Is la plume french for pen?

"la plume" was the feather people used to write along with liquid ink in the past. The Words "prendre la plume" is still in the language, as a way to say "to write", but this is becoming pompous:

je prends la plume pour te dire que ... I'm writing to say you that...

the 'nom de plume' is the name writers adopt to get their books published.