Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Hura crepitans
open-in-new
<h2 id="description">Description</h2> <p>The sandbox tree can grow to 60 metres (200 ft) in height,<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> and up to 13 metres (44 ft) in girth at 1.8 metres (6 ft) above the ground;<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> its large <a href="/facts/Glossary_of_leaf_morphology/GfSyEn7C">ovate</a> leaves grow to 60 cm (2 ft) wide. The trees are <a href="/facts/Monoecy/Up20kQT3">monoecious</a>, with red, un-petaled flowers. Male flowers grow on long <a href="/facts/Raceme/lXl4udlJ">spikes</a>, while female flowers grow alone in leaf <a href="/facts/Axils/1m6wCNTg">axils</a>. The trunk is covered in long, sharp spikes that secrete poisonous <a href="/facts/Sap/cxdgQYP8">sap</a>. The sandbox tree's fruits are large, <a href="/facts/Pumpkin/CwxGJmej">pumpkin</a>-shaped <a href="/facts/Capsule_(fruit)/nSgcw6KK">capsules</a>, 3–5 cm (1–2 in) long, 5–8 cm (2–3 in) diameter, with 16 <a href="/facts/Carpel/P5qFQMk1">carpels</a> 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).<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> One source states that ripe capsules catapult their seeds as far as 100 m (330 ft).<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a>[<i>verification needed</i>] Another source states that seeds are thrown as far as 45 m (150 ft) from a tree, most commonly 30 m (100 ft).<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> High-speed video analysis of its exploding fruit revealed that sandbox seeds fly with backspin<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> as opposed to topspin, which had been previously assumed.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> Backspin helps seeds remain oriented to minimize their drag during flight.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p> <h2 id="habitat">Habitat</h2> <p>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. </p> <h2 id="uses">Uses</h2> <p>Its wood is light enough that indigenous people used it to make canoes.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> Fishermen have been said to use the milky, caustic sap from this tree to poison fish.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> The <a href="/facts/Island_Caribs/D6IBSdoz">Caribs</a> made <a href="/facts/Arrow_poison/x38bdmE0">arrow poison</a> from its sap.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> 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 called <a href="/facts/Pounce_(calligraphy)/ofzFeRrV">pounce pots</a>) to hold the "sand" used to dry it, hence the name 'sandbox tree'. It has been documented as a herbal remedy.<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> </p><p>The seeds contain an oil that is toxic for consumption but can be made into <a href="/facts/Biodiesel/M6FkfJXH">biodiesel</a> and <a href="/facts/Soap/S3nJa1oY">soap</a>; the starchy leftovers after extracting the oil from the seeds can be made into <a href="/facts/Animal_feed/3pYmdSFB">animal feed</a> after cooking.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> </p> <h2 id="gallery">Gallery</h2> <h2 id="external-links">External links</h2> Wikimedia Commons has media related to Hura crepitans. <ul><li><a href="https://web.archive.org/web/20051228163050/http://www2.fpl.fs.fed.us/TechSheets/Chudnoff/TropAmerican/html_files/huracr1new.html">Center for Wood Anatomy Research, details about the wood of the Sandbox tree</a></li> <li>(in Portuguese) <a href="http://www.esalq.usp.br/trilhas/medicina/am20.php">University of São Paulo: <i>Hura crepitans</i></a> photos</li> <li><a href="http://www.maya-ethnobotany.org/toxic-intoxicating-halucinogenic-mild-altering-poisonous-plants-drugs-warning/hura-polyandra-tree-explodingseed-pod-family-euphorbiaceae-video.php">www.maya-ethnobotany.org seedpod explosion video</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"Hura crepitans". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 24 December 2017. <a href="https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=19419" target="_blank">https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=19419</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Hura crepitans". The Encyclopedia of Life. <a href="https://web.archive.org/web/20230000000000/http://www.eol.org/pages/1156195" target="_blank">https://web.archive.org/web/20230000000000/http://www.eol.org/pages/1156195</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"Factsheet – Hura crepitans (Sandbox Tree)". <a href="http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Hura_crepitans_%28Sandbox_Tree%29.htm" target="_blank">http://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Hura_crepitans_%28Sandbox_Tree%29.htm</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Vogel, Steven (March 2008). "The Flight of the Seed of Hura crepitans" (PDF). Archived from the original (PDF) on 2013-06-08. <a href="https://web.archive.org/web/20130608110356/http://sura.ots.ac.cr/local/florula3/docs/Hura.pdf" target="_blank">https://web.archive.org/web/20130608110356/http://sura.ots.ac.cr/local/florula3/docs/Hura.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>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 href="https://www.jstor.org/stable/2482185" target="_blank">https://www.jstor.org/stable/2482185</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Swain, M. D.; Beer, Tom (1977). "Explosive Seed Dispersal in Hura crepitans L. (Euphorbiaceae)". New Phytologist. 78 (3): 695–708. Bibcode:1977NewPh..78..695S. doi:10.1111/j.1469-8137.1977.tb02174.x. JSTOR 2434538. <a href="https://doi.org/10.1111%2Fj.1469-8137.1977.tb02174.x" target="_blank">https://doi.org/10.1111%2Fj.1469-8137.1977.tb02174.x</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Kingsley, Charles (August 17, 1878). "At Last, Christmas in the West Indies". The Garden. 14 (3521): 53. <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Vogel, Steven (March 2008). "The Flight of the Seed of Hura crepitans" (PDF). Archived from the original (PDF) on 2013-06-08. <a href="https://web.archive.org/web/20130608110356/http://sura.ots.ac.cr/local/florula3/docs/Hura.pdf" target="_blank">https://web.archive.org/web/20130608110356/http://sura.ots.ac.cr/local/florula3/docs/Hura.pdf</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Postlethwait, John H.; Hopson, Janet L. (2006). "Plant Reproduction". Modern Biology. Austin, TX: Holt, Rinehart, and Winston. p. 618. ISBN 0-03-065178-6. <a href="0-03-065178-6" target="_blank">0-03-065178-6</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Swaine, M. D.; Beer, Tom (May 1977). "Explosive Seed Dispersal in Hura crepitans L. (Euphorbiaceae)". New Phytologist. 78 (3): 701–703. Bibcode:1977NewPh..78..695S. doi:10.1111/j.1469-8137.1977.tb02174.x. ISSN 0028-646X. <a href="https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1977.tb02174.x" target="_blank">https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1977.tb02174.x</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>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. <a href="https://doi.org/10.1093/icb/icaa117" target="_blank">https://doi.org/10.1093/icb/icaa117</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Swain, M. D.; Beer, Tom (1977). "Explosive Seed Dispersal in Hura crepitans L. (Euphorbiaceae)". New Phytologist. 78 (3): 695–708. Bibcode:1977NewPh..78..695S. doi:10.1111/j.1469-8137.1977.tb02174.x. JSTOR 2434538. <a href="https://doi.org/10.1111%2Fj.1469-8137.1977.tb02174.x" target="_blank">https://doi.org/10.1111%2Fj.1469-8137.1977.tb02174.x</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>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 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5908531" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5908531</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>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. <a href="https://www.embrapa.br/busca-de-publicacoes/-/publicacao/1100204/germinacao-de-sementes-de-especies-amazonicas-assacu-hura-crepitans-l" target="_blank">https://www.embrapa.br/busca-de-publicacoes/-/publicacao/1100204/germinacao-de-sementes-de-especies-amazonicas-assacu-hura-crepitans-l</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Handbook of South American Indians. Vol. 3 (1948). Smithsonian Institution. Retrieved 19 February 2019 – via biodiversitylibrary.org. <a href="https://www.biodiversitylibrary.org/item/88011" target="_blank">https://www.biodiversitylibrary.org/item/88011</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></p></li> <li id="fn:16"><p>Jones, David E (2007). Poison Arrows: North American Indian Hunting and Warfare. University of Texas Press. ISBN 978-0-292-71428-1. <a href="978-0-292-71428-1" target="_blank">978-0-292-71428-1</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></p></li> <li id="fn:17"><p>"Hura Brasiliensis. From Materia Medica by John Henry Clarke. Homeopathy". <a href="https://www.materiamedica.info/en/materia-medica/john-henry-clarke/hura-brasiliensis" target="_blank">https://www.materiamedica.info/en/materia-medica/john-henry-clarke/hura-brasiliensis</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></p></li> <li id="fn:18"><p>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. <a href="https://www.embrapa.br/busca-de-publicacoes/-/publicacao/1100204/germinacao-de-sementes-de-especies-amazonicas-assacu-hura-crepitans-l" target="_blank">https://www.embrapa.br/busca-de-publicacoes/-/publicacao/1100204/germinacao-de-sementes-de-especies-amazonicas-assacu-hura-crepitans-l</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></p></li> </ol>