The genus Cotula (Asteraceae) in New Guinea. Sertulum Papuanum 21

In the course of studying the Asteraceae for a proposed Alpine Flora of New Guinea the first author selected the genus Cotula for this separate paper as it showed some variability that was not easily explained. While working on this, Dr. Lloyd’s paper on the genus in the New Zealand Journal of Botany 10 (1972) 277, came to his notice and on corresponding with him it turned out that he had studied the New Guinea species already to some extent but had nothing ready for publication. At the same time, Dr. J. Koster of Leiden, Netherlands, was known to work on a study of all Asteraceae of New Guinea and it soon transpired that when the manuscript was finished and a copy sent to her that very same day she had put down the first words of her manuscript on this genus. She generously allowed us to go ahead with our publication and after Dr. Lloyd had reviewed the first author’s manuscript the paper developed as presented here. This group of small, mat-forming species has been known in New Guinea to date only by C. leptoloba Mattfeld, described from the Wharton Ra. in Papua. Since then, however, it has been collected in several other regions ranging from the Carstensz Mts. in West New Guinea to Mt. Aniata in the southeastern tip of Papua. At first glance the material looked rather homogenous, but on closer look it turned out that at least one species, the material from Mt. Wilhelmina, had to be taken out as new. At this stage, various papers by Dr. Lloyd from Christchurch, New Zealand, drew attention to the group more forcibly and critically. The material available was studied by Dr. Lloyd and he came to the conclusion that at least 4 species should be distinguished, with which the senior author could concur. The differences between the 4 species recognised here are considerable, but the species limits are not well known and the descriptions may need revising when further material is available. Three new species are described below and C. leptoloba is redescribed to include the variation observed in specimens from new localities.