field identification guide - weeds...
TRANSCRIPT
Field Identification GuideAustrocylindropuntia, Cylindropuntia and Opuntia species
Contents
Invasive cacti fACts 02
The problem 04
The weed 06
Weed identification 08
Growth pattern in suitable conditions 10
Species identification 11Key to symbols 11
Glossary 11
How they spread 52
Where they grow 53
What to do about them 53
Spread prevention 53
Chemical control 54
Fire 56
Grazing 57
Mechanical control 58
Biological control 58
Legislation 60
Weed control contacts 61
Acknowledgements 62
Key references 62
Information and guide revision 63
SpeCIeS IdenTIFICATIon Index
Austrocylindropuntia cylindrica 12 Cane cactus
Austrocylindropuntia subulata 14
Cylindropuntia fulgida var. mamillata 16 Coral cactus, boxing glove cactus
Cylindropuntia imbricata 18 Devil’s rope/rope pear
Cylindropuntia kleiniae 20
Cylindropuntia leptocaulis 22 Pencil cactus
Cylindropuntia prolifera 24 Jumping cholla
Cylindropuntia spinosior 26
Cylindropuntia rosea 28 Hudson pear (White-spined)
Cylindropuntia tunicata 30 Hudson pear (Brown-spined)
Opuntia aurantiaca 32 Tiger pear
Opuntia elata 34 Riverina pear
Opuntia elatior 36
Opuntia engelmannii 38
Opuntia ficus-indica 40 Indian fig
Opuntia microdasys 42 Bunny ears or Golden bristle cactus
Opuntia monacantha 44 Drooping tree pear
Opuntia robusta 46 Wheel cactus
Opuntia stricta 48 Common prickly pear
Opuntia tomentosa 50 Velvet pear
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
ii 01
•Invasive cacti impact on Australia environmentally, agriculturally and aesthetically, as well as posing a risk to animal welfare and human safety.
•Invasive cacti are drought resistant and hardy, surviving in low rainfall environments.
•They spread easily by seed (in some species only) and by stem segments (fragments) that root readily to form new plants.
•opuntioid cacti vary significantly in their form and habit, ranging from low-growing shrubs under 50 cm to erect trees up to 8m tall.
•Species are found throughout most Australian states and territories and there is potential for further spread.
•Australian rangelands are especially vulnerable to cacti invasion.
•The cost of control often exceeds the value of land infested.
•All cacti are exotic to Australia.
Invasive cacti fACtsSh
AUn
A Po
tter
Opuntia tomentosa
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
02 03
The problemThree types (genera) of opuntioid
cacti have naturalised in Australia and
are now considered Weeds of National
Significance: Austrocylindropuntia,
Cylindropuntia and Opuntia.
Dense infestations compete with native
vegetation, limiting the growth of small shrubs and
groundcover species. The plant’s sharp spines or
barbs can cause injury to stock and native animals
and contaminate wool and hides, reducing or
preventing grazing activities and productivity.
Large stands of cacti provide harbour for pest
animals, such as foxes and rabbits and, due to their
spiny nature, can limit access for stock mustering
and recreational activities. The spines are capable of
causing serious injury to animals and humans.
Plant segments kept in sealed containers have been
known to survive indoors for three years without
soil or water, demonstrating their ability to persist
even in severe conditions. Opuntioid cacti are very
adaptable, growing in a range of soil types and areas
that receive above 150 mm of rainfall annually.
hen
ry r
Uthe
rfo
rd
Opuntia robusta
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
04 05
The weedOpuntioid cacti are a group of plants that belong to a sub-family of Cactaceae. Originally from the Americas, some species were introduced into Australia to support cochineal dye production, while others were planted as garden ornamentals or hedges.
One of the most well-known opuntioid cacti is
common prickly pear (O. stricta), which covered
some 240 000 km2 before the introduction of the
Cactoblastis moth, a highly successful biological
control agent, in 1926.
There are around 30 species of opuntioid
cacti that have naturalised in Australia, with
infestations in all states and territories except the
Australian Capital Territory and Tasmania.
Plants have jointed stem segments, also known as
pads or cladodes. These segments, which can be
flat or cylindrical, contain the green tissue of the
plant where photosynthesis occurs.
Leaves are small, and typically drop off when
segments are young. Opuntioids often have large,
colourful flowers that are white, yellow, orange,
pink, red or purple. Most produce fleshy fruit which
ripen red, purple or yellow. Some species produce
viable seeds that are bird and animal dispersed.
Varying in form and habit, opuntioid cacti range
from low growing shrubs under 50 cm to erect trees
eight metres tall. They are distinguished from other
Cactaceae sub-families by the presence of glochids
– small, detachable barbed bristles. Glochids grow
from areoles, the small circular or elongated woolly
cushion areas on the surface of segments. Areoles
are also the points from which flowers, new shoots
or spines can grow and are present on both cacti
segments and fruit.
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
hen
ry r
Uthe
rfo
rdhe
nry
rUt
herf
ord
06 07
Opuntia tomentosa
Weed identificationThe appearance of opuntioid cacti
can vary significantly, from the more
familiar tall, erect and flat segmented
common prickly pear (O. stricta),
through to small shrubs with narrow,
flattened, rope-like segments such as
Hudson pear (C. rosea; C. tunicata).
Austrocylindropuntia originate in
South America and are shrubby with
cylindrical to club-shaped segments.
They differ from Cylindropuntia species
in that their spines lack papery sheaths.
Of the 11 species worldwide, two have
naturalised in Australia – A. cylindrica
and A. subulata. These species are
popular in cultivation in other parts of
the world.
Cylindropuntia are native to south
western USA, Mexico and the West
Indies, have cylindrical segments
and spines with papery sheaths that
separate from the spine in their
first year. Many species have easily
detachable segments, such as C.
prolifera, commonly known as jumping
cholla due to its ability to seemingly
‘jump’ onto passing animals, humans
and vehicles.
Opuntia extends from North America
through central America, the West Indies
and Galapagos Islands to Southern
South America. They are branched
shrubs, typically up to two metres high,
though they can grow taller. They have
flattened stem segments, commonly
referred to as pads, which are usually
round or ovalshaped. The most well
known Opuntia species is common
prickly pear, introduced to Australia in
the 19th century.
O.stricta, Prickly pear
A. cylindrica Cane cactus
C. prolifera Jumping cholla
O. robusta Wheel cactus
C. tunicata, Hudson pear
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
08 09
Growth pattern in suitable conditionsOpuntioid cacti are perennial plants that are
generally long-lived. Flowering typically occurs
from spring through to summer, with fruits
forming in late summer and into autumn. Not
all species develop mature fruit, but those that
do can produce numerous seeds, with a hard
seed coat enabling longevity. Seed can germinate
year round depending on rain, though seedlings
are not likely to survive if they are in exposed
conditions. Seedlings can be difficult to detect
when small.
Species identificationUse the following pages as a guide to
help you identify opuntoid cactus.
Key to symbols
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Stem segments
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
flowers
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fruits
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Spines
Glossary
Areole – small circular or elongated woolly cushion
area on the surface of segments.
Glochids – small, detachable barbed bristles.
tubercle – a small raised area or nodule on a plant
surface.
Stem segment – distinct, individual part of the stem.
Can be cylindrical (e.g. in Austrocylindropuntia
& Cylindropuntia), or flattened (e.g. in Opuntia,
commonly referred to as pads).
Sheath – papery outer covering of the spine.
Only present in Cylindropuntia species.
ShAU
nA
Pott
er
Opuntia streptacantha
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
10 11
13Austrocylindropuntia & Cylindropuntia
erect, branching shrub 0.3-1.5m tall. often forms patches several metres wide. deciduous leaves to 1cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
dark bluish-green, shiny. rounded, 15-50cm long, 3-4cm diameter.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
red, cup shaped.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
egg to urn shaped, to 4.5cm long. deep green-yellow green. (Can produce chains).
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
2-6 spines, approx 1cm long. (Lack papery sheath).
Cane cactusAustrocylindropuntia cylindrica
BoB
Chin
no
Ck
Field Identification Guide
12
ShAU
nA
Pott
er
15Austrocylindropuntia & Cylindropuntia
Branching shrub to 3m tall. forms patches to 8m wide. Leaves to 12 cm long and these may persist for more than one season.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Mid green. Slender, to 50cm long, 4-5cm diameter.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pink.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
oblong, egg or club shaped to 10cm long. Green. (Can produce chains).
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
1-4 spines, up to 7cm long. (Lack papery sheath).
Austrocylindropuntia subulata
Field Identification Guide
14
BoB
Chin
no
CkBo
B Ch
inn
oCk
17Austrocylindropuntia & Cylindropuntia
erect shrub up to 0.4-0.8m tall. deciduous leaves. rarely flowers/fruits.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Green-grey green. often distorted, with a corrugated (tuberculate) surface, 10-22cm long, 2-4.5cm diameter. often numerous, easily detached small segments.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
deep red.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
inverse cone or oval shaped. Grey-green. forms long chains. Usually sterile.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
4-15 spines, 7-20cm long (often shorter). Cream to brown (colour variable). (White to tan sheath).
Cylindropuntia fulgida var. mamillata
Coral cactus, boxing glove cactus
Field Identification Guide
16
BoB
Chin
no
CkSh
AUn
A Po
tter
19Austrocylindropuntia & Cylindropuntia
Branched shrub or small tree 1-3m tall. often with short trunks. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
dull grey-green. 15-40cm long, 3.5-5cm diameter. Large, widely spaced tubercles give a woven, rope like appearance.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
dark pink, magenta.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, egg shaped, to 4cm long. Greenish-yellow when ripe. (Can form chains).
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
2-12 spines, 0.8-3cm long. trunks often covered in spines. off white-cream. (off white-cream sheath attached).
Cylindropuntia imbricata devil’s rope/rope pear
Field Identification Guide
18
BoB
Chin
no
CkBo
B Ch
inn
oCk
21Austrocylindropuntia & Cylindropuntia
Cylindropuntia kleiniae
Straggly shrub to 0.5-2.5m tall. Large plants form a trunk. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Light grey-green. 6-26cm long, 0.6-1.2cm diameter.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pink-red.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
egg or cylinder shaped. ripens to orange
.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
1-4 spines, 2-4.5cm long. White to brown. (tan sheath firmly attached).
Field Identification Guide
20
ShAU
nA
Pott
er
ShAU
nA
Pott
er
23Austrocylindropuntia & Cylindropuntia
Cylindropuntia leptocaulis pencil cactus
Spreading shrub 0.4-1.8m tall. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Green-grey green. Very slender, 2-8cm long, 0.3-0.5cm diameter.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pale to greenish yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, egg shaped. yellow to red when ripe. Spineless. often sterile.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
0-4 spines, 0.5-1.5cm long. Cream to pale yellow.
Field Identification Guide
22
ShAU
nA
Pott
erBo
B Ch
inn
oCk
25Austrocylindropuntia & Cylindropuntia
ShAU
nA
Pott
er
BoB
Chin
no
Ck
Low shrub 0.4-1m tall. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Greenish grey. 4-15cm long, 4-5cm diameter. easily detached. Prominent tubercles.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
rose to magenta.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
top shaped, 2-5cm long. Green. Can form chains. Usually sterile .
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
7-11 spines, 1-2cm long. Light to dark brown, interlacing. (White to tan sheath firmly attached ).
Cylindropuntia prolifera Jumping cholla
Field Identification Guide
24
27Austrocylindropuntia & Cylindropuntia
Cylindropuntia spinosior
erect shrub to 1m tall. often forming patches several metres wide. Similar to C. prolifera, but different spine and fruit colour. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Mid grey-green. 10-24cm long, 1.5-3cm diameter. firmly attached. Prominent tubercles.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
rose-purple.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, cylindrical, to 4cm long. yellow, sometimes green.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
6-24 spines, 0.8-1.5cm long, interlacing. White to grey. (White sheath firmly attached).
ShAU
nA
Pott
erBo
B Ch
inn
oCk
Field Identification Guide
26
29Austrocylindropuntia & Cylindropuntia
Low, spreading shrub, 0.5-1m tall. Up to 3m wide. old plants can develop trunks, but not commonly seen. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Grey-pale green. 4.5-26cm long, 1.5-3.5cm diameter. easily detached. Prominent tubercles.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pink-red.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
oblong to egg shaped, to 3cm long. Green-yellow green. Sterile hybrid.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
7-14 spines, 1-4cm long. White to light brown. (White sheath loosely attached).
Cylindropuntia rosea Hudson pear (White-spined)
ShAU
nA
Pott
erBo
B Ch
inn
oCk
Field Identification Guide
28
31Austrocylindropuntia & Cylindropuntia
ShAU
nA
Pott
er
BoB
Chin
no
Ck
Cylindropuntia tunicata Hudson pear (Brown-spined)
Low, densely branched shrub 0.3 to 0.6m tall. deciduous leaves.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pale grey-green. 10-20cm long, 1.5-3cm diameter. easily detached. Prominent tubercles.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellowish-brown.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Club to top shaped. Greenish-yellowish to red. Spineless. Usually sterile.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
4-7 spines, 3-7cm long. red-brown to pale brown. (Brownish sheath loosely attached).
Field Identification Guide
30
33Opuntia
ShAU
nA
Pott
er
Opuntia aurantiaca Tiger pear
Low spreading shrub to 0.3m tall. Branches prostrate to somewhat erect.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
dark green to dark purple. flattened, sometimes rounded, 6-15cm long. easily detached. no tubercles.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow to orange-yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, globular shaped, to 3cm long. red-purple. Sterile.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Usually 2-3 spines, 1-3cm long. Brown-yellowish.
BoB
Chin
no
CkSh
AUn
A Po
tter
Field Identification Guide
32
35Opuntia
ShAU
nA
Pott
er
Opuntia elata Riverina pear
Shrubby plant with erect branches to 2m tall.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Glossy green, sometimes with a purple tinge (especially around areoles and margins). often more than 2cm thick, 5-25cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
orange.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Club shaped, to 6cm long. Purplish red.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Spines absent, or 1-3 short spines present at some areoles. Whitish yellow.
BoB
Chin
no
Ck
Field Identification Guide
34
37Opuntia
keVi
n t
hieL
e
Opuntia elatior
Shrubby, forming dense, much branched clumps 5m tall.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
olive green. oblong shaped, 10-40cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow-orange, with red stripes.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
egg shaped. reddish when ripe.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
2-8 spines, 2-4cm long. needle like. dark brown.
SheP
herd
, r.C
.h.
ww
w.a
nbg.
gov.
au
Field Identification Guide
36
39Opuntia
troy
Bo
WM
AnG
reG
PAt
riCk
Opuntia engelmannii
Low shrub to 1.5m tall. forms dense clumps. Can be confused with O. robusta, but has a low, creeping habit and the pads do not have the milky blue green appearance.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Green. flattened, round to egg shaped, 15-20cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, to 7cm long. Purple. Almost spineless.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
1-6 spines, 1-4cm long. yellowish.
Field Identification Guide
38
41Opuntia
BoB
Chin
no
Ck
Opuntia ficus-indica* Indian fig
Large shrub/tall tree to 5m tall. Usually with a trunk.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
dull blue-green. flattened, egg to oblong shape, 20-60cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
to 10cm long. yellow, orange, red, purple.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Mostly spineless cultivars in Australia.
* Note O. ficus-indica is not a Weed of National Significance and is not a declared weed in all States and Territories.Sh
AUn
A Po
tter
Field Identification Guide
40
43Opuntia
Opuntia microdasys Bunny ears or Golden bristle cactus
Branched shrub, forming thickets to 1m tall.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Green to pale green and velvety. round to oblong shaped, 6-15cm long. distinctive clusters of yellow glochids.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, globular shaped, to 3cm long. red-purple. Sterile.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Spines usually absent, rarely one.
ShAU
nA
Pott
erJU
Lie
deA
n
Field Identification Guide
42
45Opuntia
ShAU
nA
Pott
erSh
AUn
A Po
tter
Opuntia monacantha drooping tree pear
erect shrub to 2m tall, sometimes with a short trunk. Plant has an obvious drooping appearance.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Glossy green. oblong to egg shaped, thin profile, 10-30cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow or orange-yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Pear shaped, to 7cm long. red. Spineless.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
1-2 spines, 2-4cm long. Brown to off-white.
Field Identification Guide
44
47Opuntia
ShAU
nA
Pott
erG
reG
PAt
riCk
Opuntia robusta Wheel cactus
Shrubby /tree-like to 2m tall. Many branches.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Blue green. Circular shape, thick profile, to 40cm wide.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, globular shaped, to 8cm long. deep red. numerous fertile seeds.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
2-12 spines, up to 5cm long. White to pale brown or yellow.
Field Identification Guide
46
49Opuntia
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Opuntia stricta Common prickly pear
Sprawling/ erect shrub, up to 2m tall. forms thickets.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Blue-green. egg or oblong shaped, 10-25cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
yellow.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
fleshy, globular to pear shaped, to 6cm long. Purplish red. numerous fertile seeds.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
in var. stricta spines are absent or the occasional one may be present on a pad but in var. dillenii there are up to 11 spines, 1.5-4 cm long.
Field Identification Guide
48
51Opuntia
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Opuntia tomentosa Velvet pear
Shrubby to treelike, up to 5m tall. often with a trunk. Segments and fruits covered in fine hairs, giving a velvety appearance.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
oblong to egg shaped, 15-30cm long.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
orange.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
Globular to egg shaped, to 5cm long. red.
Spines
Fruits
Flowers
Stem Segments
Spines
Fruits
Flowers
Stem Segments
often spineless, but can have 0-4 spines, 0.5-1.5cm long. Whitish-yellow.
Field Identification Guide
50
How they spreadVegetative spread is the most common form
of dispersal, and can occur year round when
segments, immature fruit or flowers detach and
make ground contact. New shoots then grow
from areoles on the upper surface of the segment.
Segments of many opuntioids will attach easily
to clothing, footwear and the fur and limbs of
animals, aiding their spread. New growth (and
spread) can also occur from flowers, from which
new shoots or roots can grow.
Seeds are a less common form of spread as not all
opuntioid cacti produce viable seed. Species such
as wheel cactus (O. robusta) and common prickly
pear (O. stricta) produce bright, large fruit that are
attractive to birds, aiding dispersal. Other animals,
such as foxes, also spread the seed.
The spread of cacti is aided by the movement
of water; hence distribution often occurs along
watercourses, drainage lines and across flood
plains.
Where they growOpuntioid cacti grow throughout a wide climatic
range, from arid, semiarid environments to warm
temperate, sub-tropical and tropical areas.
In Australia they appear to have no preference for
soil types and are found growing in calcareous loam,
shallow granite, red earths and clay soils. Cacti flourish
around old homesteads, dumps and mine sites.
What to do about themWhile there are several options for managing
opuntioid cacti, the most appropriate method will
depend on the size and age of the infestation, site
access, resources and the species being managed.
For large infestations, integrated weed management
approaches will be necessary, using a combination
of biological control (if available), herbicides and or/
manual removal. Follow-up is essential in any control
program, particularly given the ability of cacti to
reproduce from segments or fruit.
Spread preventionOpuntioid cacti are spread from the movement of
seeds, fruit and segments via birds, animals, water,
vehicles, equipment and people. Good hygiene is
essential when working in infested areas, including
staying on tracks. All segments and fruits should
be removed from an area as they are capable of
regrowing, even under very harsh conditions.
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
52 53
Chemical controlThe Australian Pesticides and Veterinary Medicines
Authority (APVMA) regulates the use of chemicals
in Australia. For more details on herbicide
registration and permits visit the APVMA website,
www.apvma.gov.au.
Registration of herbicides varies across states and
territories. You should always check the product
label and seek advice from your local council or
state/territory weed management agency for
information on spray rates and adjuvants.
Opuntia species respond well to stem/ pad
injection, while many Cylindropuntia species
require overall spraying. When using herbicides,
care must be taken to ensure adequate coverage
of the plant (all sides of the segments) to prevent
regrowth. In the case of foliar spraying, the addition
of a marker dye will assist with identifying any missed
plants or segments.
Plants should be actively growing and not under stress
from heat/drought or cold conditions. Plants may
die quicker as a result of warm weather spraying, as
cooler conditions can slow the uptake of herbicides.
Herbicides may not result in a complete kill.
Control sites should therefore be monitored for
regrowth and follow-up activities applied if necessary.
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Cylindropuntia prolifera
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
54 55
FireHot fires can kill plants, although regrowth may
occur. Burning can also assist in providing access
to sites so that other control activities can take
place. Removing the bulk of the plant through
burning can also reduce the amount of herbicide
required for follow up control. Advice should be
sought and permission may be required in areas
of native vegetation. Check with your local council
or state/ territory weed management agency.
GrazingThe spines on opuntioid cacti prevent grazing in
most instances, however, stock and other animals
sometimes feed on less spiny species in times of
drought. In most instances the presence of opuntioid
cacti limits or prevents grazing activities.
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Cylindropuntia imbricata
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
56 57
Mechanical controlCare must be taken when mechanically or
physically removing opuntioid cacti due to their
spiny nature. Small, isolated plants are easier to
remove than large, dense infestations and some
species, such as Hudson pear and devil’s rope,
can pose significant risk of injury when handled.
Physical removal can be difficult as any segments
detached in the process can regrow to form new
plants. Material must be disposed of appropriately
via deep burial.
Biological controlThere are two main agents used in the biological
control of opuntioid cacti – Cactoblastis cactorum,
a moth with stem boring larvae, and several
Dactylopius species, cochineal scale insects.
Cactoblastis has been extremely successful in
controlling common prickly pear (O. stricta)
in most situations, although it is less effective
in cooler, wetter areas or very dry locations.
Cactoblastis larvae feed on segments, resulting
in the collapse of plants. They can feed on a
range of opuntioid cacti, but are only effective at
controlling common prickly pear.
There are several Dactylopius species (cochineal)
present in Australia. The species look similar to the
naked eye so it is important to use the correct
cochineal. For example, cochineal that is effective
on tiger pear will not work on common prickly
pear. Heavy rain and cold weather can inhibit
the effectiveness of cochineal. However, successful
control is possible for tiger pear, common prickly pear,
drooping tree pear, devil’s rope and velvety tree pear.
It is relatively easy to infect vulnerable cacti species
with Cactoblastis and cochineal by re-distributing the
agents either as eggs (in the case of Cactoblastis) or
by placing infected segments on unaffected plants
(in the case of Cactoblastis larvae or cochineal).
Researchers are investigating potential cochineal
strains for the control of Hudson pear and trials are
underway for the use of cochineal on wheel cactus.
hen
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Uthe
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Opuntia robusta
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
58 59
LegislationOpuntioid cacti are declared weeds in Australia.
Opuntia ficus-indica (Indian or Barbaryfig) is
generally excluded from declaration (except in
Western Australia) as it is a commercial food crop
in parts of Australia.
Weed control contactsACt dePt of the enVironMent, CLiMAte ChAnGe, enerGy And WAter13 22 [email protected]/environment
nSW dePt of PriMAry indUStrieS 1800 680 [email protected]/agriculture/pests-weeds/weeds
nt dePt of LAnd reSoUrCe MAnAGeMent08 8999 [email protected]/weeds
QLd BioSeCUrity QUeenSLAnd, dePt of eMPLoyMent, eConoMiC deVeLoPMent And innoVAtion13 25 [email protected]
SA BioSeCUrity SA, dePt of PriMAry indUStrieS And reGionS SA08 8303 [email protected]/biosecuritysa/nrm_biosecurity/weeds
tAS dePt of PriMAry indUStrieS, PArkS, WAter And enVironMent1300 368 550Go to www.dpipwe.tas.gov.au/weeds , scroll to the bottom of the page and click on “weedsenquiries”www.dpipwe.tas.gov.au/weeds
ViC dePt of PriMAry indUStrieS13 61 [email protected]/agriculture/pests-diseases-and-weeds
WA dePt of AGriCULtUre And food 08 9368 [email protected]
AUStrALiA WideAUStrALiAn PeStiCideS And VeterinAry MediCineS AUthority02 6210 4701 [email protected]
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Opuntia tomentosa
Field Identification Guide
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ACKnoWLedGeMenTS
Compiled by Shauna Potter and Henry Rutherford, Biosecurity SA, April 2013.
Key ReFeRenCeS
Chuk, M. (2010) Invasive cacti – a threat to the rangeland of Australia. Proceedings of the 16th Biennial Conference of the Australian Rangeland Society, Burke (Eds D.J. Eldridge and C. Waters)
Edmunds, L.J. (2006) A community approach to pest plant control in South Australia’s rangelands. . In C. Preston, J.H. Watts and N.D. Crossman (eds). Proceedings of the 15th Australian Weeds Conference. Weed Management Society of South Australia, Adelaide, pp. 203-206.
Harvey, A. (2009) Draft state opuntioid cacti management plan (2009). Primary Industries and Regions South Australia.
Holtkamp, R.H. (2006) Hudson pear. Primefact 240. NSW DPI.
Hosking, J.R., McFadyen, R.E., Murray, N.D. (1988). Distribution and biological control of cactus species in eastern Australia. Plant Protection Quarterly 3(3): 115-123.
Johnson, S.B., Hosking, J.R., Chinnock, R.J. and Holtkamp, R.H. (2009) The biology of Australian weeds 53. Cylindropuntia rosea (DC.) Backeb. and Cylindropuntia tunicata (Lehm.) F.M. Knuth. Plant Protection Quarterly 24 (2), 42- 49.
Parsons, W.T. and Cuthbertson, E.G. (2001). Noxious Weeds of Australia (2nd ed.) CSIRO Publishing, Collingwood.
Prickly pear (Opuntia, Nopalea and Acanthocereus spp.) fact sheet (2009). Queensland Government
InFoRMATIon And GuIde ReVISIon
Julie Dean, David Cooke, Adrian Harvey & Kenn Pearce (PIRSA); Mike Chuk, (DCQ); Royce Holtkamp, John Hosking and Stephen Johnson (DPI NSW); Bill Palmer (DAFF QLD); Bob Chinnock; Ruth Myers (DPI Vic); Kym Haebich (SA MDB NRM Board); Karen Stewart (DPIPWE).
Cylindropuntia fulgida var. mamillata
Field Identification Guide
Austrocylindropuntia, Cylindropuntia and Opuntia species
62 63
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