The subfamily Mutisioideae (Asteraceae

KATINAS, L.; PRUSKI, J.; SANCHO, G.; TELLERIA, M.C.

BOTANICAL REVIEW

Springer Science

Lugar: New York; Año: 2008 vol. 74 p. 469 - 716

0006-8101

The subfamily Mutisioideae (Asteraceae), which comprises three tribes, Mutisieae, Nassauvieae, and Stifftieae, is analyzed at the generic level. A total of 87 genera traditionally considered or related to Mutisioideae were studied. The key characters for the family, i.e., corollas, anthers, styles, and pollen, are analyzed and discussed. The 74 genera accepted here in Mutisioideae are described and illustrated, and keys to tribes and genera, as well as comparative tables showing main morphological and palynological characters of the genera, are given. Pollen of 45 species belonging to 27 genera (Actinoseris (Endl.) Cabrera, Adenocaulon Hook., Burkartia Crisci, Cephalopappus Nees & Mart., Chimantaea Maguire, Steyerm. & Wurdack, Chucoa Cabrera, Cnicothamnus Griseb., Duidaea S. F. Blake, Eriachaenium Sch. Bip., Eurydochus Maguire & Wurdack, Glossarion Maguire & Wurdack, Gochnatia Kunth, Gongylolepis R. H. Schomb., Leibnitzia Cass., Lycoseris Cass., Macrachaenium Hook. f., Macroclinidium Maxim., Myripnois Bunge, Neblinaea Maguire & Wurdack, Nouelia Franch., Oxyphyllum Phil., Perdicium L., Pertya Sch. Bip., Quelchia N. E. Br., Stenopadus S. F. Blake, Stifftia J. C. Mikan, and Stomatochaeta (S. F. Blake) Maguire & Wurdack) is described for the first time or re-described with additional detail. Three new exine types are described: Gongylolepis, Macroclinidium, and Stenopadus types. The study led to the following main conclusions. The style features (smooth, rugulose to papillose styles, the papillae being relatively short and rounded) differ from the carduoid, arctotoid, and vernonioid styles and constitute the main characters for delimiting the subfamily Mutisioideae. The presence and distribution of the style papillae support the recognition of three tribes: (a) those genera with smooth styles, or with dorsally papillose styles with the papillae distributed above the branch bifurcation point, belong to the tribe Mutisieae (43 genera, ca. 500 species); (b) those genera with styles rugulose or papillose above and below the branch bifurcation point, almost reaching the style base, belong to the tribe Stifftieae (6 genera, 48 species); and (c) those genera with the papillae gathered in a tuft at the apex of the style branches belong to the tribe Nassauvieae (25 genera, ca. 315 species). The pollen morphology (i.e., pollen surface psilate, microechinate or echinate, with the exine structure densely columellate) is helpful secondarily in delimitating the Mutisioideae. The pollen of Nassauvieae can be clearly differentiated from the pollen of Mutisieae and Stifftieae. It is microechinate, with few developed microspines; the exine is distinctly bilayered, and both the ectosexine and the endosexine are clearly columellate. Otherwise, the pollen of Mutisieae and Stifftieae is psilate, microechinate or echinate, with a compact ectosexine formed by very thickly disposed columellae and a clearly columellate endosexine. The tribes Nassauvieae and Stifftieae are morphologically homogeneous, whereas the tribe Mutisieae is heterogeneous for most of its morphological features (e.g., corolla shape, pollen morphology). The morphology supports molecular studies in the exclusion of some genera (Brachylaena R. Br., Cloiselia S. Moore, Dicoma Cass., Duseniella K. Schum., Erythrocephalum Benth., Gladiopappus Humbert, Hesperomannia A. Gray, Macledium Cass., Moquinia DC., Pasaccardoa Kuntze, Pleiotaxis Steetz, Tarchonanthus L., and Warionia Benth. & Coss.) but not the exclusion of others, for example, Hecastocleis A. Gray, the members of the Gochnatia complex, or the members of the Ainsliaea DC. group. The morphologically closest subfamilies to Mutisioideae are Barnadesioideae in corolla shape (both have the same range of corolla types except that true ray and filiform corollas are present only in Mutisioideae) and style features (smooth, rugulose to papillose styles, the papillae being relatively short and rounded) and Carduoideae in pollen features (both have the Anthemoid exine pattern as well as some genera with echinate and highly perforate surfaces).