{"id":557410,"date":"2026-07-19T12:17:08","date_gmt":"2026-07-19T12:17:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/557410\/"},"modified":"2026-07-19T12:17:08","modified_gmt":"2026-07-19T12:17:08","slug":"its-4500-years-old-180km-across-and-cloned-itself-from-a-single-seedling-meet-the-largest-most-humongous-plant-on-the-planet","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/557410\/","title":{"rendered":"It\u2019s 4,500 years old, 180km across and cloned itself from a single seedling \u2013 meet the largest, most humongous plant on the planet"},"content":{"rendered":"

In the shallow waters of Western Australia\u2019s Shark Bay lies a beautiful\u00a0seagrass<\/a>\u00a0meadow. Often known as Poseidon’s ribbon weed\u00a0(Posidonia australis) \u2013 after Poseidon, the Greek god of the sea \u2013 strapweed or fireball weed, its green fronds waft gently in the shallow waters of the bay.\u00a0<\/p>\n

But this seagrass meadow had been hiding a secret for thousands of years.\u00a0<\/p>\n

Researchers were astounded when they realised this extensive 77-square-mile meadow \u2013 larger than the Caribbean country of Aruba \u2013 was made up of one individual that had cloned itself to reach this epic size over around 4,500 years.\u00a0<\/p>\n

\u201cWe often get asked how many different plants are growing in seagrass meadows and this time we used genetic tools to answer it,\u201d says evolutionary biologist Dr Elizabeth Sinclair, from UWA\u2019s School of Biological Sciences and the UWA Oceans Institute in a\u00a0statement<\/a>.<\/p>\n

So, they used genetic tools to try and find out the answer.\u00a0<\/p>\n

\u201cThe answer blew us away \u2013 there was just one!\u201d adds UWA student researcher Jane Edgeloe. \u201cOne plant has expanded over 180km in Shark Bay, making it the largest known plant on earth.<\/p>\n

The discovery was described in the journal\u00a0Proceedings of the Royal Society B: Biological Sciences<\/a>\u00a0in June 2022.<\/p>\n

\u201cSpawned from a single seed, based on this species’ growth rate [\u2026] it is estimated to be around 4,500 years old,\u201d writes\u00a0Guinness World Records<\/a>\u00a0in its entry confirming Shark Bay\u2019s Posidonia australis seagrass is the world\u2019s largest plant by area. \u201cIt has spread over the millennia via underground clonal shoots known as rhizomes meaning that the entire plant is connected and shares the same DNA, though the authors of the study note that certain patches (ramets) in a clonal plant can become separated over time so gaps can emerge.\u201d<\/p>\n

Aside from being a giant clone of itself (the seagrass meadow is also the world\u2019s largest clone, as it happens), there\u2019s something else weird about this gigantic plant: it has twice as many chromosomes as it should.\u00a0<\/p>\n

Diploids \u2013 including humans \u2013 have one complete set of chromosomes from each parent (two sets in total) while polyploids have more than two complete sets. The experts believe this happened because the plant is a hybrid of two diploid \u2018parent\u2019 plants.\u00a0<\/p>\n

\u201cThe new seedling contains 100 per cent of the genome from each parent, rather than sharing the usual 50 per cent,\u201d explains Sinclair.\u00a0\u201cPolyploid plants often reside in places with extreme environmental conditions, are often sterile, but can continue to grow if left undisturbed, and this giant seagrass has done just that.\u201d<\/p>\n

Seagrass is the only flowering plant that spends its entire life fully immersed in saltwater. Like other seagrass meadows, this habitat is an important carbon store and supports many different animals including fishes,\u00a0turtles<\/a>\u00a0and\u00a0dugongs<\/a>.<\/p>\n

Despite having survived for thousands of years, the future of Shark Bay\u2019s\u00a0Posidonia australis\u00a0isn\u2019t certain. A marine heatwave in 2010\u20132011 damaged around\u00a0one third<\/a>\u00a0of the enormous meadow and could have released vast amounts of carbon dioxide into the atmosphere.\u00a0Protecting seagrass meadows is vital, write the authors of a 2018 study describing the losses caused by this event: \u201cWith heatwaves predicted to increase with further climate\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"In the shallow waters of Western Australia\u2019s Shark Bay lies a beautiful\u00a0seagrass\u00a0meadow. Often known as Poseidon’s ribbon weed\u00a0(Posidonia…\n","protected":false},"author":2,"featured_media":557411,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-557410","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/557410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=557410"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/557410\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/557411"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=557410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=557410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=557410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}