how to construct specific mercurial ignore patterns?

I would like to ignore all files that start with:

._

How would I write this in the .hgignore file?

From stackoverflow

• $ cat .hgignore
  syntax: glob
  ._*
  

  Which I have tested thusly (with some "noise" like .. removed for clarity):

  $ ls -aRF
  .:
  a  ._a   .hgignore  sub/
  
  ./sub:
  a  ._a
  $ hg stat
  ? .hgignore
  ? a
  ? sub/a