1 / 11

Flindersia australis

crows ash

Rutaceae Eastern Australia

Attracts Pollinators

SunFull Sun – Part Shade

WaterMedium

HardinessZones 10–11

Overview

Flindersia australis is an evergreen to briefly deciduous tree growing 50-130 feet (15-40 m) tall in rainforest, and commonly 30-50 feet (9-15 m) in open or cultivated settings, with a straight trunk and a dense, rounded crown. The leaves are pinnate, 6-12 inches (15-30 cm) long, with several glossy, lance-shaped leaflets 2-5 inches (5-13 cm) long that have oil dots visible against the light. Branched panicles of small white to cream flowers open in spring. The fruit is a woody capsule 2-4 inches (5-10 cm) long, covered in short spines, that splits into five segments to release winged seeds. The trunk bears scaly bark that sheds in patches, leaving a mottled surface. The tree grows in dry rainforest, riverine forest, and rainforest margins on fertile soils, and is sensitive to hard frost when young.

Native Range

Native to eastern Australia, from north-eastern Queensland through to north-eastern New South Wales. Grows in dry rainforest, riverine and gallery forest, and rainforest margins on fertile, well-drained soils, from the lowlands to lower slopes.

Suggested Uses

Planted as a shade and street tree in warm-climate parks and large gardens, spaced 25-40 feet (8-12 m) from buildings and other trees. Used in rainforest regeneration and for timber in plantations. The mature size and spiny fallen capsules make it better suited to large spaces than small gardens or paved areas.

How to Identify

Recognized by pinnate, glossy leaves 6-12 inches (15-30 cm) long with oil dots in the leaflets, and scaly bark that sheds to leave a mottled trunk. The woody, spiny capsule 2-4 inches (5-10 cm) long splitting into five segments sets it apart from co-occurring rainforest trees. Crushed leaves carry the oil-gland scent typical of the family.

Appearance

Size & Dimensions

Height50' - 130'

Width/Spread30' - 50'

Reaches mature size in approximately 20 years

Colors

Flower Colors

white

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~4 weeks

Spring

Flowers in spring, from about September to November in eastern Australia. Panicles of small white to cream flowers open over several weeks. Woody spiny capsules develop over summer and can persist on the tree after releasing their seeds.

Detailed Descriptions

Flower Description

White to cream

Foliage Description

Glossy green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 5-9 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam clay

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

15-25 years

Care & Maintenance

Care Guide

Grows in full sun to part shade in deep, fertile, well-drained soils in warm climates. Water young trees through dry spells until established; mature trees tolerate short dry periods but grow more strongly with deep soil and steady moisture. Hard frost can damage young growth, limiting the tree to warm-temperate and subtropical areas. Falling leaves, bark, and spiny capsules create litter beneath the canopy. The timber is hard and was widely logged, so large old trees are uncommon in some areas. Few pests cause serious damage in cultivation.

Pruning

Prune young trees in late winter to develop a single straight trunk and remove low or crossing branches. Mature trees need little pruning beyond removing dead or damaged wood. Removing large limbs can allow decay into the trunk.