New Combinations in Chamaesyce (Euphorbiaceae) from Queensland, Australia

Abstract

The new combinations Chamaesyce carissoides (F. M. Bailey) D. C. Hassall ex P. I. Forster & R. J. F. Henderson, C. centralis (B. G. Thompson) P. I. Forster & R. J. F. Henderson, C. coghlanii (F. M. Bailey) D. C. Hassall ex P. I. Forster & R. J. F. Henderson, C. petala (Ewart & L. R. Kerr) P. I. Forster & R. J. F. Henderson, and C. psammogeton (P. S. Green) P. I. Forster & R. J. F. Henderson are made. Recognition of Chamaesyce S. F. Gray as a genus distinct from Euphorbia L. has received considerable support (e.g., Hassall, 1976; Koutnik, 1984, 1987; Smith, 1981; Webster, 1994) or rejection (e.g., Radcliffe-Smith, 1980; McPherson & Tirel, 1987; Oudejans, 1990) among taxonomists. Revisions of Chamaesyce and Euphorbia s. str. in Australia were undertaken by Hassall (1977a). These were unfortunately never published in full; only a revision of the latter genus (Hassall, 1977b), valid transfers of some names into Chamaesyce (Hassall, 1976), and discussion of arid zone speciation patterns (Hassall, 1982) appeared in print. Recognition of Chamaesyce in Australia subsequent to Hassall's work has not been widespread, with most authors opting for a broadly circumscribed Euphorbia (e.g., Forster, 1993, 1994; 0Green, 1993; Forster & Henderson, 1994; Thompson, 1992; Weber, 1986; Wheeler, 1987) as opposed to the narrower view of James and Harden (1990). Despite this lack of local support, we are now of the opinion that the arguments proposed by Hassall (1976), Koutnik (1984, 1987), and Webster (1994) for recognizing Chamaesyce as a genus in its own right are convincing and that their views should be supported. As a new edition of Vascular Plants Names and Distribution the Queensland Herbarium (BRI) census of Queensland Plants in which the authors intend to recognize Chamaesyce as a distinct genus is soon to be prepared, new names are required for certain taxa. While valid combinations exist in Chamaesyce for the majority of taxa that occur in Queensland, no combinations exist for five species. Therefore, these combinations are made here. Two of these combinations were listed in the unpublished thesis of Hassall (1977a) but never published. 1. Chamaesyce carissoides (F. M. Bailey) D. C. Hassall ex P. I. Forster & R. J. F. Henderson, comb. nov. Basionym: Euphorbia carissoides F. M. Bailey, Queensland Agric. J. 16: 449. 1906. TYPE: Australia. Queensland: Cook District, Herberton, Ringrose [AQ342536] (holotype, BRI). 2. Chamaesyce centralis (B. G. Thompson) P. I. Forster & R. J. F. Henderson, comb. nov. Basionym: Euphorbia centralis B. G. Thompson, Nuytsia 8: 353. 1992. TYPE: Australia. Northern Territory: 3 km SW of Alice Springs, 18 Jan. 1990, Thompson 3408 (holotype, DNA not seen; isotypes, BRI; AD & CANB not seen). 3. Chamaesyce coghlanii (F. M. Bailey) D. C. Hassall ex P. I. Forster & R. J. F. Henderson, comb. nov. Basionym: Euphorbia coghlanii F. M. Bailey, Bot. Bull. 13: 12. 1896. TYPE: Australia. Queensland: Gregory North District, Roxborough, Georgina River, Dec. 1895, Bailey [AQ342538] (holotype, BRI). 4. Chamaesyce petala (Ewart & L. R. Kerr) P. I. Forster & R. J. F. Henderson, comb. nov. Basionym: Euphorbia petala Ewart & L. R. Kerr, Proc. Roy. Soc. Victoria, New Series 39(1): 1. 1926. TYPE: Australia. Northern Territory: Wycliffe Well, June 1924, Ewart (holotype, MEL not seen). 5. Chamaesyce psammogeton (P. S. Green) P. I. Forster & R. J. F. Henderson, comb. nov. Basionym: Euphorbia psammogeton P. S. Green, Kew Bull. 48: 314. 1993. TYPE: Australia. Lord Howe Island: Blinky Beach, 13 Nov. 1963, Green 1625 (holotype, K not seen; isotype, A not seen).