Backhousia citriodora F.Muell.

lemon ironwood, lemon myrtle, lemon-scented myrtle

Australia: coastal rainforest areas in Queensland and New South Wales.

In New Zealand only found in cultivation; no naturalised specimens recorded.

Scattered records from mainly urban areas in the upper half of the North Island of New Zealand.

• Leaves lemon-scented when crushed.
• Leaf margins scalloped.
• Leaves feather-veined.
• Two sepals smaller than the rest.
• Ovary 2-locular.

Upright trees or shrubs, to 6 m tall.

Bark grey, smooth throughout. Branchlets with hairs.

Adult leaves opposite, ovate, 50–100(–120) mm long, 18–35 mm wide, different colour on upper and lower surfaces; leaf blade flat, hairy when young, but becoming hairless with age, feather-veined, leaf surfaces not puckered; margins scalloped; tips pointed, leaf stalks 10 mm or more long.

Flowers produced in terminal clusters, flowers ± 5–7 mm in diam., flower stalks long; petals 5, rounded, yellow-green to cream; sepals 5, two smaller than the rest, tips free, persistent, hairy and covered in glandular dots; many stamens, white, longer than petals and sepals. Main flowering period: summer to early autumn.

Fruit dry, 2-locular, containing several small seeds.

The upright habit, light green, lemon-scented foliage, and rounded clusters of pale yellow-green flowers with persistent sepals are distinctive. Pittosporum eugenioides, lemonwood, has a similar upright habit and light green leaves that are lemon- or resin-scented, and rounded clusters of pale yellow flowers, but the contrasting pale green central leaf vein, undulate leaf margins, shorter flower stalks, narrow-petalled flowers with only 5 stamens, and sticky seeds clearly distinguish it from B. citriodora.

Backhousia is a genus of 13 or more species endemic to Australia.

• Australia’s Flora: Growing Native Plants
• Australian Tropical Rainforest Plants
• CitSciHub
• GBIF
• iNaturalist NZ