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 | Reference | Rating |
Establishment | |||
Germination requirements? | See H. aurantiacum. See also Carson & Pickett (1990) CAB abstract. | MH | |
Establishment requirements? | See H. aurantiacum. Forest infestations occur in Idaho. “While most apparent in open areas, forest infestations prevent natural seeding of trees & native plants.” | HACI (1999) | MH |
How much disturbance is required? | See H. aurantiacum. See also above. | MH | |
Growth/Competitive | |||
Life form? | Perennial herb. Creeping stolons / runners. Geophyte. | AQIS (1996) Callihan et al (1997) Muenscher (1955) | ML |
Allelopathic properties? | Pollen allelopathy unlikely to affect other species. Minor properties likely as allelopathy is notable among other plants of this genus. | Murphy & Aarssen (1995) CAB abstract | ML |
Tolerates herb pressure? | See H. aurantiacum. | MH | |
Normal growth rate? | See H. aurantiacum. Also see Toney et al (1998) CAB abstract | H | |
Stress tolerance to frost, drought, w/logg, sal. etc? | Frost (occurs in south island of New Zealand). Also likely drought tolerant. | Callihan et al (1997) Webb et al (1988) Carson & Pickett (1990) | MH |
Reproduction | |||
Reproductive system | See H. pilosella. | Muenscher (1955) Callihan et al (1997) | H |
Number of propagules produced? | See H. aurantiacum. | ML | |
Propagule longevity? | See H. aurantiacum. | L | |
Reproductive period? | See H. pilosella. | H | |
Time to reproductive maturity? | See H. aurantiacum. | MH | |
Dispersal | |||
Number of mechanisms? | See H. pilosella. | H | |
How far do they disperse? | See H. aurantiacum. | MH |
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.