(Firethorn)

Transcription

(Firethorn)
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or visit: www.ecan.govt.nz/weeds
Firethorn
Pyracantha species
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weed of the month
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MAY
2014
Where is it found?
Identification
Evergreen shrubs up to 5 m tall with spines
along branches
Closely spaced oblong to ovate leaves up to
6 cm long
Masses of small, white 5-petalled flowers in
dense clusters in summer
Orange, red or yellow berries in autumn and
winter
All seven known species were introduced to
New Zealand: orange firethorn (Pyracantha
angustifolia), broad-leaved Firethorn
(Pyracantha crenatoserrata), Himalayan/
Nepalese firethorn (Pyracantha crenulata),
scarlet firethorn (Pyracantha coccinea),
Sichuan firethorn (Pyracantha atalantioides),
and Asian firethorn (Pyracantha rogersiana)
Orange firethorn (Pyracantha angustifolia) is
the only species that is banned from sale,
distribution and propagation in New Zealand
and can be easily identified by the furry
undersides of its leaves
Disturbed forest, shrublands, tussock grassland,
wasteland, roadsides, riparian areas and coastal
cliffs. It is a common ornamental shrub with
numerous cultivars.
Pyracantha cultivar.
Photo: M. von Tippelskirch
Why is it a problem?
Pyracantha produces masses of berries. The
seeds are commonly dispersed by birds. However,
the seeds can also be dispersed by mammals,
dumping of garden rubbish, and water. Pyracantha
has the potential to spread by layering, whereby
branches touching the ground re-root. The seeds
are moderately long-lived. Firethorn is very
adaptable to a wide range of soil and climatic
conditions. It can grow in dense impenetrable
thorny thickets, out-competing native species.
Similar species
Hawthorn is a related species and looks a bit
similar when in flower and also with its red berries
in autumn, but hawthorn leaves are deeply incised
with a serrated edge.
Pyracantha flowers.
Photo: M. von Tippelskirch
Control
Spray dense stands with metsulfuron-methyl or cut
and paste with glyphosate gel. Small plants can
be pulled. Plant treated areas with a permanent
cover of closely spaced shrubs or trees (for
example native kānuka, mānuka, Olearia, Corokia,
or Coprosma species or exotic camelias, Viburnum
and Ceanothus). Mulch heavily to prevent seedling
establishment. Pull seedlings until seed bank is
exhausted. Use all herbicides in accordance with
the manufacturer’s instructions and ensure no
herbicide comes into contact with other plants, the
soil or waterways.
Orange firethorn.
Photo: Weedbusters
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