Berkheya


Berkheya is a genus of flowering plants in the family Asteraceae. It is distributed in tropical Africa, especially in southern regions. Of about 75 species, 71 can be found in South Africa.
Most species have yellow ray florets, a few have white, and B. purpurea has light purple or mauve florets.
Berkheya purpurea is cultivated as an ornamental plant. Some Berkheya are known as weeds.
Berkheya coddii is a well-known hyperaccumulator. Concentration of Ni as the leaves of this species may reach 7.6% DW Ni.
The genus was named in honor of the Dutch scientist and artist Johannes le Francq van Berkhey.
Berkheya are associated with a variety of weevils in the genus Larinus. The tephritid fruit fly Urophora agromyzella is also found on the plants.

Species

Species include:Berkheya acanthopodaBerkheya angustaBerkheya angustifoliaBerkheya annectens – thistle-thornBerkheya armataBerkheya barbataBerkheya bergianaBerkheya bipinnatifidaBerkheya caffraBerkheya canescensBerkheya cardopatifoliaBerkheya carduoidesBerkheya carlinifoliaBerkheya carlinoidesBerkheya carlinopsisBerkheya chamaepeuceBerkheya cirsiifoliaBerkheya coddiiBerkheya coriaceaBerkheya cruciataBerkheya cuneataBerkheya debilisBerkheya decurrensBerkheya densifoliaBerkheya discolorBerkheya dracoBerkheya dregeiBerkheya echinaceaBerkheya eriobasisBerkheya erysithalesBerkheya feroxBerkheya francisciBerkheya fruticosaBerkheya glabrata - yellow thistleBerkheya griquanaBerkheya herbaceaBerkheya heterophyllaBerkheya insignisBerkheya latifoliaBerkheya leucaugetaBerkheya mackeniiBerkheya macrocephalaBerkheya maritimaBerkheya montanaBerkheya multijugaBerkheya niveaBerkheya onobromoides Berkheya onopordifoliaBerkheya pannosaBerkheya paucifloraBerkheya pinnatifidaBerkheya purpurea - purple berkheyaBerkheya radulaBerkheya radyeriBerkheya rhaponticaBerkheya rigida - Augusta thistle, Hamelin thistleBerkheya robustaBerkheya rosulataBerkheya seminiveaBerkheya setiferaBerkheya speciosaBerkheya sphaerocephalaBerkheya spinosaBerkheya spinosissimaBerkheya subulataBerkheya tysoniiBerkheya umbellataBerkheya viscosa

Phylogeny

Comparison of DNA has indicated that Berkheya in its current composition is paraphyletic because some of its species are more related to Cullumia, Cuspidia, Didelta and Heterorhachis than all species currently recognised as Berkeya among each other.