Two unrelated plants, one name
Asimina triloba is a deciduous understorey tree from eastern North America. It belongs to the custard apple family, Annonaceae, and it survives hard frosts. It grows to about five or six metres and it spreads by suckers to form thickets.
Carica papaya is a tropical plant from Central America that is not really a tree at all. It is a giant herb with a hollow, soft trunk and a crown of leaves. It belongs to Caricaceae and it dies at the first hint of frost.
Nothing about the two suggests they should share a name. The confusion is entirely historical and regional.
Leaves compared
| Feature | Pawpaw (Asimina) | Papaya (Carica) |
|---|---|---|
| Leaf type | Simple, one blade | Palmate, deeply lobed |
| Leaf size | Up to 30cm long | Up to 60cm across |
| Leaf edge | Smooth, no teeth | Lobed, wavy |
| Leaf stalk | Short and stout | Long, hollow, up to 60cm |
| Arrangement | Alternate, drooping like a skirt | Clustered in a crown at the top |
| Autumn | Turns yellow and drops | Evergreen in the tropics |
Fruit compared
| Feature | Pawpaw (Asimina) | Papaya (Carica) |
|---|---|---|
| Shape | Irregular, lumpy, kidney-shaped | Elongated and smooth |
| Size | 8-15cm long | 15-45cm long |
| Skin | Thin, green turning yellow-brown | Thick, green turning yellow-orange |
| Flesh | Pale yellow to orange, custard texture | Orange, firm and melon-like |
| Seeds | Large, flat, dark, in a single row | Round, black, packed in a central cavity |
| Taste | Banana and mango, very sweet | Sweet, musky, tropical |
Trunk, flower and climate
- Trunk — pawpaw has a proper woody trunk with smooth grey bark. Papaya has a soft, green, hollow trunk marked with the scars of fallen leaves, and it snaps easily in wind.
- Flower — pawpaw flowers are large, dark maroon and hang downwards, appearing before the leaves. Papaya flowers are small, creamy white or yellow, and grow close to the trunk in the leaf axils.
- Climate — pawpaw needs a cold winter to fruit well. Papaya needs frost-free tropical or subtropical warmth and will die below about minus two degrees.
- Spread — pawpaw forms thickets from underground suckers. Papaya grows as a single plant and is replaced from seed.
Why getting the name right matters
The two have completely different growing requirements, so a plant labelled pawpaw and planted in the wrong climate will simply die. A papaya sold as pawpaw to a gardener in a frosty region will not survive its first winter, and a pawpaw planted in the tropics will never get the chilling it needs to set fruit.
The fruit is also handled differently. Pawpaw fruit ripens very fast once picked and is best eaten within a day or two. Papaya keeps far longer and is often eaten half-ripe in salads as well as ripe.
Pawpaw is one of the most confusing names in fruit. It refers to two plants that are not related, do not grow in the same climate and look nothing alike. In North America, pawpaw means Asimina triloba, a cold-hardy understorey tree with custard-like fruit. In Australia, New Zealand and much of the tropics, pawpaw means papaya, Carica papaya, the fast-growing tropical plant with the orange flesh.
If you are trying to identify a tree and the name you have is pawpaw, the first job is working out which of the two you are actually dealing with. This guide separates them feature by feature.
Frequently Asked Questions
No. In North America pawpaw means Asimina triloba, a cold-hardy tree in the custard apple family. In Australia, New Zealand and the tropics it means papaya, Carica papaya, which is a tropical plant in a different family entirely.