Oxalidaceae
How to identify a starfruit tree
Averrhoa carambola · also called carambola (Spanish/Portuguese), khế (Vietnamese)
Waxy yellow, ribbed fruit that slices into star shapes; sweetness varies widely by cultivar. Often bears two crops a year in favorable climates. Contains oxalic acid, so it carries a caution for people with kidney disease.
Field marks
These features are typical of the genus Averrhoa, 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 many leaflets.
- Starfruit is five-ridged and star-shaped in cross section; bilimbi fruit is small, cucumber-like, very sour, and often hangs straight from the trunk.
Check a photo
Photograph one whole, mature leaf from above, or a flower or fruit, and the identifier will return ranked matches. If starfruit 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
- Southeast Asia (Indonesia / Sri Lanka region)
- USDA zones
- 9b-11
- Climate
- Tropical to subtropical, moderate cold sensitivity (young trees especially frost-tender).
- Fruiting season
- August, September, December and January (typical, Northern Hemisphere)
- How often grown
- Widely grown
Fruit is the most reliable way to confirm an identification, so August, September, December and January 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 3-5 yrs; grafted 1-2 yrs
- Propagation
- Grafting (seedlings vary widely in sweetness and oxalate levels), air-layering.
Relatives in the Oxalidaceae family
Close relatives share many features, so these are the most likely mix-ups.
Map your starfruit 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