Gisela Sancho

The Subfamily Mutisioideae (Asteraceae)

The subfamily Mutisioideae (74 genera, ca. 865 species), which comprises three tribes, Mutisieae (43 genera, ca. 500 species), Nassauvieae (25 genera, ca. 315 species), and Stifftieae (six genera, 48 species), is analyzed at the generic level. A total of 87 genera traditionally related to Mutisioideae were studied. The genera of Mutisioideae are described and illustrated, and keys to tribes and genera are given. Corollas, anthers, styles, and pollen, are analyzed and discussed. The styles (smooth, rugulose to papillose, papillae short and rounded) constitute the main characters for delimiting the subfamily. The presence and distribution of the style papillae support the recognition of three tribes, although other characters as corolla shape contribute to their definition. The pollen of Nassauvieae can be clearly differentiated from the pollen of Mutisieae and Stifftieae. The morphology supports the exclusion of Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, and Warionia but not the exclusion of other taxa, for example, Hecastocleis, the Gochnatia complex, or the Ainsliaea group members.ResumenLa subfamilia Mutisioideae (74 géneros, ca. 865 especies), que comprende tres tribus, Mutisieae (43 géneros, ca. 500 especies), Nassauvieae (25 géneros, ca. 315 especies), y Stifftieae (6 géneros, 48 especies), es analizada a nivel genérico. Se estudió un total de 87 géneros que tradicionalmente fueron relacionados a Mutisioideae. Se describen e ilustran los géneros de Mutisioideae, y se proveen claves para las tribus y los géneros. Se analizan y discuten las corolas, anteras y estilos. Los caracteres del estilo (glabro, ruguloso a papiloso, las papilas cortas y redondeadas) son los más importantes para delimitar la subfamilia. La presencia y distribución de las papilas del estilo ayudan al reconocimiento de las tres tribus, aunque otros caracteres como la forma de la corola contribuyen a su definición. El polen de Nassauvieae se puede diferenciar claramente del polen de Mutisieae y Stifftieae. La morfología apoya la exclusión de Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, y Warionia, pero no la exclusión de otros taxa, por ejemplo, Hecastocleis, los miembros del complejo Gochnatia o del grupo Ainsliaea.

Gochnatia (Asteraceae, Mutisieae) and the Gochnatia complex: Taxonomic implications from morphology

Gochnatia is one of the largest genera of the tribe Mutisieae (Asteraceae) and has been traditionally characterized by its homogamous capitula with isomorphic corollas. A morphological study of Gochnatia and associated genera, i.e., Actinoseris, Chucoa, Cnicothamnus, Cyclolepis, Hyalis, lanthopappus, Nouelia, Pleiotaxis, and Wunderlichia, was carried out to evaluate the circumscription of Cochnatia and its sections, and the affinities of this complex of genera. The characters studied involve habit, leaf features (consistency, pubescence type, shape, margin, and venation), types of capitulescence, involucre features (shape, size, phyllary series, pubescence, and shape), paleae, floret features (morphology, sex, number, color of corolla, anthers, style shapes, achenial pubescence, and pappus). Analysis of these features revealed: (1) although Cochnatia is highly variable in most of the characters studied, it can be defined by this suite of features: isomorphic to subdimorphic corollas, apiculate anther appendages, and smooth style branches; (2) sections of Gochnatia needed to be re-evaluated. As result of this, two sections, i.e., sect. Discoseris and sect. Pentaphorus, are confirmed; two sections are proposed, i.e., sect. Glomerata sect. nov. and sect. Rotundifolia sect. nov.; three sections are redefined, i.e., sect. Hedraiophyllum, sect. Leucomeris, and sect. Gochnatia, while sect. Anastraphioides is formally published; and (3) the combination of apiculate anther appendages and smooth style branches is unique to Actinoseris, Cnicothamnns, Cyclolepis, Gochnatia, Hyalis, lanthopappus, and Nouelia within the Mutisieae. This group of genera is recognized here as the Gochnatia complex, with Cochnatia as the basal genus of this complex. Chucoa, Pleiotaxis, and Wunderlichia do not belong to the Gochnatia complex.

Pollen morphology and its taxonomic significance in the tribe Gochnatieae (Compositae, Gochnatioideae)

In the context of recent molecular phylogenies of the basal grades of Compositae, we investigated the utility of pollen morphology within the tribe Gochnatieae. The pollen of 64 species of Anastraphia,Cnicothamnus, Cyclolepis, Gochnatia, Pentaphorus, and Richterago was studied using light microscopy and scanning electron microscopy. In addition, three extra-Gochnatieae genera (Ianthopappus, Leucomeris, and Nouelia) were examined as they were traditionally morphologically related to members of the tribe Gochnatieae. Three of the species of Gochnatieae were examined using transmission electron microscopy. Two pollen types, and two new subtypes, have been recognized on the basis of the pollen shape, size, and exine sculpture. The pollen features of Gochnatia sect. Moquiniastrum and G. cordata are similar and distinctive within the genus and support the recently re-circumscribed section Hedraiophyllum. Within the species with echinate pollen surface, the distinctive spine length of Anastraphia supports its recent resurrection as a genus. The identity of Pentaphorus could not be supported by pollen features as was for other morphological characteristics. The pollen features shared across Cyclolepis,Ianthopappus, Leucomeris, Nouelia and Gochnatia sect. Moquiniastrum, as well as those shared by Richterago and Anastraphia could be a result of parallel evolution.

Conyza sumatrensis var. leiotheca (Compositae: Astereae), a New Combination for a Common Neotropical Weed

ABSTRACT Conyza sumatrensis is recognized as distinct from C. bonariensis and C. canadensis. Conyza albida and C. floribunda are treated as synonyms of C. sumatrensis. Conyza sumatrensis includes two varieties, and the new combination C. sumatrensis var. leiotheca is made for the nontypical variety, which is restricted to the Americas. Conyza sumatrensis var. sumatrensis is newly reported and documented in the United States; it also is found widely elsewhere in the Americas and is the sole variety occurring in the Old World.

A Phylogenetic Study in American Podocominae (Asteraceae: Astereae) Based on Morphological and Molecular Data

Abstract A molecular and morphological phylogenetic analysis of South American Podocominae is herein performed. Taxa of both South American and Australasian Podocominae as well as members of other subtribes of Astereae were included in the analyses. Sequence data from the nuclear internal transcribed spacer (ITS), and the plastid trnL–trnF intergenic spacer regions were used in the molecular analysis to assess relationships among the South American genera of Podocominae. The trnL–trnF intergenic spacer provided only six informative characters. In contrast, the ITS region was more variable. Our results showed that: 1) neither the South American genera of Podocominae nor the whole subtribe Podocominae are monophyletic; 2) South American and Australasian genera, initially placed in the subtribe Podocominae on the basis of morphological characters, show no evidence of close relationship in our phylogenetic analyses based on molecular data; 3) Our results do not confirm Podocoma in its current concept as monophyletic; 4) Asteropsis, Inulopsis, Microgyne, and Sommerfeltia form a close assemblage; 5) Microgyne is monophyletic when molecular and morphological phylogenetic analyses are performed, thus supporting previous morphology based studies; and 6) the morphological characters used to define the subtribe Podocominae are homoplastic in the context of the present morphological and DNA sequence based phylogenetic analyses.

Phylogenetic relationships in the genus Onoseris (Asteraceae, Mutisieae) inferred from morphology

Abstract Onoseris (Asteraceae, Mutisieae) is a genus of 31 species distributed from Mexico to Argentina through the Andes with its center of diversity in Peru. A phylogenetic analysis based on a detailed morphological study is provided. Urmenetea is used as the outgroup. Three most parsimonious cladograms are obtained based on the complete data set using Paup* 4.0b8. Two monophyletic groups are recognized: 1. Species with petiolate leaves, palmately veined blades with hastate base, and few-headed capitulescences, rarely thyrsoid capitulescences (O. acerifolia, O. alata, O. brasiliensis, O. cabrerae, O. castelnaeana, O. costaricensis, O. donnell-smithii, O. drakeana, O. fraterna, O. hastata, O. macbridei, O. onoseroides, O. peruviana, O. purpurea, O. sagittata, O. silvatica, and O. speciosa). 2. Species with sessile or subsessile leaves, elliptic and pinnately veined blades with attenuate base, and solitary capitula (O. albicans, O. amplexicaulis, O annua, O. chrysactinioides, O cumingii, O. gnaphalioides, O. humboldtiana, O. hyssopifolia, O. linearifolia, O. lopezii, O. minima, O. odorata, O. salicifolia, and O. weberbaueri). These monophyletic groups are recognized as subgenera Onoseris and Hipposeris respectively. Onoseris salicifolia is chosen as the lectotype of Onoseris subg. Hipposeris. Corolla polymorphism within Onoseris shows that corolla morphology alone cannot be used to distinguish between subtribes Mutisiinae and Gochnatiinae. Biogeographically, Onoseris has a continuous distribution from the Southern Andes to Northern Andes and Central America, but no individual species is distributed on both sides of the Huancabamba Zone. A group of species in subgenus Onoseris distributed in Central America and Brazil are regarded as phylogenetically derived (e.g., O. brasiliensis, O. costaricensis, O. onoseroides).

Secretory structures of leaves of Ophryosporus Meyen (Asteraceae, Eupatorieae), a genus with medicinal properties1

Abstract Ophryosporus includes ca. 40 species restricted to the Andes of Ecuador to Argentina, with a few species inhabiting Brazil. Some of its species have multiple medicinal uses such as analgesic, antisyphilitc, anti-inflammatory and antiprotozoal activity, expectorant, relief of migraine, wound healing, antiseptic and antimicrobial activities. Despite of the number of chemical studies on this genus, its secretory structures are scarcely studied. An anatomical survey of leaves shows that two types of secretory structures coexist: 1) secretory reservoirs and 2) glandular trichomes. The secretory reservoirs are schizogenous and have an uniseriate epithelium. The glandular trichomes are biseriate vesicular represented by subtypes α and β. The profuse development of secretory reservoirs in leaves of Ophryosporus could affect foraging by folivorous insect and may be the primary source of secondary metabolites with potential medicinal uses.

Revision of Microgyne (Asteraceae: Astereae), the Correct Name for Microgynella

Abstract South American Microgyne Less. is resurrected from the synonymy of Microgynella. Microgyne Cass. is a nomen nudum and therefore not validly published. The replacement generic name Microgynella, a homotypic synonym of Microgyne Less., is illegitimate and superfluous. A revision is presented for the two species of Microgyne, one herein described as new. The new species, Microgyne marchesiana, is described from Uruguay and is diagnosed by pinnatifid leaves, whitish pappus, and a thick testa. A neotype is designated for Microgyne trifurcata Less. Detailed descriptions and illustrations are provided for the two species, together with additional data on anatomy.

Guynesomia (Asteraceae: Astereae), a new genus from central Chile

Guynesomia (Asteraceae: Astereae), a new genus restricted to the western slopes of the Andes mountains in central Chile, is described. Guynesomia is a shrub characterised by raceme-like or panicle-like capitulescences, disciform capitula, alveolate receptacles, pistillate zygomorphic marginal florets with three or four short lobes, and a pappus of two series of subequal scabrid bristles. Diplostephium is the putative closest relative of Guynesomia. The new combination Guynesomia scoparia is based on Nardophyllum scoparium.

A new combination in Asteropsis (Compositae: Astereae), and a synopsis of the genus

A new combination, Asteropsis megapotamica, is made after studying specimens at Paris (P). A taxonomic revision of Asteropsis, with detailed descriptions, drawings, and images of A. megapotamica is presented. A lectotype for Neja macrocephala is designated. A discussion about generic relationships of Asteropsis and closely related genera is provided.