Auckland Weedspotters
Network
SEPTEMBER 2014 UPDATE
These updates may have stopped for a while but the weeds certainly haven’t. All the usual suspects are still making their presence felt all over Auckland (and further afield) – moth plant, pampas, woolly nightshade etc etc. There are also a few newer
ones like Phragmites karka or the batwing passionflower (passiflora apetala). And as mentioned to the Pest Liaison Group and
the Botanical Society, we are also on the lookout for plant diseases —particularly Myrtle Rust (featured further on in this
newsletter). Also featured this update is the current list of Total Control plants from the Regional Pest Management Strategy.
What weeds should I look for?
Bat-wing Passionflower
The main weeds we want to know about are any of those on
the Total Control list of the Regional Pest Management Plan
(the list is at the end of this newsletter). Some examples are
Salvinia molesta, bat wing passionfruit, water hyacinth and
chinese /asiatic knotweed.
There are others we have our eye on, including those on the
National Pest Plant Accord list. The full list is on the Ministry of
Primary Industries (MPI) website under the (NPPA).
Kerry Bodmin from NIWA also has a list of aquatic weeds that
may be coming our way from places like the USA. A few of
those are:
Aquatic or wetland plants already here in NZ with limited
distribution
a.
Water hyacinth (Eichhornia crassipes)
Greg Hoskins (Senior Biosecurity Advisor, Auckland Council)
Bat-wing passion flower (passiflora apetala), is an invasive
vine species that has been confirmed in the Northland, Auckland and Waikato regions. It has the ability to smother, shade
and strangle other plants and is seen as an emerging threat to
New Zealand’s environment (some closely related Passiflora
species have become serious weeds in New Zealand).
Greg Hoskins
Batwing passionflower seedlings
The vine was introduced as an ornamental variety in the mid1990s and has been dispersed in New Zealand through the
activities of sub-tropical plant collectors and birds which find
the berries very attractive to eat. Native to Costa Rica and
Panama, it grows at elevations of 1300-2200m.
In NZ it grows at lower altitudes and appears to be shade
tolerant. Its leaves have two large lobes making it look like a
bat’s wing and some have pale green stripes along the midribs. It has small yellow-green coloured flowers 12-20mm
diameter and produces small purplish black berries roughly
the size of a small grape 7-15mm diameter.
a
c
b
b.
c.
d.
Phragmites
(Phragmites australis)
Purple loosestrife
(Lythrum salicaria)
Royal fern (Osmunda
regalis)
d
Aquatic or wetland plants found in the US but not currently
known in NZ
a.
Eurasian water-milfoil (Myriophyllum spicatum)
b. Fringed water lily (Nymphoides peltata)
c.
Broadleaf cattail (Typha latifolia)
d. Narrow leaf cattail (Typha angustifolia)
e. Western waterweed (Elodea nuttallii)
The vine is an abundant fruiter, and seed is dispersed by birds.
Flowers and fruit have been found all year round in New Zealand with the minimum temperature for growing about 5 ° C.
Weedspotters Network winter update September 2014
Page 1
A mature vine (2-3 years old) can produce more than 3000
fruit with an average of 15 seeds per fruit. Plants grow rapidly
from seed and can flower in 24 weeks with fruit maturing after
32 weeks.
Seeds collected from vines have a viability of around 90%
and appear quite resistant to the aging process – and are likely
to remain viable for more than 10 years in the natural environment. This seed longevity indicates an eradication programme would need to run for 15 years.
Flowers of the
Batwing
I also like working on cathedral bells as it is a very beautiful
plant – the flowers look like dignified cups and saucers, and
the vines hang gracefully from trees – it is little wonder it was
once sold as a garden plant. Unfortunately it is a love / hate
relationship because it is a plant that has jumped the garden
fence to become a serious pest.
The problem with cathedral bells is that it has a tendency to
take over any patch of land that it comes into contact with; it
is the femme fatale of the plant world and will quickly take
over if you turn your back on it. It tolerates both sun and
shade, and has extraordinary growth rates that will see it
quickly climb and smother trees.
passionflower
Cathedral
Bells
seedling
Bat-wing passion flower has been found regenerating in native
and exotic forests, scrub, home gardens and amongst hedges
and fence lines. Seedlings are usually found under fruiting
vines and places where birds perch.
Roots can be hand pulled or grubbed out and stems tied
above the ground to prevent layering. Also stems can be cut
at ground level and stump treated with an appropriate cut and
paste herbicide. Large masses on the ground could be
sprayed with glyphosate where roots cannot be pulled. Remove all fruits from the vines to prevent seeding and regularly
visit sites to check for seedlings.
In 2009 the vine was declared an unwanted organism under
the Biosecurity Act 1993, which bans it from sale, propagation
and distribution.
It can take over in both the urban environment and deep in
shaded native forest. Unlike blue morning glory, it can seed
and spread itself by wind, soil and water.
Cathedral bells is a Total Control plant, which means that
Auckland Council Biosecurity is responsible for the cost of controlling it and for the survey work required to eradicate it from
the region, when new sites are found.
The key identification features are the distinct purple cup
and
saucer flower and the green passionfruit shaped
The ‘femme fatale’ of the plant world?
seedpods.
The pale green leaves are soft and slightly fleshy
Kate Leggett (Biosecurity Advisor, Auckland Council)
and smell a little like snow peas when crushed.
One of my favourite plants to work on as a biosecurity advisor
The leaves look slightly like wisteria leaves when they are
is cathedral bells (Cobaea scandens). The reason why I like it is
young, slightly like honeysuckle leaves when they are older.
because it is a thoroughly polite plant to kill. It doesn’t make
The growing tips of the young plants have fine reddish-purple
you cough (like woolly nightshade), doesn’t make you itch (like
tendrils; the stems can be quite angular on larger plants.
moth plant), doesn’t make you sneeze (like privet), doesn’t
attack you with prickles (like gorse), doesn’t slime you with its
ooze (like agapanthus) and doesn’t make you smell funny for
the rest of the day (like lantana). The other joy about cathedral bells is that once it is dead it tends to stay dead.
A small plant can become a large plant very quickly. It flowers
between August and May – so keep an eye out for it from
around now until the end of autumn. We tend to get reports
of a couple of new sites each year across the Auckland region
with the most recent report early in 2014 from Mission Bay.
If you see it please take a photo or a GPS point and ring the
council on 301 0101 and let Biosecurity know. You can also
contact us at [email protected]
Weedspotters Network winter update August 2014
Page 2
Phragmites karka — hopefully not coming to a
place near you!
P. karka ligule hairs
Tahapa Road site
Although there are only two known sites of Phragmites karka
in Auckland, the indications are that it has been here for some
time and there may well be more.
The initial report in 2011 came from Mike Wilcox; he had
seen it in Meadowbank behind some properties on Tahapa
P. karka
Crescent, and thought it may be P. australis. The site covered
seed head
295m² above ground on three properties, and the widest part
was eight metres. One of the residents said it had been there
If you see it , please take photos and a PS point and ring
the whole 15 years he had lived there, and in the last four
the council on 301 0101 to inform Biosecurity. You can also
years it had spread substantially into his property. The rhicontact us at [email protected]
zomes were found to have spread six metres out under the
lawn from the nearest visible reeds.
Samples taken by Paul Champion from NIWA were not a
Curator’s corner
genetic match to any material held at Landcare Research. The (Ewen Cameron, Botany curator, Auckland War Memorial museum)
decision was made to remove the plant from the site entirely, Aristea (Aristea ecklonii) - a blue-flowered native African iris
and this was carried out in early September 2012. The site
I want to bring to
continues to be monitored.
your attention a plant
that most of you will
know, but possibly
are not aware of its
full weedy potential.
Aristea is currently
classified under
‘Surveillance’ in the
RPMS and also as an
Unwanted Organism
with MPI. It has been
Wattle Farm site
growing on sunny roadside banks of Helensville and the road
to Muriwai for over 55 years. As well as other areas it turned
The second site was found by Paul in February 2014 at the
up in the Waitakeres in 1979, Little Huia 1989, Woodhill in
Wattle Farm ponds reserve in Manurewa. Although positive
2000, Great Barrier Island 2002, Whatipu 2003 and a remote
identification is still pending, the plant is considered to be
native area on Tiritiri Matangi 2013. It appears to require full
P. karka until confirmed otherwise, and is being actively
sun to open its attractive blue flowers. The capsules produce
controlled. The plant was not a newcomer to the site, and the copious small seeds which are dispersed by water and readily
Stormwater team had been controlling it prior to establishing germinate. Once seeded it is difficult to eradicate.
the native planting, thinking it was bamboo. It may have been
I recently saw it invading a narrow gully in Woodhill Forest
spread around other sites as mulch following clearance; what under a canopy of kanuka [image attached]. It is concerning
isn’t known is where those sites may be. Outside of Auckland, how shade tolerant this plant is and the speed it can expand.
it is known to be in the Rangitikei area, but is not currently
How it got to the eastern side of Tiritiri is a mystery.
being controlled.
Aristea is: tolerant of different soil types (clay, sand); thrives
So what do you need to look out for? P. karka may at first
in full sun to moderate shade; able to rapidly multiply (by seed
glance look like an Arundo species, like A. donax. Established or rhizome); able to form dense swards and smother small
stands like the Tahapa Road site may be up to four meters
plants/whole habitats; and it is still absent from much of the
high and several metres wide. It will be growing in / near
region. Because of this I believe it’s time that a biological
drainage and wet areas. The seed heads are golden brown
control agent should also be investigated for aristea.
and feathery, similar to pampas but much less dense. Leaves Weedspotters can assist by eradicating small populations
are attached directly to the stalk, and ligule hairs are present. when seen.
Weedspotters Network winter update August 2014
Page 3
Disease of the month — Myrtle Rust
A happy accident?
Plant diseases are just as much of a concern, not only because
of their threat to our native flora ie kauri dieback, but also to
our our primary production industry and amenity horticulture
values. The kiwifruit Psa-V bacterium, and Dutch Elm disease,
are good examples of this.
The new kid on the block this spring is Myrtle Rust, as featured at the August Botanical Society and Pest Liaison Group
meetings. It originates from South America and was discovered in Australia in 2010. It has spread quickly and is already
established along the east coast in New South Wales, Queensland and Victoria.
There may be a biocontrol for Californian thistle (Cirsium arvense) in New Zealand and we didn’t even realise! Michael
Cripps from Agresearch in Lincoln is leading a project on the
investigation of ‘white tip’ of Californian thistle here, and
wants to know if you see any thistles displaying symptoms.

Phoma macrostoma is a cosmopolitan fungus, and is
pathogenic to a wide range of broadleaf and woody plant species, but non-pathogenic to most grasses.

Recently, in Canada a strain of P. macrostoma has been
registered as a bioherbicide for control of broadleaf weeds,
including Californian thistle (Cirsium arvense).

“White tip” disease symptoms have been observed on
Californian thistle in New Zealand, but it’s unclear if the causal
agent is P. macrostoma.
In 2013 it blew from Queensland to New Caledonia where it
has been found infecting many susceptible plants. Myrtle
rust spores travel very long distances by air and are capable of
invading and surviving across the Auckland Region and other
areas around New Zealand. A butterfly from the same region
in Queensland as where the rust has established has been
found at Wenderholm, likely to have blown over with Tropical
Cyclone Ita a few months ago. If that is here, the rust is likely
to be too.
Myrtle Rust diseases are notoriously difficult to control and
has not been eradicated anywhere it has established. This
rust affects leaves, flowers and fruit of a wide range of the
myrtaceae family – which includes not only our natives like
pohutukawa, leptospermum, lophomyrtus etc but exotics like
guava, feijoa and also acmena, eugenia, syzygium and eucalyptus.
Above: Symptoms of
“white tip” disease on
Californian thistle, in
Pahiatua
Left: Californian thistle
(Cirsium arvense) in
Canada showing typical
photo-bleaching symptoms of “white tip”
disease caused by the
pathogen, Phoma
macrostoma.
The bleaching caused by white tip disease in thistle is quite
distinct on the newest leaves. Often just the plant tips are
white, with leaves below the normal healthy green. This is not
to be confused with Californian thistle rust (Puccinia punctiformis) which while it can cause the leaves to become pale,
the underside is covered by rust coloured pustules.
Myrtle rust (Puccinia psidii) is a fungus that attacks the new
A biological control for Californian thistle would be very
growth leaves, shoots and flowers of native Myrtaceae species useful for many New Zealand farmers. However, with NZ’s
and also the introduced eucalyptus, guava and feijoa. In order strict phytosanitary requirements, the potential for white tip
to establish on a host plant it only requires moist warm condi- to be approved for use here would be considerably higher
tions and six hours of darkness—Auckland certainly qualifies
were it to be already present in our environment. So if you
for this!
plants displaying the symptoms, please send whole plant
The rust will generally appear as bright yellow spots on the
samples to Michael Cripps at Agresearch, Lincoln Research
new growth, flower buds or even on the fruit of some plants. Centre, Private Bag 4749, Christchurch 8140 (ph 03 325 9936).
It could kill the new growth completely, cause brown spots on
the upper leaves and holes in the leaves. The fruit could fail
If you have any questions about anything you’ve read here,
to develop, and even fall from the tree. The rust can appear
or if you’ve found something you think we should know
red when the sexual types of spore are being produced.
about, please don’t hesitate to get in touch. You can email
Do not touch or collect samples as this may spread the
me at [email protected] or call me on
disease.
Report any red or yellow looking rust on the undersides of
890 7901 or 021 942 857
newly growing leaves, on the buds or flowers of Myrtaceae
Jane Sparkes, Regional Biosecurity Advisor (Community)
plants to MPI immediately on 0800 80 99 66, and let the
Auckland Council
Biosecurity team know of the affected area.
Regional Pest Management Strategy Total Control Plants
Unless specified otherwise, all these plants are Total Control (TC) over the whole Auckland region.
COMMON NAME
SCIENTIFIC NAME
African feather grass
Pennisetum macrourum
Asiatic knotweed
Reynoutria japonica syn. Fallopia japonica, R. sachalinensis syn. F.
sachalinensis & hybrids
Asparagus species
Asparagus drepanophyllus & A. umbellatus
Asiatic
knotweed
Balloon vine & small balloon
Cardiospermum grandiflorum & C. halicacabum
vine
Broomsedge
Andropogon virginicus
Cathedral bells
Cobaea scandens
Chilean needle grass
Nassella neesiana
Climbing spindle berry
Celastrus orbiculatus
Devil’s fig
Solanum torvum
Devil’s tail
Persicaria perfoliata syn. Polygonum perfoliatum
Egeria
Egeria densa
TC on Great Barrier Island only. Surveillance everywhere else.
Great reedmace
Typha latifolia
Green cestrum
Cestrum parqui
Houttuynia
Houttuynia cordata
Kudzu vine
Pueraria montana syn. P. lobata
Lantana
Madeira vine
Devil’s tail
Kudzu vine
flower
Lantana camara
TC in rural areas only. Surveillance everywhere else.
Anredera cordifolia
TC in defined areas only. Surveillance everywhere else.
Manchurian wild rice
Zizania latifolia
Marshwort
Nymphoides geminata
Mexican feather grass
Nassella tenuissima
Nassella tussock
Nassella trichotoma
Needle grass
Austrostipa rudis
Old man’s beard
Clematis vitalba
Purple loosestrife
Lythrum salicaria
Rhamnus
Rhamnus alaternus
TC in defined areas only. Containment (boundary) in Rhamnus mainland zone. Surveillance everywhere else.
Royal fern
Osmunda regalis
Sagittaria species
All Sagittaria spp. (except S. teres)
Scrambling lily
Geitonoplesium cymosum
Senegal tea
Gymnocoronis spilanthoides
Spartina
Spartina alterniflora, S. anglica & S. x townsendii
TC in defined areas only. Surveillance everywhere else.
Water poppy
Hydrocleys nymphoides
White-edged nightshade
Solanum marginatum
Wild broom
Cytisus scoparius (excl. cultivated varieties)
TC in rural areas only. Surveillance everywhere else.
Old man’s
beard
Spartina