Clausena lansium

Clausena lansium
Scientific name	Clausena lansium
Common names	wampi, wampee, huangpi, Chinese wampee
Genus	Clausena
Family	Rutaceae
Order	Sapindales
Fruit type	Berry
Growth form	Small evergreen tree or shrub
Native range	Northeastern Bangladesh through southern China and mainland Southeast Asia
Climate and site	Warm humid tropical to subtropical; wet-tropical biome
Mature size	About 6 m in cultivation; larger specimens are reported
Propagation	Fresh seed; grafting onto Citrus rootstocks is documented
Years to fruit	N/A; highly dependent on seedling versus Citrus-grafted material

Wampi is a small evergreen Rutaceae tree cultivated in southern China and Southeast Asia for its clusters of pale yellow to brownish, aromatic fruit. The accepted name is *Clausena lansium* (Lour.) Skeels; *Clausena wampi* and *Quinaria lansium* occur as synonyms. The fruit is often sold under several spellings of wampi or wampee, so the scientific name is the useful identity anchor.^[1]

Description

Mature yellowish wampi fruits on the tree. Photo by Forstbirdo, CC BY 3.0, via Wikimedia Commons.

The tree is usually small in cultivation, with pinnate foliage and many-flowered terminal panicles. Fruits are ovoid to subglobose berries, roughly pigeon-egg-sized in the Riverside collection, and may be white or yellow depending on the type. UCR describes sour, subacid, and sweet horticultural forms.^[2]

Distribution and habitat

Kew places the species' native range from northeastern Bangladesh through southern China and Indo-China and assigns it to the wet tropical biome. A grower should read that broad range as evidence for warm, moisture-available conditions, not as proof of one universal soil texture or irrigation schedule.[1]

Cultivation

Use fertile, organic, moisture-retentive soil that still drains freely after rain. A precise species-specific pH or watering interval was not established in the sources reviewed, so those values should not be treated as fixed requirements. Bright light to full sun is appropriate for established trees, with shelter and gradual acclimation for young plants. Warm humid air resembles the native setting, but good airflow is still useful in dense plantings.

Soil and water

The wet-tropical distribution supports even moisture during active growth, while the tree's cultivation as a fruit crop argues against permanently stagnant soil. Treat the recommendation for moisture-retentive, aerated soil as a cultivation interpretation rather than a measured native-soil requirement.

Sun and humidity

Provide bright light or full sun after acclimation. Young plants may need temporary protection from harsh exposure. No defensible relative-humidity percentage was located; avoid presenting one as species-specific.

Seasonal changes

At Riverside, the accession flowered from February through June and ripened from July through September. Those dates describe that climate and accession, not a universal calendar. The sources reviewed do not establish a dependable dormant period or predictable leaf drop, so irrigation and cold protection should be adjusted to local conditions rather than to an assumed dormancy.[2]

Propagation

Fresh seed is a documented method. The UC Riverside accession was received as seed, and seed should be sown promptly rather than allowed to dry for long periods. UCR also records wampi grafted onto Citrus rootstocks; that combination can be induced into earlier flowering and fruiting. A general years-to-first-fruit figure is not reliable enough to give: rootstock and propagation method materially affect the result.[2]

Flowering, fruiting, and harvest

Unripe wampi fruits on the tree. Photo by Earth100, CC BY 3.0, via Wikimedia Commons.

Flowers are borne in many-flowered terminal panicles. In the Riverside collection, flowering ran from February to June and ripening from July to September. Harvest should follow the cultivar's mature color and flavor rather than a universal date; the reviewed sources did not provide one dependable firmness index.[2]

Fruit and uses

The pulp is eaten fresh. UCR describes sour, subacid, and sweet forms and compares the texture with a loquat. The seeds are not ordinary edible pulp. Experimental research has identified the neurotoxic compound lansamide I in wampi fruit, especially seeds; the human dietary risk and safe thresholds remain unresolved, so seeds should not be eaten casually or used medicinally.^[3]

Photos

References

• ↑ [1] Kew, Plants of the World Online: Clausena lansium.

• ↑ [2] UC Riverside Givaudan Citrus Variety Collection: Wampee.

• ↑ [3] Chen et al. 2023, Food and Chemical Toxicology: lansamide I in Clausena lansium fruit.

Image credits

• Clausena lansium.jpg — WingkLEE, public domain (PD-self).
• Clausena-lansium-Hong-Kong-1.JPG — Forstbirdo, CC BY 3.0.
• Clausena lansium unripe fruits.JPG — Earth100, CC BY 3.0.