Karfel

Karfel was a planet inhabited by humanoids known as Karfelons. (TV: Timelash) It was located in the same galactic cluster as Earth. (PROSE: Speed of Flight)

Astronomical Data
Karfel had diplomatic relationships with the planet of the Bandrils. A council in the Citadel governed life on Karfel. (TV: Timelash)

Somewhere on the planet was a leisure garden with singing plants. (TV: Death of the Doctor)

History
The Third Doctor first visited the planet with Jo Grant and Mike Yates (TV: Timelash) about 20,000 years in the future, at the height of its civilisation. (PROSE: Speed of Flight) Jo also visited a leisure garden with singing plants. (TV: Death of the Doctor)

During this visit, a local artist painted a mural of the Third Doctor in the Citadel. Jo gave a locket containing a photo of herself to the father of a Karfelon named Katz. The Doctor reported to the local authorities the "unethical" experiments of a scientist named Megelen on a local life form called Morloxes.

The Sixth Doctor's TARDIS became trapped by a kontron tunnel and landed on Karfel once again. By this time, Megelen, as the Borad, now ruled the planet as a dictator with the aid of androids. The Borad created the kontron tunnel, which he called the Timelash, and used it as a means to exile his enemies.

With his companion Peri and a young H. G. Wells, the Doctor freed Karfel of the Borad and averted a war with the Bandrils. (TV: Timelash).

As well as the singing flower, there was a flower with purple petals that could shoot acid. (TV: Timelash)