Leptospermum petersonii F.M.Bailey

lemon-scented tea tree

Australia: coastal eastern Australia from Queensland to Port Macquarie district of New South Wales.

In New Zealand mostly occurs as a cultivated tree; some seedlings are recorded beneath and near parent plants.

Scattered records from mainly urban areas in the North Island, particularly Auckland, also from the northern South Island of New Zealand.

• Leaves lemon-scented.
• Leaves with tips blunt and notched.
• Leaves narrowly lanceolate to elliptic.
• Each leaf base with a flange extending down the stem.
• Sepals deciduous.
• Sepal hairy near the tip.
• Stamens in bundles.
• Fruit valves slightly woody.

Shrub or small tree to about 5 m tall.

Older stems with persistent fibrous bark. Young branchlets and stems hairy, soon becoming hairless. Each leaf base with a pale, wide flange that extends down the stem.

Adult leaves alternate, lemon-scented, narrowly lanceolate to elliptic, usually 20–40 mm long, 2–5 mm wide, same colour on upper and lower surface, leaf blade flat, margins often recurved, leaf surfaces not puckered, hairy at first, but becoming hairless, margins entire, tips blunt, notched, leaf stalks absent.

Flowers solitary, axillary, ± 10–15 mm in diam., stalk ± 1 mm, petals 5, ± 5–6 mm long, white; flower base (hypanthium) with obvious oil glands, sepals 5, tips free, hemispherical, margins sometimes hairy, deciduous; stamens 2.5–3.5 mm long, white, in bundles. Main flowering period: summer, but some flowers may be present in autumn.

Fruit dry, 5-locular, ± 6 mm wide, somewhat persistent, surface flaking, becoming woody with age; valves woody, raised, spreading as wide as the rim; lower part of fruit below the rim shallow.

In New Zealand, green-leaved L. morrisonii is similar to L. petersonii, but the former possesses acute leaf tips and stamens 3.5 mm or longer while the latter possesses notched leaf tips and stamens 3.5 mm or shorter.

Two subspecies of L. petersonii are sometimes referred to. However, according to the Australian Plant Census (APC), L. petersonii subsp. petersonii (often with lemon-scented leaves) = L. petersonii, and L. petersonii subsp. lanceolatum (without a distinct lemon odour) of Northern Australia and Malesia = L. amboinense, as reinstated by Bean (1992). That assessment is followed here.

Leptospermum petersonii subsp. petersonii is widely cultivated, and it is unlikely that cultivated specimens display the whole variation found within the subspecies. Collections have been made in New South Wales which lack the distinctive lemon scent and leaf apex which diagnoses L. petersonii. Based on the leaf apex, it appears that only the former subspecies, L. petersonii subsp. petersonii, occurs in New Zealand.

Leptospermum is a genus of about 87 species, mostly Australian, but extending to Malesia and New Zealand.

• Flora of New Zealand Online
• GBIF
• iNaturalist NZ
• NZPCN
• PlantNET: New South Wales Flora Online
• Plants of South Eastern New South Wales
• VicFlora: Flora of Victoria
• Weeds of Australia: Biosecurity Queensland