Quick Facts

Quick facts

• Originally from the Middle-east, Azzarola (Crataegus x sinaica) is a thorny, upright shrub or small tree with white flowers 1.5 cm across and red globular fruits to 2.5 cm across.
• Propagates mainly by seed contained within the red fleshy fruits that are eaten and mainly spread by birds.
• Due to its cultivation as an ornamental or hedge plant it has spread into natural areas and can dominate and exclude native plants and animals.
• Occurring in temperate coastal / sub-coastal to higher rainfall inland areas like the Adelaide Hills.
• It is not widely established, and only occurs with any frequency in suburban areas near Adelaide and the Hills and Melbourne.
• The specific environmental and agricultural impacts of Azzarola are not fully understood, but it would likely have similar impacts to Hawthorn (Crataegus monogyna).
• Can be controlled by mechanical means and herbicides normally applied to cut stems.

What Does It Look Like?

What is it?

Azzarola (Crataegus x sinaica) [as Crataegus sinaica] is a large deciduous shrub or small tree, usually 2–6 m in height, but growing up to 10 m. The bark is generally smooth when young, but becomes rough towards the base of the stems and branches in older plants. The stems are erect and spreading and sometimes armed with a few thorns 0.5 to 2.5 cm long, twigs covered with short woolly hairs to few hairs, very occasionally older twig are pruinose (covered with a waxy material). Leaves are alternate arranged, with two different types of shoots present, flowering and vegetative shoots. Leaves produced on the old woody short and flowering shoots are up to 6 cm long. Leaves produced on vegetative shoots are generally larger to 7.5 cm long, with petiole leaf stalk 1–2.5 cm long. All leaves are wedge shaped, have 3 sometimes or rarely 5 [mostly] forward pointing lobes, and can be distinctly toothed, particularly at the tips. Leaves above are deep-fresh green with a few long hair to no hairs, leaves below are lighter green have long hairs along major veins, and in the axis of main and secondary veins, w Leaf-like appendages often occur at the base of the leaves but are soon lost only seen when the leaves are produced in spring.

Flowers are borne in small clusters on short pedicels (flowers stalks) that are slightly hairy. Flowers are about 15 mm across, white or cream or pink, with 5 outer triangular green sepals 1.5–4 mm long, and 5 petals 4–8 mm long. The flowers have 20 stamens with pale pink red anthers before bursting open releasing pale yellow pollen. There are usually 2 (rarely one) stigmas that are club shaped. 

Fruits are fleshy, firm, globular 'berries' are orange-red to red to deep red when ripe, and are 1–2.5 cm in diameter. These 'berries' are and enclose 2–3 hard brown seeds (Symon 1986; Parsons & Cuthbertson 2001; Navie 2004). 

For further information and assistance with identification of Azzarola contact the herbarium in your state or territory.

Flower colour

White, Pink

Growth form (weed type/habit)

Tree, Shrub

Where it currently grows? Preferred habitat

Azzarola invades a broad range of vegetation communities including riparian and coastal and sub-coastal temperate regions. It infests old gardens, disturbed sites and degraded native habitats, predominantly near populated areas (Navie 2004; Government of South Australia 2021).

Are there similar species?

Azzarola (Crataegus x sinaica) is a spiny plant with relatively large, reddish-coloured, fruit (10-25 mm across) that contain two or three hard 'seeds' (i.e. pyrenes). Its young stems are covered in soft hairs (i.e. they are pubescent).

It is also similar to azarole (Crataegus azarolus) a spineless plant with similar sized  yellow-orange ripe fruit (up to 20 mm across) that usually contain two or three hard 'seeds' (i.e. pyrenes).

Azzarola is similar to Hawthorn (C. monogyna), but the latter species has relatively small fruit (5–12 mm across), only 1 seed per fruit (as opposed to 2–3 seeds per fruit in Azzarola), and young stems that are generally hairless (glabrous) (Navie 2004).

Azzarola is similar to the Cotoneasters (Cotoneaster species), but these species have leaves with entire margins, and do not have spines (Symon 1986). Azzarola is also similar to the Firethorns (Pyracantha species). However, Firethorns have leaves with entire or finely toothed margins, and are not lobed (Navie 2004).

Why Is It A Weed?

What are its impacts?

Azzarola has similar environmental and agricultural impacts to the closely related species Hawthorn (Crataegus monogyna) such as invading native and agricultural lands, restricting stock movement and providing harbour for pest animals (Parsons & Cuthbertson 2001). It forms dense thickets that can impede movement of stock and humans. 

Native ecosystems: Azzarola can spread away from plantings during favorable conditions into native grasslands, woodlands, forest areas, and poorly managed pastures. These dense patches can also provide cover for pest animals such as rabbits (Parsons & Cuthbertson 2001). Azarola can have a major impact on bushland habitats, shading out ground-flora and affecting the growth and regeneration of overstorey plants. It is likely that the leaves dropped each autumn impact on biodiversity by increasing nutrients levels in surface soil. Dense patches compete with native regrowth and form spiny thickets that provide good cover for rabbits and other pests (Government of South Australia 2021). In the Adelaide Foothills, Azzarola together with introduced Olives have invaded many hectares across a hillside at Mount Osmond Reserve, between Waterfall Gully road and the Lookout with little to no native vegetation remaining. 

Agriculture: It can form dense stands that reduce grazing capacity of stock due to exclusion and as the spines act as a deterrent. Due to the presence of hydrocyanic acid in some Crataegus species, Hawthorn is potentially hazardous to grazing stock (Parsons & Cuthbertson 2001). In the British Isles, Crataegus species are an important reservoir of the fire blight bacterium which affects pears and apples. Azzarola also is known to host Mediterranean fruit fly and light brown apple moth (Government of South Australia 2021).

It is assumed that this could have similar or worse impacts as Hawthorn (Crataegus monogyna). Please see that profile for more details.  

How does it spread?

Azarola reproduces by seed and suckers.They produce large amounts of seed in the edible fruit (haws),  which are dispersed to new areas by birds and mammals (foxes, possums and wallaroos), which eat the fruit.  Seeds can also be dispersed by water. Over 2,000 fruits with 2–3 seeds each would be produced on a mature tree. Seed can take 2 or more years to germinate as it is enclosed in a hard pit. The fruit can contaminate farm machinery, vehicles, agricultural produce, and garden waste, but these vectors are thought to be of little significance for its spread. Much of the initial spread in the past was by deliberate plantings, but this has ceased (Parsons & Cuthbertson 2001; Navie 2004; (Government of South Australia 2021).

What is its history in Australia?

The time of introduction of Azzarola into Australia is not known, but it was probably introduced as an ornamental, and is naturalised near Adelaide (South Australia) and Melbourne (Victoria).

How To Manage It?

Best practice management

Non-chemical control: Hawthorn seedlings can be controlled by pulling or grubbing (Robertson 2006). Larger plants can also be removed mechanically, but regrowth can occur unless the entire crown and the top few centimetres of root are removed (Parsons & Cuthbertson 2001) so chemical treatment helps  kill plants.

Chemical control: The trunks of large plants can be drilled and filled with herbicide, or can be cut near the ground and the base painted or swabbed with herbicide. Overall spraying of Hawthorn plants is not reliable (Parsons & Cuthbertson 2001; Robertson 2006), but small plants and seedlings are susceptible to spot spraying.

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au 

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Azzarola germinates in autumn. It has slow early growth with its competitive ability low at the seedling stage but high once the bushes are established.  Early growth is slow, and plants do not flower until the second or third year. Flowers are produced mainly in spring, but sometimes into early summer. Fruit ripen in summer and the leaves are shed as temperatures fall in autumn. New growth is then produced the following spring. Azzarola is a long lived plant, and can potentially live for more than 70 years (Parsons & Cuthbertson 2001; Navie 2004).

Where Is It Found?

Which states and territories is it found?

VIC, SA

What areas within states and territories is it found?

Azzarola is not widely naturalised in Australia, and is found mostly near populated areas, particularly on Mt. Lofty and the Adelaide foothills in South Australia, in suburban Melbourne in Victoria and the ACT (Symon 1986; Navie 2004; Richardson et al. 2006).

Where does it originate?

Azzarola is native to the Middle East (Symon 1986).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

SA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Crataegus x sinaica

Other scientific names (synonyms)?

Crataegus azarolis var. sinaica (Boiss.) Lange

Does it have other known common name(s)?

Azarola, Azzarola Hawthorn, Azzarola Thorn May, Neapolitan Medlar, Whitethorn, Mount Sinai Thorn