A CLADISTIC ANALYSIS OF LUCILIA CASS. (COMPOSITAE, INULEAE).

Abstract

Abstract- Lucilia is a South American genus with 23 species restricted to disjunct areas in southeastern Brazil and along the Andes. Lucilia is a monophyletic group defined by the co-occurrence of six characters: herbaceous, alternate-leaved, pappus with scabrid bristles fused at the base into a ring, style-branches with sweeping hairs far down, capitula sessile, and aseptate-flagellate hairs. A dadogram is presented using 41 morphological and anatomical characters arranged into 26 transformation series. The polarity of character states was determined by outgroup comparison with the genus Berroa. The cladistic analysis showed extensive parallel evolution in a number of the more conspicuous characters and produced four unresolved trichotomies. However, basing the hierarchy of Lucilia on the branching pattern produced by cladistic analysis results in a more natural and predicitive classification. Lucilia is divided into three sections, Lucilia, Intermedieae (sect, nov), and Lucilioides [divided into two subsections, Subspicata (subsect. nov.) and Lucilioides]. The latter subsection is subdivided into two series, Lucilioides (ser. nov.) and Paralucilia. The Brazilian species of section Lucilia (acutijolia, linearifolia, ferruginea, tmentosa, recurva, nitens, and flagelliformis) form the most primitive group within the genus. The more derived species of the genus, section lucilioides (plicatifolia, catamarcensis, burkartii, subspkata, lopezmirandae, alpina, pickeringii, piptolepis, santamca, chilensis, schultzii, longifolia, radians, lehmanni, pusilla) are found in the Andes L. eriophora (section Intermedieae) from central Chile bridges these two groups. An explanation for the distribution of the genus is given, based on the ecology of the species in relation to theories of the geologic and climatic history of South America. The present pattern has been determined by the age, geographical range, and vicissitudes of the habitat in which each group occurs. In the Brazilian species group, the habitat is old, and has remained relatively stable since well before the Pleistocene. In the Andean species group, the habitat is young and has undergone numerous rapid alterations since its inception at the end of the Pliocene.