub, which is grown where it can be viewed from all angles, as when planted in a lawn.

Sphagnum (moss)
The generic name for bog mosses. They have unique water holding, aerating and cleansing properties, and are frequently used as a growing medium for orchids.

Spit
The depth to which soild is dug with a spade or a fork - about 25-30cm.

Spore
A minute dust like body composed of a single cell, by which lower plants - such as ferns, fungi and mosses - reproduce. A spore gives rise to an intermediate generation upon which the sex organs appear and which eventually produce plantlets.

Spur
1) A short lateral branchlet of a tree - particularly on apple and pear trees - which bears flowers buds
2) A tubular outgrowth of a sepal or petal that produces nectar

Staminode
A non fucntional, rudimentary male reproductive organ, sometimes similar to a narrow petal, as in pulsatillas.

Sterile
Plants that rarely or never set seed. Many double flowered varieties are sterile, as the reproductive organs have become petals.

Stipule
One of the pair of leaf like outgrowths at the base of a leaf stalk, for example, as in rose and potenilla.

Stolon
A stem which, on contact with moist soil, roots at the tip and forms a new plant - for example, the cane of a blackberry. The term is sometimes incorrectly used to mean RUNNER.

Stool
Often describing a tree or shrub which is maintained as a clump of young stems by annhual pruning clsoe to ground level. Stooling is carried out to provide young growth for propagation purposes, or to maintain a foliage effect, such as thr juvenile state of some eucalyptus. Also called 'coppicing'. The stem also applies to crowns and rootstocks of some herbaceous plants - dendrathema (crysanthemum) for example.

Stopping
Removing or pinching out the growing point of a stem, either to promote a branching habit or to induce flower buds.

Stratification
A method of breaking the dormancy of seeds born in fleshy fruits of many hardy plants. The seeds are exposed to a period of low temperature prior to sowing.

Sub Alpine
A plant native to mountain regions just below the alpine zone.

Sub Shrub
A low growing shrub, or one with soft stems and a woody base, such as argyranthemums and many pelargoniums.

Succulent
Plants with thick fleshy leaves or stems adapted to life under arid conditions. Cacti, with leafless stems swollen with water storage tissue, are examples.

Sucker
A shoot which arises from below ground, usually from the roots of a plant.

Synonym
An alternative name for a plant. Sometimes a plant has been named by more than one botanist or has been reclassified in the light of further knowledge. In such cases, the oldest or most taxonomically accurate name takes priority.

Tap Root
The main anchoring root of a plant, particularly applied to trees.

Tender
A term to describe any plant vulnerbale to frost damage.

Tendril
A modified stem or leaf that twines around supports, enabling certain plants such as sweet peas, grapes, hops and passionflowers to climb.

Tepal
A term used to describe petals and sepals where they are indistinguishable, as in lillies and tulips.

Ternate
In groups of three. Trillium has leaves and floral organs in groups of three, and laburnum leaves have three leaflets.

Terrestrial
Used in reference to plants, such as bromeliads and orchids which are primarily epiphytic, that have become adapted to living in the soil.

Tessellated
A term that describes petals which have a distinct chequered pattern of a contrasting shade or colour -, as for example, Fritillaria meleagris.

Toothed
Teeth like indentation, usually along the margins of leaves, also described as dentate.

Truss
A popular term used to describe a cluster of flower or fruits.

Tuber
A thickened fleshy root as on a dahlia, or an underground stem, such as a potato, which serves as a storage organ, and as a means of surviving periods of cold or drought.

Tufa
Soft limestone which, because of its ability to absorb and retain moisture, is often used in rock gardens or troughs, where small alpine plants are able to grow on it.

Tuft
Bristly, sometimes mat like, habit of growth, found particularly in alpine plants.

Gardening Definitions (N-P)

Naturalising
Growing plants, particularly bulbs, in simulated natural environments, such as grass or woodland conditions.

Node
A stem joint, which is sometimes slightly swollen, from where young leaves and side-shoots arise.

Offset
A young plant that arises naturally on the parent, as with many sorts of bulbs, or on short lateral stems, as with sempervivum.

Opposite
The arrangement of leaves in alternate opposite pairs, as on ligustrum and syringa.

Organic
Any chemical compound containing carbon. The term is applied to substances derived from the decay of living organisms, such as garden compost. It is also applied to a style of gardening that rejects the use of synthetic chemicals and products.

Pedicle
The stalk of an individual flower - applied particularly to branched flowers.

Peduncle
The stem that supports a flowerhead.

Perennial
Any plant that lives for three or more years; usually applied to a non-woody plant.

Perianth
A term used when sepals and petals are indistinguishable from each other. The combined sepals and petals of a tulip or hyacinth flower are known as the perianth.

Perlite
Lightweight expanded volcanic rock in granular form, used in place of sand or grit top open up or lighten composts used for pottings and cuttings etc.

Petiole
The stalk that attaches a leaf to the stem.

Pinching Out
Removing or pinching out the growing point of a stem, either to promote a branching habit or to induce flower buds.

Plunge
To set a pot or any other plant container up to the rim in the soil, or in a special bed of ashes, peat, grit or sand.

Pollard
A tree cut back to the main trunk and maintained in a bushy state by regular pruning at intervals of between one and a few years.

Pollen
The male cells of a plant contained in the anthers or pollen sacs.

Pollination
The transference of pollen grains onto the stigma of a flower. The resulting plantlets are later moved into larger pots, pans or trays, or set out into a nursery bed or into their growing position.

Provenance
The place where seed originated in the wild. Knowing the provenance will have a bearing on this conditions under which the progeny will thrive in cultivation.