Your gateway to a wide range of natural resources information and associated maps

Victorian Resources Online

Invasiveness Assessment - Rubber vine (Cryptostegia grandiflora) in Victoria (Nox)

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.

The following table provides information on the invasiveness of Rubber vine.

A more detailed description of the methodology of the Victorian Weed Risk Assessment (WRA) method can be viewed below:

Victorian Weed Risk Assessment (WRA) method (PDF - 630 KB)
Victorian Weed Risk Assessment (WRA) method (DOC - 1 MB)
To view the information PDF requires the use of a PDF reader. This can be installed for free from the Adobe website (external link).

Common Name: Rubber vine
Scientific name: Cryptostegia grandiflora

Question
Comments
Rating
Confidence
Establishment
Germination requirements?Seeds need between 5 and 15 days exposure to moist, warm (20-30C) conditions before they will germinate. Germination occurs following good rain (CRC for Australian Weed Management 2003).
MH
M
Establishment requirements?Establishment is enhanced by the presence of mulch on the soil surface (Parsons & Cuthbertson 2001). Plants tolerate shade and grow in a wide range of temperatures but are well adapted to a monsoonal climate (DNRME 2004). Wet shaded areas that protect the seeds from drying out are ideal with seeds readily germinating on riverbanks and other moist areas (CRC for Australian Weed Management 2003). However, the plant can also establish in dry forest (ISSG 2005).
MH
MH
How much disturbance is required?Plants are common in disturbed situations where there is temporary or permanent water, such as gullies, rivers, creeks, waterholes (IPIF 1999).
MH
MH
Growth/Competitive
Life form?It is a woody perennial vine (DNRME 2004). Climber.
ML
M
Allelopathic properties?None described in Parsons & Cuthbertson 2001.
L
MH
Tolerates herb pressure?It is poisonous to stock, however, if animal is stressed or other feed is scarce, they may eat it.

Biological control agents are being used (DNRME 2004).
MH
M
Normal growth rate?This plant aggressively colonises areas and forms thickets which can smother other vegetation (DNRME 2004). No evidence to suggest that it can exceed other species of the same life form but assumed that the growth rate will equal competitive species of same life form.
MH
M
Stress tolerance to frost, drought, w/logg, sal. etc?Does not occur in areas with more than 100 days frost per annum, and from 50-100 days frost per annum being a less suitable habitat. Needs absence of frequent fires to survive (Mackay 1996). Tolerant to water logging and drought tolerant up to 80 days. Survives in saltmarsh areas (ISSG 2005).
MH
MH
Reproduction
Reproductive systemPropagates by seeds – known to be insect-pollinated. Cannot vegetatively reproduce (Starr , Starr & Loope 2003).
L
MH
Number of propagules produced?Rigid seed pods (mostly grow in pairs) mature about 6 months after flowering and each contain an average of 350 brown seeds but can contain up to 450 seeds (DNRME 2004). Can produce more than 8,000 seeds in a single reproductive episode and can set seed at least twice per year (Starr , Starr & Loope 2003).
H
MH
Propagule longevity?Approximately 95% of seeds are viable (DNRME 2004).

Seeds remain viable for approximately 12 months (Starr , Starr & Loope 2003).
L
MH
Reproductive period?Individual plants have been known to live for more than 80 years (DNRME 2004).
H
M
Time to reproductive maturity?Plants can begin to reproduce after about 200 days although dependent on soil moisture, it can take more than four years to flower (Starr , Starr & Loope 2003).
H
MH
Dispersal
Number of mechanisms?As each seed has a tuft of long white silky hair, wind and water easily disperse them (via both fresh and salt-water courses) (DNRME 2004). Animals, especially birds, also spread the seed. Seeds can spread in mud sticking to machinery and in the hooves of animals – spreading along watercourses then to pastures and open country (Starr , Starr & Loope 2003)
H
MH
How far do they disperse?As seeds are very light with the tuft to aid dispersal, it is assumed that it is very likely that some propagules will disperse greater than one kilometre. Also bird dispersed (DNRME 2004).
H
M


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.
Page top