| Hura crepitans | |
|---|---|
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Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Euphorbiaceae |
| Genus: | Hura |
| Species: | H. crepitans |
| Binomial name | |
| Hura crepitans | |
| Synonyms[1] | |
Hura crepitans, thesandbox tree,[2] also known aspossumwood,monkey no-climb,assacu (fromTupiasaku) andjabillo,[3] is an evergreen tree in the familyEuphorbiaceae, native to tropical regions of North and South America including theAmazon rainforest. It is also present in parts of Tanzania, where it is considered aninvasive species.[4] Because its fruitexplodes when ripe, it has also received the colloquial nickname the "dynamite tree".[5][6]
The sandbox tree can grow to 60 metres (200 ft) in height,[7] and up to 13.2 metres (43 ft) in girth at 1.8 m (6 ft) above the ground;[8] its largeovate leaves grow to 60 cm (2 ft) wide. The trees aremonoecious, with red, un-petaled flowers. Male flowers grow on longspikes, while female flowers grow alone in leafaxils. The trunk is covered in long, sharp spikes that secrete poisonoussap. The fruit are large,pumpkin-shapedcapsules, 3–5 cm (1–2 in) long, 5–8 cm (2–3 in) diameter, with 16carpels arranged radially. Its seeds are flattened and about 2 cm (3⁄4 in) diameter. The capsules explode when ripe, splitting into segments and launching seeds at 70 m/s (250 km/h; 160 mph).[5] One source states that ripe capsules catapult their seeds as far as 100 m (330 ft).[9][verification needed] Another source states that seeds are thrown as far as 45 m (150 ft) from a tree, most commonly 30 m (100 ft).[10] High-speed video analysis of its exploding fruit revealed that sandbox seeds fly with backspin[11] as opposed to topspin, which had been previously assumed.[7] Backspin helps seeds remain oriented to minimize theirdrag during flight.[12]
This tree prefers wet soil, and partial shade or partial to full sun. It is often cultivated for shade. Sandbox trees are tropical trees and prefer warmer, more humid environments.
Its wood is light enough that indigenous people used it to make canoes.[13] Fishermen have been said to use the milky, caustic sap from this tree to poison fish.[14] TheCaribs madearrow poison from its sap.[15]The wood is used for furniture under the name "hura". In a time when most writing pens left wet ink on the page, the trees' unripe seed capsules were sawn in half to make decorative boxes (also calledpounce pots) to hold the "sand" used to dry it, hence the name 'sandbox tree'. It has been documented as a herbal remedy.[16]
The seeds contain an oil that is toxic for consumption but can be made intobiodiesel andsoap; the starchy leftovers after extracting the oil from the seeds can be made intoanimal feed after cooking.[13]
