What's that awful smell? Cat urine? Semen? Rancid butter? Possibly one of these gorgeous city trees? Hosted by: Hank Green ---------- Support SciShow by becoming a patron on Patreon: https://www.patreon.com/scishow ---------- Dooblydoo thanks go to the following Patreon supporters: Kevin Bealer, Mark Terrio-Cameron, KatieMarie Magnone, Patrick Merrithew, D.A. Noe, Charles Southerland, Fatima Iqbal, Sultan Alkhulaifi, Nicholas Smith, Tim Curwick, Alexander Wadsworth, Scott Satovsky Jr, Philippe von Bergen, Bella Nash, Chris Peters, Patrick D. Ashmore, Piya Shedden, Charles George ---------- Looking for SciShow elsewhere on the internet? Facebook: http://www.facebook.com/scishow Twitter: http://www.twitter.com/scishow Tumblr: http://scishow.tumblr.com Instagram: http://instagram.com/thescishow ---------- Sources: http://www.slate.com/articles/health_and_science/science/2016/10/why_we_still_plant_smelly_ginkgo_trees.html http://arnoldia.arboretum.harvard.edu/pdf/articles/2008-66-2-wake-up-and-smell-the-ginkgos.pdf https://motherboard.vice.com/en_us/article/qk97b3/trees-smell-like-vomit-jizz-barf-semen-spring https://www.pubs.ext.vt.edu/3010/3010-1464/3010-1464.html http://www.dcnr.state.pa.us/cs/groups/public/documents/document/dcnr_010311.pdf http://extension.psu.edu/natural-resources/forests/private/tools-resources/publications/invasive-plants-and-insects/tree-of-heaven ------ Images: https://en.wikipedia.org/wiki/File:Ginkgo_Biloba_Leaves_-_Black_Background.jpg https://en.wikipedia.org/wiki/File:GinkgoLeaves.jpg https://en.wikipedia.org/wiki/File:Ginkgo_biloba_MacAbee_BC.jpg https://en.wikipedia.org/wiki/File:Ginkgo-biloba-male.JPG https://en.wikipedia.org/wiki/File:GingkoFruitingTwigSpring.jpg https://commons.wikimedia.org/wiki/File:Gingko_fg01.jpg#/media/File:Gingko_fg01.jpg https://en.wikipedia.org/wiki/File:Pyrus_calleryana.JPG#/media/File:Pyrus_calleryana.JPG https://en.wikipedia.org/wiki/Ailanthus_altissima#/media/File:G%C3%B6tterbaum_(Ailanthus_altissima).jpg