In April 2016, the web site High Times published an article reporting that scientists had successfully crossbred marijuana and kale:
A Brooklyn-based lab has successfully bred the world’s first Kale x Cannabis hybrid. The company, Williamsburg Wonders, announced today that the new cross, called Kaleabis, would be available as a superfood juice shot in Oregon dispensaries this summer.
Readers who encountered the above-quoted article either didn't notice the publish date (1 April 2016) or didn't follow the link included at the bottom of the article. While High Times didn't specifically state that the article was an April Fool's Day joke on their web site, they did link to the following image:
While dozens of web sites published their own April Fool's Day joke articles in 2016, many readers didn't encounter them until weeks after the infamous date, making it a little harder to determine whether the articles were jokes.