Los herbarios: custodios de la biodiversidad.

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The genus Pachylaena (Asteraceae, Mutisieae)

The Andean genus Pachylaena (Asteraceae, Mutisieae) comprises perennial, subrosulate to rosulate herbs, with wide, glaucous and crass leaves, all bilabiate corollas, the marginal ones showy, yellow and/or pink and radiating, and plumose pappus. The genus had traditionally two species: P. atriplicifolia and P. rosea. This study shows that P. rosea should be treated as a synonym of P. atriplicifolia because the two characters of distinction, the colour of the corollas and the morphology of the involucre phyllaries, are shared by both taxa. An overview of the genus Pachylaena and its only species P. atriplicifolia is performed here, which includes descriptions, synonymic lists, illustrations, a distribution map, and ecological aspects.Facultad de Ciencias Naturales y Muse

A new type of Kranz anatomy in Asteraceae

Fil: Peter, Guadalupe. Departamento de Biología, Bioquímica y Farmacia; Universidad Nacional del Sur; Bahia BlancaFil: Katinas, Liliana. División Plantas Vasculares; Facultad de Ciencias Naturales y Museo; Universidad Nacional de La Plat

Typifications in the genus <i>Trichocline</i> (Asteraceae: Mutisieae)

Concerning the genus Trichocline (Asteraceae: Mutisieae), a neotype is designated for the name Bichenia aurea (≡ T. aurea) and lectotypes are designated for the names Onoseris heterophylla (≡ T. heterophylla), T. humilis and T. linearifolia. Nomenclatural and taxonomic information and IUCN conservation status assessments are given for the four species T. aurea, T. heterophylla, T. humilis and T. linearifolia. In addition, a new record of T. heterophylla for Argentina is reported.Facultad de Ciencias Naturales y Muse

Typifications in the genus Trichocline (Asteraceae: Mutisieae)

Fil: Pasini, Eduardo. Programa de Pós-GraduaçÆo em Botânica. Universidade Federal do Rio Grande do Sul. Porto Alegre. Rio Grande do Sul; BrazilFil: Katinas, Liliana. División Plantas Vasculares. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Are the trichomes in corollas of Mutisieae (Asteraceae) really twin hairs?

The corollas of three species of Onoseris, 13 species of Trichocline and one species of Uechtritzia (Asteraceae, Mutisieae) exhibit trichomes that are morphologically similar to the twin hairs which are traditionally considered exclusive of the cypselas in Asteraceae. Four types of trichomes were found: 1-celled, 2-celled, 3-celled, and 4-celled. The 3-celled and 4-celled corolla hairs are those which most resemble the typical cypsela twin hairs. The ontogeny of the corolla hairs was analysed and coincidences with the ontogeny of the cypsela twin hairs were found. (1) An anticlinal division of the epidermal mother cell originates two hair cells which, in turn, originate the basal cells (sometimes one of them is reduced or similar to the epidermal cells) by oblique or periclinal subdivision. (2) In some cases the basal cell(s) of the 3- or 4-celled corolla hair elongates and reaches the same length as the hair cells. The same kind of trichomes have been demonstrated in cypselas of Mutisieae. (3) The 1- and 2-celled corolla hairs have already been described as variants of the cypsela twin hairs. Based on this evidence we conclude that the corolla hairs of Onoseris, Trichocline and Uechtritzia are twin hairs. It is hypothesized that the 1-4 corolla hairs could be involved in water absorption, as occurs in the cypsela twin hairs.Facultad de Ciencias Naturales y Muse

Are the trichomes in corollas of Mutisieae (Asteraceae) really twin hairs?

The corollas of three species of Onoseris, 13 species of Trichocline and one species of Uechtritzia (Asteraceae, Mutisieae) exhibit trichomes that are morphologically similar to the twin hairs which are traditionally considered exclusive of the cypselas in Asteraceae. Four types of trichomes were found: 1-celled, 2-celled, 3-celled, and 4-celled. The 3-celled and 4-celled corolla hairs are those which most resemble the typical cypsela twin hairs. The ontogeny of the corolla hairs was analysed and coincidences with the ontogeny of the cypsela twin hairs were found. (1) An anticlinal division of the epidermal mother cell originates two hair cells which, in turn, originate the basal cells (sometimes one of them is reduced or similar to the epidermal cells) by oblique or periclinal subdivision. (2) In some cases the basal cell(s) of the 3- or 4-celled corolla hair elongates and reaches the same length as the hair cells. The same kind of trichomes have been demonstrated in cypselas of Mutisieae. (3) The 1- and 2-celled corolla hairs have already been described as variants of the cypsela twin hairs. Based on this evidence we conclude that the corolla hairs of Onoseris, Trichocline and Uechtritzia are twin hairs. It is hypothesized that the 1-4 corolla hairs could be involved in water absorption, as occurs in the cypsela twin hairs.Facultad de Ciencias Naturales y Muse

Patagonia : cuna de las margaritas

Fil: Katinas, Liliana. División Plantas Vasculares. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Crisci, Jorge Víctor. Laboratorio de Sistemática y Biología Evolutiva (LASBE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

The unusual occurrence of tricolpate pollen within Mutisieae (Asteraceae)

The monotypic genus Hecastocleis and species of Ainsliaea DC. (Asteraceae, Mutisieae) have tricolpate pollen, which is unusual in Asteraceae. The pollen morphology of H. shockleyi and species of Ainsliaea were studied with light microscope and scanning electron microscope. Pollen of H. shockleyi and some species of Ainsliaea have tricolpate aperture but differ in size and exine features. The pollen of Ainsliaea is bigger than that of Hecastocleis, and has more conspicuous microspines, a Mutisia- or an Ainsliaea-exine type, and is slightly thickened at the poles. The pollen of H. shockleyi is scabrate-microechinate with small puncta, and has the Mutisia-exine type, which is regularly thickened over the complete grain. The occurrence of tricolpate pollen supports previous studies that Hecastocleis and Ainsliaea stand apart from other genera of Mutisieae, but the occurrence of Mutisia-exine type does not suggest complete independence of the tribe.Facultad de Ciencias Naturales y Muse

Clarifications regarding Noël Necker`s names associated to Chaptalia (Asteraceae: Mutisieae)

Fil: Katinas, Liliana. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Plantas Vasculares; Argentin