Benoît Loeuille

Taxonomic novelties in Eremanthus (Compositae: Vernonieae) from Brazil

SummaryThe description and illustration of a new species of Eremanthus (Asteraceae: Vernonieae), E. brevifolius, endemic to Minas Gerais State, is presented and its affinities assessed. E. graciellae and E. pohlii are newly synonymised under E. capitatus, and E. seidelii under E. elaeagnus.

Systematics and Evolution of Syncephaly in American Vernonieae (Asteraceae) with Emphasis on the Brazilian Subtribe Lychnophorinae

Abstract— A phylogenetic hypothesis of American Vernonieae based on three molecular regions (ITS, ndhF, rpl32-trnL) and on a morphological dataset reveals the existence of four main lineages. Three of these lineages correspond, with a few adjustments, to subtribes Chrestinae, Lychnophorinae, and Vernoniinae. The fourth lineage, which has never been recognized at a taxonomic rank due to the lack of morphological characterization, is mainly composed of taxa usually included in Lepidaploinae and Elephantopinae as well as a number of genera traditionally placed in other subtribes (Chrestinae, Piptocarphinae, and Vernoniinae). The relationships between these lineages are still not satisfactorily resolved. In order to keep the Lychnophorinae monophyletic, two small subtribes (Centratherinae, Sipolisiinae) and three monotypic genera (Albertinia, Blanchetia, and Gorceixia) have to be transferred to Lychnophorinae, which has the presence of heliangolide in aerial parts as a synapomorphy. Even though syncephaly has been historically used to delimit the subtribe Lychnophorinae, our results show that this character probably appeared independently three or four times in the evolution of American Vernonieae. The formation of the syncephalium, in each case, seems to be related to different biological functions: attractive (Chrestinae), disseminative (Rolandrinae), or protective and, to a lesser extent, attractive (Lychnophorinae).

A Phylogenetic Analysis of Lychnophorinae (Asteraceae: Vernonieae) Based on Molecular and Morphological Data

Abstract The subtribe Lychnophorinae (Asteraceae: Vernonieae) comprises approximately 100 species and 18 genera distributed mostly in the Cerrado Domain of the Brazilian Central Plateau. Phylogenetic analyses of Lychnophorinae based on four molecular regions (ETS, ITS, ndhF, rpl32-trnL) and a morphological dataset were performed, aiming to delimit monophyletic genera, to confirm or refute the generic assignment of several species, to achieve a better understanding of the relationships between the genera, and to identify morphological characters and synapomorphies for major clades within the subtribe. Our analyses recovered several clades that represent currently recognized genera or genera that have been recognized in the past. All clades recovered are characterized by a combination of morphological characters. However, Lychnophora (35 species), the richest genus of the subtribe, emerged as polyphyletic. Albertinia, Blanchetia and Gorceixia were the first lineages to diversify, whereas Eremanthus plus Lychnophora sensu stricto emerged as the most derived clade. Relationships among other clades remained partially unresolved. Some incongruence in the placement of species of Eremanthus, Paralychnophora, and Piptolepis in the nuclear and chloroplast phytogenies provided additional evidence for the occurrence of two putative intergeneric hybrids in the wild. Biogeographic reconstruction suggests that the diversification and expansion range of most Lychnophorinae clades in the campos rupestres, from an ancestor in tropical seasonl forests, occurred previously to the conquest of the cerrado s. s. areas performed by only a few clades.

Functional groups in Lychnophorinae (Asteraceae: Vernonieae) based on morphological and anatomical traits

The Lychnophorinae subtribe (Asteraceae: Vernonieae) occurs mainly on the Central Brazilian Plateau, especially in areas characterised by intense solar radiation, large daily temperature fluctuations, water scarcity during autumn and winter, and frequent fire. However, a few species of Lychnophorinae, such as Blanchetia heterotricha DC., are not restricted to the Cerrado Domain, but can live in open and humid areas of borders of the Atlantic Forest. To understand the mechanisms of Lychnophorinae adaptation to these environmental conditions, habit, leaf and stem functional traits from 12 species were analysed. Leaf and stem samples were processed and stained using standard plant-anatomy methodology. A comparative analysis of functional groups was performed by principal coordinates analysis, which was applied to two matrices of 30 qualitative and five quantitative traits. The multivariate analysis based on qualitative traits highlighted the following four functional types that might be linked to ecological conditions: Group I adapted at open and humid areas of borders of the Atlantic Forest; Group II, with features mostly related to foggy habitats; Group III, exhibiting traits quite adapted to the seasonally dry and variable conditions of the campos rupestres; and Group IV, showing the most specialised morphological and anatomical traits, which might be related to the extreme conditions of the campos rupestres.

The Lucilia group (Asteraceae, Gnaphalieae): phylogenetic and taxonomic considerations based on molecular and morphological evidence

The Lucilia group sensu Anderberg and Freire comprises nine South American genera: Belloa, Berroa, Chevreulia, Cuatrecasasiella, Facelis, Gamochaetopsis, Jalcophila, Lucilia and Luciliocline. The aims of this contribution were, using DNA sequences from plastid (rpl32-trnL, trnL-F) and nuclear (ITS and ETS) markers, together with morphological characters, to test the monophyly of the Lucilia group and provide new insight into generic circumscriptions. Our studies, including a broad taxon sampling of Gnaphalieae species, suggest that the Lucilia group is paraphyletic, since Antennaria, Chionolaena, Gamochaeta, Loricaria, Micropsis, Mniodes and Stuckertiella are all nested within the Lucilia group. Morphology and molecular analyses combined showed that the traditional generic circumscription of most of the genera (e.g., Berroa, Chevreulia, Chionolaena, Cuatrecasasiella, Facelis, Jalcophila and Micropsis) correlates with the inferred phylogenetic relationships. Conversely, Lucilia and Luciliocline are non-monophyletic. Lucilia is nested in a clade with Berroa, Facelis and Micropsis. Luciliocline is strongly embedded within the clade Belloa pp + Mniodes. Our results are consistent with Dillon’s study that considered Belloa as a montotypic genus (B. chilensis). Luciliocline and the remaining species of Belloa are accommodated in the genus Mniodes, and the necessary combinations are proposed for the expanded Mniodes. All the analyses showed that the monotypic genera Stuckertiella and Gamochaetopsis are in a well-supported clade nested within Gamochaeta, which implies that taxonomic changes are required also for these genera. Internal relationships in the group and the key morphological characters used in the taxonomy of the group, as well as incongruences found between morphological and molecular analyses, are discussed.

Two New Species of Heterocoma (Asteraceae: Vernonieae) and a Broadened Concept of the Genus

Abstract A new concept of the genus Heterocoma is presented based on morphological and anatomical evidence. The genus is characterized by the combination of foliose subinvolucral bracts, fimbrillate or paleaceous receptacles, glabrous cypselae, and a caducous biseriate pappus (at least the inner series). A putative synapomorphy of the genus is the presence of phytomelanin in the cypselae walls. The monotypic genera Bishopalea, Sipolisia, and Xerxes are synonymized under Heterocoma with the following new combinations: Heterocoma ekmaniana, Heterocoma erecta, and Heterocoma lanuginosa. Two new species, Heterocoma gracilis and Heterocoma robinsoniana, are described and illustrated. The genus is endemic to the campos rupestres of the Brazilian Central Plateau. A key to the six species recognized in Heterocoma is provided.

Pollen morphology of the genus Eremanthus Less. (Vernonieae, Asteraceae)

In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae), and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits.

Pollen morphology of the genus Paralychnophora (Vernonieae–Asteraceae)

Paralychnophora is an exclusively Brazilian genus that has few species and a confusing taxonomy. The current study aims to help us better understand this genus by analysing pollen grains from six Paralychnophora species. The pollen grains were acetolysed, analysed and photomicrographed under light microscopy. They were not acetolysed for the scanning electron microscopy analysis. Features such as shape, size, exine constitution and aperture were investigated. The species were separated in a pollen key, and their features were of great diagnostic value for the genus. The ornamentation pattern allowed separating P. patriciana from P. reflexoauriculata, and it grouped the other taxa. P. atkinsiae distinguished itself by the polar area index (PAI) size. P. bicolor, P. harley and P. glaziouana were easily separated from each other when other features such as size, shape, distance between the spines and aperture dimensions were analysed together.

The Lychnophora granmogolensis (Asteraceae—Vernonieae) Species Complex: Two New Species and Comments on the Identity of Lychnophora granmogolensis

Abstract Lychnophora rupestris and Lychnophora nanuzae are two new endemic species from quartzitic, rocky-field vegetation in Brazil. These new species are described and illustrated, and their affinities discussed. They are similar to L. granmogolensis, suggesting the definition of a species complex. The L. granmogolensis species complex can be recognized by imbricate leaves, ericoid, revolute margins, pungent apex with mucron, 1–3 flowers per capitulum, and outer pappus series free or partially fused. Lychnophora granmogolensis is a poorly known species from the Diamantina plateau in northern Minas Gerais State, and Chapada Diamantina (Bahia) in the Espinhaço Mountain Range. To clarify the application of the name L. granmogolensis, that species is also described and illustrated, and affinities are discussed.

A new species of Paralychnophora (Asteraceae: Vernonieae), and comments on the identity of Paralychnophora bicolor

The type of Paralychnophora bicolor was found to represent another species recently described as P. santosii. The misapplication of the name P. bicolor is reviewed. Also, a new species is here proposed, P. glaziouana, for plants previously identified as P. bicolor, since the only available name, P. schwackei, is an illegitimate combination. A key to Paralychnophora is given.