Finger lime

Story and photos by Russ Grayson

Finger lime is a tasty and citrusy small tree for the home and community garden as well as for the commercial orchard.

Common name: Finger lime

Botanic name: Citrus australasica (previously Microcitrus australasica)

Family: Rutaceae

Growth form:

medium to large shrub or small tree of four to five metres in height and three to four metres spread
green fruit 30–120mm long filled with tiny pink or cream beads of juice
white flowers 10 to 14mm diameter
perennial
small, thick leaves
spines along branches.

Centre of diversity: Australia.

Natural habitat: subtropical lowland rainforest understorey of SE Queensland and Northern NSW growing in a variety of soils.

Useful part: the green-yellow fruit.

Uses:

food, edible raw — fresh, juicy vesicles give the sensation of a burst of tangy flavour when chewed
make into garnish, jams
grown commercially following emergence of gourmet bushfood market.

Ethnobotanical uses:

used by Aboriginal people
named ‘Gulalung’ in the Bundjalung language of Northern NSW, its centre of diversity.

Reproduction:

from seed or cutting
seedlings are reported to take a minimum of five years to reach maturity
commercially available grafted onto citrus rootstock and cross-bred with other citrus species
hybrid cultivars produce fruit in a variety of colors
does not appear to attract fruit fly
may require pest management measures in cultivation.

Cultivation:

grows from tropical to temperate climates
prefer soil around pH6
slow growing
grows in full sun or dappled shade
well-drained soils
reported to tolerate light frost but young plants require frost protection
susceptible to the usual range of citrus pests and diseases including citrus gall wasp (Bruchophagus fellis) that can reduce yield and vigour.

Uses in landscaping:

growth form makes finger lime suitable for planting in home gardens and in smaller community gardens
plant as a food source
plant as a component of mixed orchard
understory to taller trees in multi-level orchard or food forest
plant as component of Australian bushfood botanical collection
in cooler climates, plant on northward-facing (sunward) site.

Notes: The finger limes in the photo are growing near Bellingen in subtropical northern NSW.

PHOTO: Russ Grayson (www.pacific-edge.info).