Berkheya Robusta

''Berkheya'' is a genus of flowering plants in the aster family, Asteraceae, and the subfamily Carduoideae, the thistles. It is distributed in tropical Africa, especially in southern regions.Hind, N. (2006)
568. ''Berkheya purpurea''.
''Curtis's Botanical Magazine'' 23(4), 289-96. Of about 75 species, 71 can be found in South Africa.Funk, V. A. and R. Chan. (2008)
Phylogeny of the spiny African daisies (Compositae, tribe Arctotideae, subtribe Gorteriinae) based on ''trn''L-F, ''ndh''F, and ITS sequence data.
''Molecular Phylogenetics and Evolution'' 48(1), 47-60.

Most species have yellow ray florets, a few have white, and ''B. purpurea'' has light purple or mauve florets.

''B. purpurea'' is cultivated as an ornamental plant. Some ''Berkheya'' are known as weeds.Clark, M. M
A comparison between the flower-head insect communities of South African ''Berkheya'' and European Cynareae.
In: ''Proceedings of the VIII International Symposium on Biological Control of Weeds''. (pp. 165-170). Istituto Sperimentale per la Vegetale, Ministero dell'Agricoltura e delle Foreste. 1990.

''B. 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 acanthopoda''
* ''Berkheya angusta''
* ''Berkheya angustifolia''
* ''Berkheya annectens'' – thistle-thorn
* ''Berkheya armata''
* ''Berkheya barbata''
* ''Berkheya bergiana''
* ''Berkheya bipinnatifida''
* ''Berkheya caffra''
* ''Berkheya canescens''
* '' Berkheya cardopatifolia''
* '' Berkheya carduoides''
* '' Berkheya carlinifolia''
* '' Berkheya carlinoides''
* '' Berkheya carlinopsis''
* '' Berkheya chamaepeuce''
* ''Berkheya cirsiifolia''
* ''Berkheya coddii''
* '' Berkheya coriacea''
* '' Berkheya cruciata''
* ''Berkheya cuneata''
* ''Berkheya debilis''
* '' Berkheya decurrens''
* '' Berkheya densifolia''
* '' Berkheya discolor''
* ''Berkheya draco''
* '' Berkheya dregei''
* '' Berkheya echinacea''
* '' Berkheya eriobasis''
* ''Berkheya erysithales''
* ''Berkheya ferox''
* '' Berkheya francisci''
* '' Berkheya fruticosa''
* ''Berkheya glabrata'' – yellow thistle
* '' Berkheya griquana''
* ''Berkheya herbacea''
* ''Berkheya heterophylla''
* ''Berkheya insignis''
* '' Berkheya latifolia''
* ''Berkheya leucaugeta''
* '' Berkheya mackenii''
* '' Berkheya macrocephala''
* '' Berkheya maritima''
* ''Berkheya montana''
* '' Berkheya multijuga''
* '' Berkheya nivea''
* '' Berkheya onobromoides''
* '' Berkheya onopordifolia''
* ''Berkheya pannosa''
* '' Berkheya pauciflora''
* '' Berkheya pinnatifida''
* '' Berkheya purpurea'' – purple berkheya
* '' Berkheya radula''
* '' Berkheya radyeri''
* '' Berkheya rhapontica''
* '' Berkheya rigida'' – Augusta thistle, Hamelin thistle
* '' Berkheya robusta''
* ''Berkheya rosulata''
* '' Berkheya seminivea''
* ''Berkheya setifera''
* '' Berkheya speciosa''
* '' Berkheya sphaerocephala''
* '' Berkheya spinosa''
* ''Berkheya spinosissima''
* ''Berkheya subulata''
* '' Berkheya tysonii''
* '' Berkheya umbellata''
* '' Berkheya viscosa''
* '' Berkheya zeyheri''

Gallery

File:Berkheya armata (2).jpg, ''Berkheya armata''
File:Berkheya cirsiifolia.jpg, ''Berkheya cirsiifolia''
File:Berkheya purpurea 03.jpg, '' Berkheya purpurea''
File:Berkheya radula01.jpg, '' Berkheya radula''

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.

References

Arctotideae
Asteraceae genera
Flora of Africa
Taxa named by Jakob Friedrich Ehrhart

{{Asteraceae-stub