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The essential oil yield and composition of 17 species of the Asteraceae family were evaluated. Samples were obtained by hydrodistillation of the leaves and inflorescences and they were analyzed by GC-MS and GC-FID. A total of 13 species presented essential oils with yields ranging from 0.06 to 3.36% in fresh samples and from 0.07 to 2.53% in dried samples. Erechtites valerianifolius (Wolf) DC. produced the highest essential oil yield from both fresh and dried samples. Seventy-nine constituents were identified in essential oils from Asteraceae species, mainly consisting of monoterpenes and sesquiterpenes.

Structural features of cypsela are important to certain tribes of Asteraceae; thus, the ontogeny of the fruit (only the pericarp) of 10 weedy Asteraceae species was determined concerning the contribution to increase the knowledge of the fruit development in Asteraceae. The species analyzed are Conyza bonariensis L. (Cronquist.), Cosmos sulphureus Cav., Eclipta alba L. Hassk., Elephantopus mollis Kunth., Emilia sonchifolia L. DC., Galinsoga quadriradiata Ruiz & Pav., Erechtites valerianifolius (Wolf) DC., Parthenium hysterophorus L., Praxelis clematidea (Griseb) R.M. King & H. Rob and Sigesbeckia orientalis L. The mesocarp in the cypsela structure shows variation in the number of layers, the cell layer arrangement of the sclerenchyma and parenchyma, and the presence of phytomelanin that is especially striking. The mesocarp traits of Heliantheae alliance species are homogeneous, and it has been suggested that the derived character phytomelanin may not have the same evolutionary history in species ...

Erechtites valerianifolius DC. (1838: 295). Distribution: a native of troical America, invasive in other tropical regions. = Senecio boninsimae Yatabe (1893: 1–3) Lectotype (designated here)—Bot. Mag. (Tokyo) vol. 7, plate II. 1893. No specimens were cited in the protologue of Senecio boninsimae, but one detailed drawing (plate II) was provided. Kitamura (1934) recorded this name as a synonym for Erechtites valerianifolius DC., citing “Bonin (S. Nishimura)”. The specimens collected by S. Nishimura were found at TI, but specimens collected before 1893 have not been found in any herbaria. Because we have not found adequate specimens that could serve as the type of this taxon in any herbaria, “plate II” should be regarded as the lectotype (ICBN Art. 9.2.)., Published as part of Watanabe-Toma, Kana, Ohi-Toma, Tetsuo & Murata, Jin, 2011, Typification of Angiospermae described from the Bonin Islands 1: Metachlamydeae, pp. 51-58 in Phytotaxa 33 on page 56, DOI: 10.11646/phytotaxa.33.1.4, http://zenodo.org/record/4894593, {"references":["Yatabe, R. (1893) New or little known plants of Japan. Botanical Magazine (Tokyo) 7: 1 - 3.","Kitamura, S. (1934) Compositae novae Japonicae VII. Acta Phytotaxonomica et Geobotanica 3: 97 - 111."]}