Fruit Features in Some Species of Astereae and Helinatheae Alliance

Abstract

Theoretical framework: Astereae is the second largest tribe of Asteraceae, with 170 genera with a worldwide distribution. The Alliance Heliantheae clade consists of about 160 genera from various tribes, including Eupatorieae and Heliantheae. Both taxa, especially Alliance Heliantheae, have taxonomic problems, and the structure of the fruits can reveal useful characters in their taxonomy.   Objective: The fruits of Baccharis uncinella DC., Inulopsis scaposa (DC.) O. Hoffm. (Tribe Astereae), Campovassouria cruciata (Vell.) R. M. King & H. Rob. (Tribe Eupatorieae) and Ichthyothere mollis Baker (Tribe Heliantheae) were ontogenically analyzed and compared with results obtained in studies of species from these three tribes.   Method: Flowers and fruits at different stages of development were collected in Vila Velha State Park, Paraná, Brazil. The botanical material was investigated according to usual techniques in plant anatomy.   Results: The fruits of the two species of Astereae are structurally very similar, being devoid of mesocarp and phytomelanin, unlike the species of Eupatorieae and Heliantheae, which have parenchymatic and sclerenchymatic mesocarp and phytomelanin.   Conclusion: Characters that may be relevant in the taxonomy of both groups of Asteraceae are the absence or presence of mesocarp; presence or absence of phytomelanin, laminar or filamentous pappus, and occurrence/type of twin hairs.