Hura crepitans

Hura crepitans, the sandbox tree,[2] also known as possumwood, monkey no-climb, assacu (from Tupi asaku) and jabillo,[3] is an evergreen tree in the family Euphorbiaceae, native to tropical regions of North and South America including the Amazon rainforest.

[4] Because its fruits explode when ripe, it has also received the colloquial nickname the dynamite tree.

The trunk is covered in long, sharp spikes that secrete poisonous sap.

[10] High-speed video analysis of its exploding fruit revealed that Hura crepitans seeds fly with backspin[11] as opposed to topspin, which was previously assumed.

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 called pounce pots) to hold the "sand" used to dry it, hence the name 'sandbox tree'.