Back | Table | Feedback
Plant invasiveness is determined by evaluating a plant’s biological and ecological characteristics against criteria that encompass establishment requirements, growth rate and competitive ability, methods of reproduction, and dispersal mechanisms.
Each characteristic, or criterion, is assessed against a list of intensity ratings. Depending upon information found, a rating of Low, Medium Low, Medium High or High is assigned to that criterion. Where no data is available to answer a criterion, a rating of medium (M) is applied. A description of the invasiveness criteria and intensity ratings used in this process can be viewed here. |
Question | Comments | Rating | Confidence |
Establishment | |||
Germination requirements? | Establish early in the season before canopy closure can occur (Osem, Perevolotsky & Kigel 2006). Winter-spring annual, flowering in spring –summer (Cunningham et al 1981). Germination appears to occur on a seasonal basis. | MH | MH |
Establishment requirements? | Not specifically known. Reported to invade mallee and belah-rosewood communities, therefore tolerant of dry conditions and some level of shade (Cunningham et al 1981). | MH | M |
How much disturbance is required? | Can invade mallee (Cunningham et al 1981). | H | MH |
Growth/Competitive | |||
Life form? | Other; Annual forb (Cunningham et al 1981). | L | MH |
Allelopathic properties? | Unknown. | M | L |
Tolerates herb pressure? | Not specifically known. Grazing has been observed to have some impact on the density of the species, as the species is more abundant in ungrazed plots and in areas not associated with rabbit warrens. At what intensity grazing can eliminate the species is unknown (Cunningham et al 1981; Eldridge 2002; Osem, Perevolotsky & Kigel 2006). | M | L |
Normal growth rate? | Not sufficiently known in comparison to similar life forms. | M | L |
Stress tolerance to frost, drought, w/logg, sal. etc? | Occurs in semi arid environments, presumed drought tolerance (Osem, Perevolotsky & Kigel 2006). Other tolerances not sufficiently described. | M | L |
Reproduction | |||
Reproductive system | Flowers to produce seed (Cunningham et al 1981). | ML | MH |
Number of propagules produced? | Has numerous small seeds (Osem, Perevolotsky & Kigel 2006). It is not known specific seed quantities per flowering event. | M | L |
Propagule longevity? | Unknown. | M | L |
Reproductive period? | Annual species, with varying population dynamics year to year (Cunningham et al 1981). | L | MH |
Time to reproductive maturity? | Annual species (Cunningham et al 1981) | H | MH |
Dispersal | |||
Number of mechanisms? | Unknown. | M | L |
How far do they disperse? | Unknown. | M | L |
Feedback
Do you have additional information about this plant that will improve the quality of the assessment?
If so, we would value your contribution. Click on the link to go to the feedback form.