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Achene - a small, one seeded fruit that does not split when mature.

Alternate - one leaf or bud arranged singly at each node on alternate sides of a stem.

Aeceospores - to have two nuclei.

Aspirator - a vacuum fitted with apparatus used to suck biocontrol agents into catch or collection containers.


Basal - at the base of a plant.

Basidia - club-shaped structures which produce spores on minute stalks.

Basidiaspoers - one of the spores produced on the basidium.

Basidium - club like structure, swollen terminal all where spores (generally 4) are produced.

Biennial - a plant that lives two years.

Biological control - using the plants natural enemies for control purposes, as in invasive plant control. Also known as biocontrol.

Biogeoclimatic zone - a coding system that groups similar parts of a landscape into an ecosystem.  Also referred to as Biogeoclimatic Ecosystem Classification (BEC).  The zones that are generally based on the tree species and represent the largest area.  The larger zone area further defined by subzones, variants and phases. 

Bolting - the stage in the lifecycle of a plant when the flower stalk begins to grow (bolt).

Bract - the small leaf structures growing below a flower. Bracts may be any color, but are usually inconspicuous. They are often referred to as modified leaves.


Capitulum - the seedhead part of plants in the sunflower family. The flowerhead appears as a single flower, but, actually is made up of numerous tiny flowers.

Capsule - a seedpod, which dries as it ripens and splits when mature to release the seeds.

Composite flower - flowers

Cuticle - a waxy layer found on plant leaves that help prevent desiccation and absorption.


Diapause - a biocontrol agents' dormant phase.

Disperse - to distribute over a wide area or become widespread.

Duff - decaying organic litter that accumulates on the soil surface under vegetation canopy.


Elytron (pl. elytra) - the hardened forewing or wingcover (front wing) of a beetle.

Emergence - the process referred to when an adult biocontrol agent vacates its pupal casing or appears after dormancy.

Epidermis - the outer tissue layers.

Exoskeleton - the outer skeleton of a biocontrol agent.


Flea-beetle - a type of beetle that has well developed hind legs that enable it to leap great distances.

Floret - a small flower, as found in the sunflower family where composite flowers produce a single flowerhead.

Frass - deposits made by feeding biocontrol agents consisting of plant pieces and excrement.


Gall - an irregular growth a plant develops as a reaction to an invading biocontrol agent.

Gravid - carrying unborn offspring inside the body.


Host specificity - the complex association between a biocontrol agent and its host plant

Hybrid - as in botany, a plant produced from a cross between two plants with different constituents.


Inflorescence - the flowering part of a plant.

Instar - a stage between the molts of a biocontrol agents' development.

Integrated pest management (IPM) - involves preventing invasive plant encroachment by: hand pulling; seeding; clipping; herbicide spraying and biological control.

Invasive Alien Plant Program (IAPP) Application - a database for invasive plant data in BC.




Larva - a biocontrol agents' stage of development, between egg and pupa.


Molt - the process biocontrol agents go through when they shed their skin in order to allow replacement of what is lost with new growth.

Monoculture - a single plant species occurring in a given area.

Multivoltine - having more than one generation/year.


Node - the point on a stem where leaves, shoots or flowers arise from.


Oviposit - to deposit or lay eggs, especially by means of an ovipositor.

Oviposition - the laying of eggs by means of an ovipositor.

Oviposition - an organ or set of organs at the end of the abdomen in certain female insects, by which eggs are deposited.


Pappus - a tuft of hair, scales or bristles that form at one end of a seed which also may assist with its dispersal.

Perennial - a plant that lives more than two years.

Primary - the biological control status level that is assigned as responsibility of Forest Practices Branch whom enables research andperforms development activities with the biocontrol agents.

Pubescence - short, fine hairs that cover a part of or all of a biocontrol agent or plant.

Pupa - the stationary stage of a biocontrol agent occurring between larva and adult.

Puparium - the casing that a pupa develops within.

Pycinal - rounded flask receptacle enclosing sexual reproductive spores.


Quiescent - Inactive or at rest.


Receptacle - the part of a flower (the capitulum) where the petals attach.

Rosette - the basal cluster of leaves of an immature plant.

Rostrum - a nose or snout of a biocontrol agent.


Sclerotia - sclerotium (plural).

Secondary - the biological control status level that is assigned as responsibility of Range Branch whom actively use the agents as treatment tools to manage invasive plants in the province. Additional agencies use secondary agents as treatment tools.

Senescence - when a life form declines and dies due to age.

Spermatium - the structure found around the spermi.

Sporolating - when a rust (fungus) forms spores.

Status - a term used to refer to any of the three biological control management responsibility designations: primary, secondary and tertiary.


Teliospores - overwintered spores with thick walls.

Tertiary - the biological control status level that is assigned to biocontrol agents that are more wide-spread around the province and are used as treatment tools by a wider range of agencies/clients when necessary or are left to spread further on their own accord.

Thorax - the part of a biocontrol agents body that occurs behind the head where legs and wings arise.


Uredia - singular for uredium

Urediniospores - Single cell orange-brown developing between teliospores and aeceospores (which have to nucleui)

Uredium - pistules bearing urediospores.

Univoltine - a biocontrol agent which has only one generation/year.



Weevil - a type of beetle, the adult form bearing a distinct elongated rostrum.





Wilson, L. M. and C. Bell Randall. 2003. Biology and biological control of knapweed.

Wilson, L. M., M. Schwarzlander, B. Blossey and C. Bell Randall. Biology and biological control of purple loosestrife.

"Healthy, functioning BC ecosystems, free of the impacts of invasive plants."