{"id":15,"date":"2007-02-06T23:04:07","date_gmt":"2007-02-07T07:04:07","guid":{"rendered":"https:\/\/www.wkiri.com\/today\/?p=15"},"modified":"2007-02-11T11:58:03","modified_gmt":"2007-02-11T19:58:03","slug":"why-roses-are-red-and-violets-are-blue","status":"publish","type":"post","link":"https:\/\/www.wkiri.com\/today\/?p=15","title":{"rendered":"Why roses are red and violets are blue"},"content":{"rendered":"<p>Today I finished the chapter on vegetables in &#8220;What Einstein Told His Cook 2&#8221;.  One of the tidbits that stuck with me was the fact that (red) roses and violets both have the same pigment; it&#8217;s an <a href=\"http:\/\/en.wikipedia.org\/wiki\/Anthocyanin\">anthocyanin<\/a> that, like litmus paper, responds to pH with a color indicator.  Rose petals are slightly acidic, so the pigment shows up as red, while violets are slightly alkaline and therefore appear blue.  (Gosh, I shouldn&#8217;t have bothered buying that 100-pack of pH indicator paper; I&#8217;ve got 11 rose bushes outside!)<\/p>\n<p>Apparently, the presence of anthocyanin also explains why the new growth on a rosebush is tinted red, but the older leaves are green; new growth that hasn&#8217;t yet begun producing chlorophyll is vulnerable to radiation from the sun, so extra anthocyanin is produced in the meantime, which protects it from UV.<\/p>\n<p>Now I&#8217;m wondering: if I take a violet petal and drop it in some vinegar, will it turn red?  Can I dye my roses with household chemicals?  My roses are actually white, so no telling what would happen in different pH conditions (maybe nothing; the white could mean that they lack anthocyanin).  I hear an experiment begging to be performed this weekend&#8230;<\/p>\n<p><b>Edit:<\/b> I may have to wait on this; I forgot that I&#8217;d just pruned all of my rose bushes down into skeletal stumps of themselves, with no blooms to be had. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Today I finished the chapter on vegetables in &#8220;What Einstein Told His Cook 2&#8221;. One of the tidbits that stuck with me was the fact that (red) roses and violets both have the same pigment; it&#8217;s an anthocyanin that, like litmus paper, responds to pH with a color indicator. Rose petals are slightly acidic, so [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[11],"tags":[],"_links":{"self":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts\/15"}],"collection":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=15"}],"version-history":[{"count":0,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=\/wp\/v2\/posts\/15\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=15"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=15"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wkiri.com\/today\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=15"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}