Morphology and ontogeny of the cypsela hairs of Nassauviinae (Asteraceae, Mutisieae).

FREIRE, S.E. & KATINAS, L.

Advances in Compositae Systematics

Royal Botanic Gardens, Kew

Año: 1995; p. 107 - 143

The study of cypsela hairs is based on mature fruits of ca. 150 species representing 23 genera of nassauviinae. Eight morphological types of non glandular hairs were found. basic (with four subtypes: basic-basic, basic-rounded, basic-filiform and basic-basilate), 2) asymmetric, 3) divergent, 4)radiate, 5) crenate, 6) single 3-celled, 7)single 2-celled, 8) branched; and three types of glandular hairs: 1) uniseriate, 2) typical biseriate, 3) atypical biseriate. Their ontogeny and morphology are described and illustrated. According to their ontogeny, the twin hairs were segregated from the non-twin hairs, and within the former, four types of atypical twin hirs were differentiated.Taxonomically, cipsela hairs appear to be useful in the circumscription of Moscharia-Polyachyrus (basic.basilate), Nassauvia-Triptilion (single 2-celled)and the following genera: Burkartia (basic-rounded), Dolichlasiium (basic-basic), Holocheilus (basic-basic), Leucheria (basic-basic), Lophopappus (basic-basic), Oxyphyllum (basic-basiuc),Panphalea (basic-basic), Pleocarphus (basi-rounded)and Proustia (basic-filiform). A table containing the cypsela hairs types and subtypes for each species is given. Phylogenetically three lines of evolution are proposed within the subtribe: (1) 2-cell hair line, (2) 1-celled hair line, and (3)4-celled hair line developed from an ancestral 4-celled, long hair with two cylindrical apical cells. A comparison between previous analyses of Nassauviinae andour results revealed that the single 2-celled and the basic-basilate cypsela hairs represent synapomorphies for nassauvia-Triptilion and Moscharia-Polyachyrus, respectively; the basic-rounded, basic-filiform, asymmetric/single 3-celled hairs and the glabrous cypselas appear as parallelisms; the divergent/radiate, branched and crenate hairs are autapomorphies for Trixis, T. stricta, and Acourtia, respectively