The phenomenon in which one plant directly harms another (to reduce competition), particularly when
young through the production of chemical compounds released into the environment.
The selection, planting and care of individual trees, shrubs, vines, and other perennial, woody
plants, and the study of how they grow and respond to cultural practices and the environment. The
purpose is generally to manage woody landscape plants, often in a garden or urban setting, for plant
health and longevity, pest and pathogen resistance, risk management, maximum return on investment,
and ornamental or aesthetic reasons. In this, it needs to be distinguished from forestry, which is
the commercial production and use of timber and other forest products from plantations and forests.
The resultant hybridism is between two (2) species from different (yet related) genera. In terms of
botanical nomenclature plants of this nature should be written with the 'x' indicating the hybridism
before the genus name. For example: x Cupressocyparis leylandii
Layer of actively dividing cells between the bark and the wood.
The green photosynthetic pigment found in plants,
algae, and cyanobacteria. Its name is derived from ancient Greek; chloros
= leaf. Chlorophyll absorbs mostly in the blue and to a lesser extent
red portions of the electromagnetic spectrum, thus its intense green color.
An unhealthy condition shown by yellowing of foliage
or shoot tips. Occurs when chlorophyll is destroyed or its formation is inhibited by
nutrient deficiencies, drought, disease or other environmental factors.
Having unisexual flowers; male and female on different plants.
Formed when dormant foliage buds on the trunk and branches are activated as a result of
environmental stress or injury to the original crown. Best examples seen on the
A genus or genera of plants having a number of taxonomic features in common.
For example: Myrtaceae
(Myrtle Family) or Araucariaceae
Trees are girdled when the flow of food material in the inner bark and phloem is
stopped, usually as a result of continuous incision or damage around the trunk of
the tree, through the bark and cambium. The effect is usually fatal within two to
A special branch of a hypha of a parasitic (or partly parasitic) fungus or plant,
adapted to absorb water and mineral nutrients from the host, particularly from living
cells; for example Amyema pendula
The dense and often dark-coloured wood that lies in the inner part of the trunk or
branch that is devoid of living cells. Toxic waste materials are usually deposited
in the heartwood giving it durable qualities.
The progeny resulting from the crossing of two related parents of different species,
usually of the same genera, and occasionally different genera. The name of such a
plant should be written as such Acer x freemanii
Originating in and characterising a particular region, area or country.
A viscous, reddish, black liquid developed in the cambial zone, notably of Eucalyptus
, as a result of injury. They are rich in tannons (polyphenols) which can
be phytotoxic to fungi.
A woody swelling, partly or wholly underground at the base of the stem of certain plant species,
notably many Eucalypts. It is composed of energy reserves and dormant buds which can emerge
as a survival response to an externally applied stress eg: fire, drought or soil compaction.
There are hundreds of species of Longicorn Beetles that attack both trees and shrubs. Fortunately,
most are confined to dead limbs and fallen trees. However, some are serious pests of weakened and/or
injured trees, causing their death by ring barking. The eggs of these beetles are laid in the bark,
usually in injuries or fire scars. The young larvae hatch and feed initially in the phloem/cambium
region. Larva move into the sapwood and/or heartwood and may travel for 1-3m where it will make the
characteristic hole in the sapwood just beneath the bark. Trees may live for several years under
attack from this pest, however the tree often becomes unsafe as the trunk(s) may snap at a weakened
point where larva may have concentrated their activities.
A group of localised, dividing cells, which produce active growth; this could occur either at
the root and shoot tips or in the trunk (lateral growth).
With unisexual male and female flowers on the one plant.
An organic or sometimes inorganic product that is placed on top of the existing soil surface
around plants to perform a number of functions such as weed suppression, aid in the regulation
of soil temperature and moisture levels and to improve landscape aesthetics. Mulches can be made
from a variety of materials however organic products such as wood chips and straws are useful as
they decompose over time adding organic matter to the soil and improve soil structure.
A symbiotic association between a fungus and a higher plant, most often consisting of an intimate
relation between the plant's roots and the fungal mycelium.
Essential for healthy vegetative growth and is also used on the formation of chlorophyll and protein.
The word Palm should be used as opposed to the commonly used phrase 'Palm Tree' as Palms are not trees
by definition as they do not form wood as a tree does, nor do they form bark. Palms have a hard stem
that contains bundles of conductive vessels scattered throughout softer tissue. Secondary thickening
of the stem is absent, or slight, and even then it is not cambial but from divisions in the ground
parenchyma. This type of structure not only provides the Palm trunk with strength but also stability.
Palm root systems are also not woody like a tree and they invariably do not 'branch'. Therefore the
phrase 'Palm Tree' is a contradiction in terms and we should more correctly just say 'Palm'.
A parasite capable of producing disease in its host.
Specialised tissue for transporting materials around a plant; usually
situated between the bark and the wood.
The first formed root of a seedling, from which the primary plant root develops.
The region of the plant where the major roots arise; the transition zone between
the stem and the root, sometimes recognisable by a slight swelling.
A fungus or plant that lives exclusively on dead plant or animal matter, commonly assisting its decay.
Newly formed wood; characterised by the presence of living tissue, which store energy and an absence
of plant waste products. Usually light coloured.
The term first used by Anton de Bary in 1879 to describe two unlike organisms living together
beneficially (symbionts), eg; lichens and mycorrhiza.
Visible evidence of disturbances in the normal growth development of a plant.
The system and procedure of biological description, classification and nomenclature.
A woody plant growing to a height of 5 metres or more, often displaying a main trunk and somewhat
symmetrical canopy. The lower part of the trunk can be free of branches for some distance.
A generic word for a plant growing in a location where it is not wanted. Weeds become of environmental
and economic significance in connection with natural bushland and agriculture, where they may displace
and/or out compete the native flora or damage crops when growing in fields and may poison domesticated
and/or native. Many weeds are short-lived annual plants that can produce copious numbers of fertile
seed that are easily dispersed. Many weed species take advantage of temporarily bare soil
(or mostly so) to produce another generation of seeds that in many cases can be stored in the
soil for long periods of time and can be activated into growth when environmental conditions are
conducive to their growth.