invasive weed 3: Silver-leaf nightshade

Name: Silver-leaf nightshade
Scientific name: Solanum elaeagnifolium
Other names: Silver-leaf nettle, silver-leaf bitter apple
Level: Category 3 restricted invasive plant

The Silver-leaf nightshade is a deep-rooted perennial plant that is native to North America. This multi-stemmed plant that grows up to 60cm tall. Small spines up to 5mm long grow on the stems and petioles and leaves are silvery green with pale underside, 5-10cm long and have wavy edges. Silver-leaf nightshade has 5 purple/white flowers up to 25mm in diameter with 5 yellow stamens. Berries of the nightshade plant are green striped, round and smooth that turns yellow/orange when ripe and seeds are light brown, rounded, flattened with irregular surface (AJ, 1988).

Figure 1: Silver-leaf Nightshade berries

Figure 2: Nightshade leaves and stem with spines 

Figure 3: Nightshade flower

Silver-leaf Nightshade disperses its seeds in a number of ways. Seeds can be spread by animals such as birds as they feed on the fruit and take the seeds to new areas. During summertime, plants can grow from seeds and roots while in wintertime, the plant grows mostly from the roots. Roots can be spread by cultivation by the machinery as new plants can grow from roots as small as 1cm. This plant can grow in any soil type allowing it to have a wide range of habitats and can be found in Southern east Queensland (Stanton & Lemerle, 2012).

Silver-leaf Nightshade is a category level 3 invasive plant and is difficult to control/remove. The Silver-leaf Nightshade has an extensive interconnecting root system which is difficult to remove as they have the capacity to regenerate from root fragments. Good farm hygiene is mandatory to help stop the spread of seeds and roots. There is currently no biological control for this weed.

References

AJ, W. 1988, "Prospects for the biological control of silver-leaf nightshade, Solanum elaeagrifolium, in Australia",

Stanton, R., Wu, H. & Lemerle, D. 2012, "Factors Affecting Silverleaf Nightshade (Solanum elaeagnifolium) Germination", Weed Science, vol. 60, no. 1, pp. 42-47.

https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/weeds-diseases/invasive-plants/restricted/silver-leaf-nightshade retrieved 27/04/2020

Invasive weed 2: Cat’s claw creeper

Name: Cat’s claw creeper
Scientific name: Macfadyena unguis-cati (L.) A.H.Gentry
Other names: syn. Dolichandra unguis-cati (L.) L.Lohmann
Level: Category 3 restricted invasive plant

The Cat’s claw creeper is a woody climbing vine that is native to Central and Southern America. The stems are long and slender with older stems becoming woody over a period of time. Cat’s claw creeper leaves have 2 leaflets with 3-clawed tendrils called cat’s claw that are 3-17mm long. The vine has large, bright yellow, bell-shaped flowers and bears exceedingly long, narrow and flat seed pods that contain papery seeds (Shortus & Dhileepan, 2010).

Figure 1: Cat’s claw creeper flower

Figure 2: Cat’s claw creeper leaves with clawed tendrils 

Figure 3: seed pods

Due to the design of the Cat’s claw creeper seeds, the seeds travel mostly by wind due to their papery wings. The seeds can also be dispersed by water ways and rivers. Cat’s claw creeper plant also has tuberous roots that can also be spread by floods and by attaching themselves on animals and humans. This species prefers warm temperate, tropical and subtropical areas and is found in south-eastern Queensland and north Queensland(Taylor & Dhileepan, 2012).

As Cat’s claw creeper is a category 3 invasive plant, efforts to slow the spread have been made. A physical control is by using pruning saws/machete/brush hooks to remove leads/stems up the tree, however regrowth can occur from underground tubers. The tingid bug Carvalhotingis visenda, the moth Hypocosmia pyrochroma and a leaf-mining jewel beetle Hylaeogena jureceki are been used as a biological control of the Cat’s claw creeper by feeding on it (business.qld.gov, 2020).

References

Shortus, M. & Dhileepan, K. 2010, "Two varieties of the invasive cat's claw creeper, 'Macfadyena unguis-cati' (bignoniaceae) in Queensland, Australia", Proceedings of the Royal Society of Queensland, The, vol. 116, pp. 13-20.

Taylor, D.B.J. & Dhileepan, K. 2012, "Comparative growth and biomass allocation of two varieties of cat's claw creeper, Dolichandra unguis-cati (Bignoniaceae) in Australia", Australian Journal of Botany, vol. 60, no. 7, pp. 650-659.

https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/weeds-diseases/invasive-plants/restricted/cats-claw-creeper retrieved 27/04/2020

Invasive weed 1: Blackberry

Name: Blackberry
Scientific name: Rubus anglocandicans, R. fruticosus agg.
Other names: European Blackberry
Level: Category 3 restricted invasive plant

The Blackberry is a woody, shrub that grows in thickets and is characterized by their reddish-purple stems with numerous hooked thorns. Leaves of the Blackberry shrub are dark green on the upper side, whitish underside and has hooked thorns on the leave stalks. Flowers are white or pink, 2-3cm diameter and form clusters at the end of branches. Blackberry fruit changes from green to red to black with each segment containing one seed (business.qld.gov, 2020).

Figure 1: Blackberry fruit

Figure 2: Blackberry flowers

Figure 3: Blackberry stalk with thorns 

Blackberry seeds are spread mostly by animals such as foxes and birds as they feed on the fruit and take the seeds to new areas. Seeds can also be dispersed by water ways, creeks, gullies and rivers (Aghighi et al, 2014). Stems of the Blackberry plant are able to send out roots, forming daughter plants and expanding the infestation. In Queensland, blackberry plants occur in Stanthorpe, Warwick, Killarney and Toowoomba areas and prefers temperate habitats(Gomez et al, 2008).

In effort to control the spread on the Blackberry plant, small plants are pulled out of the ground and dispose by burning. Slashing/cultivation/burning Blackberry plants when appropriate and replace with native vegetation to help slow the spread. A rust fungus can slow the rate of spread but does not kill the weed and should not be relied on as an adequate control (business.qld.gov, 2020).

References

Aghighi, S., Fontanini, L., Yeoh, P.B., Hardy, G E St J, Burgess, T.I. & Scott, J.K. 2014, "A Conceptual Model to Describe the Decline of European Blackberry (Rubus anglocandicans), A Weed of National Significance in Australia", Plant disease, vol. 98, no. 5, pp. 580-589.

Gomez, D.R., Evans, K.J., Baker, J., Harvey, P.R. & Scott, E.S. 2008, "Dynamics of Introduced Populations of Phragmidium violaceum and Implications for Biological Control of European Blackberry in Australia", Applied and Environmental Microbiology, vol. 74, no. 17, pp. 5504-5510.

https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-diseases/weeds-diseases/invasive-plants/restricted/blackberry retrieved 26/04/2020

Introduction

Hello everyone,

This blog is about invasive plants that are currently in Australia. As there are many plants species that are invasive, this blog will be covering the description and characteristics of the plant, how it spreads and if there is any control methods available.

Disclaimer: All information belong to their relative sources.