Just learned this morning

[Figarosmom]

That the flower plant grows from tubers as well as seeds. At the end of the season you can dig up and store the tubers just like you do with dahlias. Then next year plant the tubers and they'll flower weeks ahead of the time they would with seed.

I'll still collect 4 o'clock seeds because they are so easy to collect..

Does anyone know of any other annuals like this that will form tubers that can be stored for use the following year?

[eppur_se_muova]

1. I just learned "four o'clock" is the name of a plant. Without that, I had no idea what you were talking about !

Mirabilis jalapa, the marvel of Peru[1] or four o'clock flower, is the most commonly grown ornamental species of Mirabilis plant, and is available in a range of colors. Mirabilis in Latin means wonderful and Jalapa (or Xalapa) is the state capital of Veracruz in Mexico. Mirabilis jalapa is believed to have been cultivated by the Aztecs for medicinal and ornamental purposes.

https://en.wikipedia.org/wiki/Mirabilis_jalapa

One more thing named after Jalapa ! In this case, it's "the Jalapa" in Peru, whereas the city of Jalapa in Mexico gave us the names Jalapeno and, apparently, (through Procrustean mangling by anglophones) "jalopy".