The Chao Phraya is full of water hyacinth, an invasive species originally from South America. It’s a free-floating plant, and you see patches of it floating down the river. The amount of it you see varies from day to day; this morning, you can see a great deal of it from our window:

(In the foreground, you can see the school; to the left, you can see the enormous ferris wheel of Asiatique, which lights up at night. Those boats are hotel boats. The bridge is the Rama III Bridge.)

Here’s what a patch of water hyacinth looks like up close: