Revision and Phylogeny of Agrostistachys and Chondrostylis (Euphorbiaceae)

The genera Agrostistachys and Chondrostylis, subtribe Agrostistachydeae, have been revised. Chondrostylis comprises two species, C. bankana appears to be much more widespread than was assumed. Agrostistachys comprises six species, one of which is new ( (A. staminodiatus), while several species (e.g. A. intramarginalis and A. meeboldii) have been reduced to the now quite variable A. borneensis, formerly mainly known as. A. longifolia. A phylogenetic analysis of the subtribe Agrostistachydeae shows that all four genera (also Cyttaranthus and I Pseudagrostistachys) are monophyletic; however, the position of Agrostistachys is very weak and the genus may easily change to a paraphyletic group with the other genera nested in it. Even in spite of the weak support for Agrostistachys all genera are maintained in their present circumscription.