Clitoria ternatea
A very common widely-grown climber. The individual flowers are very pretty upside-down pea-like blue flowers, but as far as I am concerned, this is a very pernicious weed.
The flowers are sparse, so it does not look much like a cultivated plant and it is extremely invasive, showering seeds over a wide area. The plants are very strong climbers growing at least 5 m, with deep roots (so the plant is difficult to remove). The plants frequently dies back, so you are left with masses of dead stems, with the live stems growing among the mats.
The flowers are sparse, so it does not look much like a cultivated plant and it is extremely invasive, showering seeds over a wide area. The plants are very strong climbers growing at least 5 m, with deep roots (so the plant is difficult to remove). The plants frequently dies back, so you are left with masses of dead stems, with the live stems growing among the mats.