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 about 20,000 years in the future, at the height of its civilisation. (TV: Timelash, 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)