''Acronychia acidula'', commonly known as lemon aspen or lemon wood, is a species of small to medium-sized rainforest tree that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to Queensland. It has simple, elliptical leaves, small groups of flowers in leaf

axil A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

s and more or less spherical fruit. The aromatic and acidic fruit is harvested as a

bushfood Bush tucker, also called bush food, is any food native to Australia and historically eaten by Indigenous Australians and Torres Strait Islander peoples, but it can also describe any native flora, fauna, or fungi used for culinary or medicinal ...

Description

''Acronychia acidula'' is a tree that typically grows to a height of about . It has simple, elliptical,

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

leaves that are long and wide on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

long. The crushed leaves often have an odour resembling that of mango (''

Mangifera indica ''Mangifera indica'', commonly known as mango, is an evergreen species of flowering plant in the family Anacardiaceae. It is a large fruit tree, capable of growing to a height and width of . There are two distinct genetic populations in modern m ...

''). The flowers are arranged in groups long, in leaf axils or between the leaves, each flower on a glabrous

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

long. The four

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s are long and the four

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s long. The eight

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

alternate in length. The fruit is a fleshy, more or less spherical

drupe In botany, a drupe (or stone fruit) is a type of fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pip'' (UK), ''pit'' (US), ''stone'', or ''pyrena'') of hardened endocarp with a seed ...

long and the seeds are about long.

Taxonomy

''Acronychia acidula'' was first formally described in 1864 by Victorian state botanist

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Victoria, Australia ...

in ''

Fragmenta phytographiae Australiae ''Fragmenta phytographiae Australiae'' is a series of papers written by the Victorian Government botanist Ferdinand von Mueller in which he published many of his approximately 2000 descriptions of new taxa of Australian plants. Including the p ...

'' from specimens collected by

John Dallachy John Dallachy (c. 1808 – 4 June 1871) was a curator of Melbourne Botanic Gardens and a plant collector. Dallachy was born in Elginshire, Scotland. He worked as a gardener for the Earl of Aberdeen and Kew Gardens. In 1847, he went to Ceylon t ...

in the

Seaview Range The Seaview Range, part of the Great Dividing Range, is a mountain range located west of Ingham in North Queensland, Australia. Much of the range is covered by rainforest and parts of it are protected in the Girringun National Park and the We ...

near

Rockingham Bay Rockingham Bay is a bay in Far North Queensland, Australia. The bay opens onto the Coral Sea, part of the South Pacific Ocean. Adjacent to the bay is the Girramay National Park, south of which is the town of Cardwell. Goold Island is a small ...

. Its species name ''acidula'' is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for 'slightly acid'.

Distribution and habitat

Lemon aspen grows in rainforest at altitudes of up to from the

Atherton Tableland The Atherton Tableland is a fertile plateau, which is part of the Great Dividing Range in Queensland, Australia. It has very deep, rich basaltic soils and the main industry is agriculture. The principal river flowing across the plateau is the B ...

to the Eungella Range in Queensland.

Ecology

The fruit are eaten by the

topknot pigeon The topknot pigeon (''Lopholaimus antarcticus'') is a pigeon native to eastern Australia. Taxonomy English naturalist George Shaw described the topknot pigeon as ''Columba antarctica'' in 1793. The topknot pigeon is sister taxon to a lineage t ...

(''Lopholaimus antarcticus'').

Uses

Lemon aspen fruit has a grapefruit and lime-like flavor, and is popular in beverages, sauces and confectionery. The fruit has high

antioxidant Antioxidants are Chemical compound, compounds that inhibit Redox, oxidation, a chemical reaction that can produce Radical (chemistry), free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants ...

activity.

Cultivation

The tree is grown in small-scale commercial bushfood orchards on the east coast of Australia from North Queensland to northern

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

. The tree is quick-growing and requires regular pruning to maintain a practical harvesting height. It has a moderate crop yield, and bears in four years from seedlings. It prefers well-drained and fertile clay loam soils, with a sunny aspect and extra moisture when young.

Cultural references

Lemon aspen featured on an Australian postage stamp in 2019.

References

{{Taxonbar, from=Q2468799 acidula Flora of Queensland Trees of Australia Plants described in 1864 Taxa named by Ferdinand von Mueller