Sapindaceae
How to identify a longan tree
Dimocarpus longan · also called dragon eye, lengkeng (Indonesian/Malay), nhãn (Vietnamese), ลำไย / lamyai (Thai)
Small brown-skinned fruit with translucent, musky-sweet flesh around a dark seed. More heat- and drought-tolerant and reliable-bearing than its lychee relative; Thai growers commonly induce off-season crops with potassium chlorate.
Field marks
These features are typical of the genus Dimocarpus, so they help confirm you are looking at the right group; the fruit and the details below separate the species.
- Leaves are pinnately compound with several pairs of leaflets.
- Fruit hangs in clusters and is small and round, with a smooth, thin, tan to light-brown shell around translucent white flesh.
Check a photo
Photograph one whole, mature leaf from above, or a flower or fruit, and the identifier will return ranked matches. If longan is the top result, the field marks above are your second opinion.
Leaves, flowers, fruit, or bark — closer and sharper identifies better. Your photo is identified and discarded, never stored.
Where and when you will find it
- Origin / cultivation history
- Southern China and Southeast Asia
- USDA zones
- 9b-11
- Climate
- Subtropical to tropical, more cold-tolerant than lychee, can handle brief light chill.
- Fruiting season
- July, August and September (typical, Northern Hemisphere)
- How often grown
- Widely grown
Fruit is the most reliable way to confirm an identification, so July, August and September is the easiest window. Outside it, rely on the leaves and the overall habit. A tree growing well outside the climate above is more likely to be a look-alike.
Growing it: seedling or grafted?
A young tree with no fruit is harder to identify and easy to mislabel, so it helps to know how long it takes to reach fruiting age and how it is usually propagated.
- Years to first fruit
- Seedling 4-6 yrs; grafted/air-layered 2-3 yrs
- Propagation
- Air-layering, grafting; seed for rootstock only.
Relatives in the Sapindaceae family
Close relatives share many features, so these are the most likely mix-ups.
- RambutanNephelium lappaceum
- PulasanNephelium ramboutan-ake
- LycheeLitchi chinensis
- MamoncilloMelicoccus bijugatus
- AckeeBlighia sapida
Map your longan trees
CanopyTwin keeps every tree on a map with its species, cultivar, photos and history, and counts flowers and fruit from survey photos. It is built for orchards, nurseries and collectors of tropical and rare fruit.
More identification guides: free plant identifier · tropical fruit tree identifier · fruit tree identifier · all species guides