PIER (2005) details C. Parqui more descriptive characteristics as follows: \"A shrub, generally 1-3m high. Petiole to 1cm long. Lamina 2-12-(14) X 0.5-3cm, lanceolate to narrow-ovate, minutely puberulent when young, otherwise glabrous; base attenuate or cuneate; apex acute to short-acuminate. Inflorescence paniculate, dense; branches more or less puberulent; flowers subsessile or with pedicels to 7mm long, fragrant nocturnally. Calyx 3-6mm long; lobes 1mm long, more or less triangular, obtuse to subacute; margins shortly villous. Corolla 1.5-2.3cm long, greenish yellow or pale brownish yellow; tube narrow-salverform, widening slightly above; lobes 3.5-6mm long, narrow-triangular, patent, shortly villous inside and on margins, acute or short-acuminate. Fruit 7-10 X 6-8mm, broad-ovoid to broad-ellipsoid, glossy, black or purplish black (Webb et al. 1988, in PIER, 2005).\"
Principal source: QDNRM, 2005. Green cestrum: Cestrum parqui
Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG) with support from the Terrestrial and Freshwater Biodiversity Information System (TFBIS) Programme (Copyright statement)
Review: Dr. Neil Mitchell. School of Geography and Environmental Science. Tamaki Campus, University of Auckland. New Zealand.
Publication date: 2006-04-04
Recommended citation: Global Invasive Species Database (2024) Species profile: Cestrum parqui. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=850 on 08-12-2024.
QDNRM (2005) states that, \"C. parqui grows vigorously if neglected. On alluvial flats it has been known to outcompete most other vegetation. This species needs careful control because its extensive, shallow rooty system can produce many new plants from suckers, particularly after root disturbance or injury. C. parqui is toxic to animals including cattle, sheep, horses, pigs and poultry. Its effect on native fauna is unknown. Symptoms in cattle include fever, loss of appetite, increased thirst and eventually, general paralysis. Poultry develop acute kidney and liver damage. Post-mortem examination of poisoned animals usually reveals extensive internal haemorrhaging.\" Croft and Holding (2004) state that, \"The presence of this plant on many properties and in backyards means that there is the potential for children to gain access to plant material, especially seeds.\"
A Risk assessment of Cestrum parqui for Australia was prepared by Pacific Island Ecosystems at Risk (PIER) using the Australian risk assessment system (Pheloung, 1995). The result is a score of 11 and a recommendation of: reject the plant for import (Australia) or species likely to be of high risk (Pacific).
Mechanical: Croft and Holding (2004) state that, \"Mechanical control involves digging up plants by hand and removing all plant material including roots. Due to cestrum's ability to sucker from root fragments, follow up control is often required. Control using an application of mulch to cover and suppress seedling growth has been used. This method retains moisture in the soil and provides protection for native plants sown in conjunction with the mulching operation. It is used following chemical or mechanical control.\"
Chemical: Croft and Holding (2004) state that, \"Chemical control involves spot-spray application of herbicides and is used in heavy infestations to knock down mature stands. Alternatively a basal bark application with a dropper bottle can be used on isolated plants. Timing of treatment is important and should be done prior to setting seed. Suckering and seedling growth may occur so follow up treatment will be required.\"
QDNRM (2005) has listed a variety of chemicals used to control C. parqui in a variety of ways. Picloram & triclopyr (Grazon DSR) can be applied late spring to early autumn and to thoroughly cover all leaves and stems. Trichlopyr (Garlon 600R) can be applied if foliage is thoroughly sprayed when C. parqui growth is very active. Amitrole (Amitrole TR) can be used just prior to flowering and applications can be repeated if necessary until sufficient control is achieved. 2,4-D & picloram (Tordon 75-DR) can be used in spot treatment applications. And finally, Picloram & triclopyr-AccessR can be applied as a basal bark or cut stump application (QDNRM, 2005).
Biological: QDNRM (2005) states that, \"C. parqui seedlings can be suppressed by vigorous competition from other plants. Control adult plants, then plant a vigorous pasture species or local native species, which will compete with seedlings. This method is not always practical on riverbanks and gravel beds. This species can be killed by digging out the plants completely. Care must be taken to remove all the yellow roots, otherwise regrowth will occur. It is preferable to burn the roots.\"