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. It is also present in parts of Tanzania, where it is considered an invasive species.[4] Because its fruits explode when ripe, it has also received the colloquial nickname the dynamite tree.[5][6]
| Hura crepitans | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Malpighiales |
| Family: | Euphorbiaceae |
| Genus: | Hura |
| Species: | H. crepitans
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| Binomial name | |
| Hura crepitans | |
| Synonyms[1] | |
Description
editThe sandbox tree can grow to 60 metres (200 ft),[7] and its large ovate leaves grow to 60 cm (2 ft) wide. They are monoecious, with red, un-petaled flowers. Male flowers grow on long spikes, while female flowers grow alone in leaf axils. The trunk is covered in long, sharp spikes that secrete poisonous sap. The sandbox tree's fruits are large, pumpkin-shaped capsules, 3–5 cm (1–2 in) long, 5–8 cm (2–3 in) diameter, with 16 carpels 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).[8] Another source states that seeds are thrown as far as 45 m (150 ft) from a tree, averaging about 30 m (100 ft).[7] High-speed video analysis of its exploding fruit revealed that Hura crepitans seeds fly with backspin[9] as opposed to topspin, which was previously assumed.[7] Backspin helps seeds remain oriented to minimize their drag during flight.[10]
Habitat
editThis 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.
Uses
editIts wood is light enough to make indigenous canoes.[11] Fishermen have been said to use the milky, caustic sap from this tree to poison fish.[12] The Caribs made arrow poison from its sap.[13] The wood is used for furniture under the name "hura". Before more modern forms of pens were invented, the trees' unripe seed capsules were sawn in half to make decorative pen sandboxes (also called pounce pots), hence the name 'sandbox tree'. It has been documented as a herbal remedy.[14]
The seeds contain an oil that is toxic for consumption but can be made into biodiesel and soap; its starchy leftovers can be made into animal feed after cooking.[11]
Gallery
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Large sandbox tree in Honolulu -
Hura crepitans in Vietnam -
Hura crepitans in Saint John, U.S. Virgin Islands -
Spiny trunk of Hura crepitans -
Leaf of Hura crepitans -
Hura crepitans fruit carpel -
Hura crepitans fruit carpel, opposite side
References
edit- ^ "Hura crepitans L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 8 August 2022.
- ^ "Hura crepitans". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 24 December 2017.
- ^ "Hura crepitans" at the Encyclopedia of Life
- ^ "Factsheet – Hura crepitans (Sandbox Tree)".
- ^ a b Vogel, Steven (March 2008). "The Flight of the Seed of Hura crepitans" (PDF). Archived from the original (PDF) on 2013-06-08.
- ^ Allard, H. A. (1950). "The Sandbox Tree and Its Armament". Bulletin of the Torrey Botanical Club. 77 (6): 509–515. doi:10.2307/2482185. JSTOR 2482185.
- ^ a b c Swain, M. D.; Beer, Tom (1977). "Explosive Seed Dispersal in Hura crepitans L. (Euphorbiaceae)". New Phytologist. 78 (3): 695–708. doi:10.1111/j.1469-8137.1977.tb02174.x. JSTOR 2434538.
- ^ Postlethwait, John H.; Hopson, Janet L. (2006). "Plant Reproduction". Modern Biology. Austin, TX: Holt, Rinehart, and Winston. p. 618. ISBN 0-03-065178-6.
- ^ Ribera, Jesse; Desai, Aman; Whitaker, Dwight L (2020-08-17). "Putting a New Spin on the Flight of Jabillo Seeds". Integrative and Comparative Biology. 60 (4): 919–924. doi:10.1093/icb/icaa117. ISSN 1540-7063. PMID 32805037.
- ^ Cooper, Eric S.; Mosher, Molly A.; Cross, Carolyn M.; Whitaker, Dwight L. (2018-03-07). "Gyroscopic stabilization minimizes drag on Ruellia ciliatiflora seeds". Journal of the Royal Society Interface. 15 (140): 20170901. doi:10.1098/rsif.2017.0901. ISSN 1742-5689. PMC 5908531. PMID 29514987.
- ^ a b Cruz, Eniel David; Martinez, Gladys Beatriz (December 2018). "Germinação de sementes de espécies amazônicas: assacu (Hura crepitans L.)". Comunicado Técnico (in Portuguese). 302. Brazilian Agricultural Research Corporation: 2–3.
- ^ Handbook of South American Indians. Vol. 3 (1948). Smithsonian Institution. Retrieved 19 February 2019 – via biodiversitylibrary.org.
- ^ Jones, David E (2007). Poison Arrows: North American Indian Hunting and Warfare. University of Texas Press. ISBN 978-0-292-71428-1.
- ^ "Hura Brasiliensis. From Materia Medica by John Henry Clarke. Homeopathy".
External links
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