Weeds is part of a rare group of US pay-TV shows: The Showtime series starring Mary-Louise Parker has celebrated the taping of its 100th episode.

Showtime's entertainment president, David Nevins, told the Weeds cast and crew on Tuesday that only a few pay-TV series have reached 100 episodes, among them Monk.

Parker and her co-stars, including Kevin Nealon, marked the event with cake and champagne while shooting on location in Los Angeles.

The actress was casually dressed in the blouse and cutoffs that she wore for a scene taped earlier.

Parker plays a pot-dealing suburban mum in Weeds, which will end its eight-year run in September.

Parker and the show's creator, Jenji Kohan, grew emotional as they celebrated the series' milestone. Two more episodes remain to be taped.