A new species of Coreopsis (Compositae — Heliantheae) from Mexico

Coreopsis crawfordii is described and illustrated. It is also compared with themorphologically similar species, C. pringlei and C. rudis , also from Mexico, and a key to all the species of Coreopsis known from Mexico is provided.     

A new species of Bidens (Compositae) from Mexico

Bidens longistyla, an annual species with a square stem and yellow rays, known only from the States of Nuevo León and Coahuila, Mexico, is described as new.     

Verbesina barrancae (Compositae, Heliantheae), a new species from Jalisco, Mexico

Verbesina barrancae, a new species of Compositae (Heliantheae) from Jalisco, México, is described and illustrated. It is morphologically similar toVerbesina crocata but differs in characteristics of inflorescence, anthers, and achenes as well as in form of pollen, size and number of spinules, size of colpus transversalis, and index of polar area.     

A new species of Polymnia (Compositae: Heliantheae) from Mexico

Polymnia mcvaughii from Jalisco, Mexico, is described as new. This herbaceous species appears to belong in the mainstream of evolution within the genus. It exhibits marked affinities to several species, but most closely resemblesP. oaxacana Schultz-Bip. Illustrations of important features are included, along with a list of key characteristics.     

A new species of Viguiera (Asteraceae: Heliantheae) from Mexico

AlthoughViguiera hidalgoana, a new species from Hidalgo, Mexico, bears a superficial resemblance toV. dentata, it is clearly related to certain woody species of seriesGrammatoglossae.     

A new species of flourensia (Asteraceae: Heliantheae) from northern Peru

Flourensia cajabambensis, a new species from northern Peru, is described and illustrated, and its relationships are discussed. A key to the Peruvian species ofFlourensia is presented.     

Five new species of calea (Compositae: Heliantheae) from planaltine Brazil

Described from the Planalto of Brazil are:Calea quadrifolia, C. heteropappa, andC. abbreviata of sectionMeyeria,C. intermedia of sectionLemmatium, andC. lutea of sectionCalea. The relationships of each are discussed and a key to the nearest relatives of each is provided. Additionally, all butC. intermedia are illustrated.     

A new species of Verbesina (Asteraceae: Heliantheae) from northeastern Mexico

Verbesina lanulosa is described as a new species from the Mexican state of Nuevo Leon. This species is compared with V. chihuahuensis and V. suberosa, and mainly differs by its leaf shape, petiole form, and pubescence of the stems, leaves, and inflorescences. An illustration is included.     

Six new species of melampodium (compositae: Heliantheae) from Mexico and Central America

Six species of the genusMelampodium are described as new:M. glabribracteatum, M. nayaritense, andM. pilosum (sect.Melampodium);M. costaricense, M. nutans, andM. sinaloense (sect.Zarabellia). Chromosome numbers forM. nutans andM. pilosum are reported asn = 11 andn = 10 respectively     

Sesquiterpene and polyacetylene profile of the Bidens pilosa complex (Asteraceae: Heliantheae) from Southeast of Brazil

The pantropical weed Bidens pilosa (Asteraceae) is a species with several taxonomic problems. Recently it has been shown to be a complex of different species. To shed light on this problem in Brazil, dichloromethane extract of leaves of several populations corresponding to three proposed species for the complex in southeastern Brazil (B. pilosa, Bidens alba and Bidens subalternans) were analyzed by GC–MS. Twenty-four substances were detected, of which four resemble polyacetylenes, the others sesquiterpenes. Five sesquiterpenes tentatively identified as E-caryophyllene, α-humulene, germacrene-D, bicyclogermacrene and α-muurolene were found in all three Bidens species. The polyacetylene phenylhepta-1,3,5-triyne was identified only in B. alba. Multivariate analysis (cluster and principal component analyses) separated the three entities, suggesting that these compounds could represent a useful tool to distinguish species in the B. pilosa complex.     

Generic relationships of Oparanthus and Petrobium,especially with reference to Bidens (Compositae,Heliantheae, Coreopsidinae)

Oparanthus with two species from the Tubuai Islands of the South Pacific Ocean and the monotypicPetrobium from St. Helena in the South Atlantic are judged to belong more properly withinBidens. Comparisons of diagnostic morphological features are provided, and the necessary combinations are made, includingBidens rapensis (F. Brown) Stuessy andB. tubuaiensis (F. Brown) Stuessy.     

New species and combinations in Sabazia (Heliantheae,Galinoginae)

The genusSabazia is expanded to include the genusTricarpha, Calea palmeri, and several newly described taxa,S. tridacoides var.tridacoides and var.latifolia, S. palmeri var.lancifolia, andS. longiradiata. Comparative studies of several morphological features suggest thatSabazia is most clearly related toSelloa andGalinsoga. Karyological data reinforce this observation: inSelloa andGalinsoga x = 8 whereas inSabazia x = 4 andn = 4, 8, 16, or 24. Several species ofCalea are very similar toSabazia in floral features and may be of close phyletic affinity, but most species ofCalea differ conspicuously, suggesting more remote relationships. Other taxa in the Galinsoginae apparently fairly closely allied toSabazia includeOteiza andTridax.

     

Morphometric analyses and new taxonomic circumscription of South American species of Flourensia (Asteraceae,Heliantheae, Enceliinae)

Flourensia (Asteraceae, Heliantheae, Enceliinae) is an amphitropical genus of resinous subshrubs, shrubs and small trees with 13 North American and 20 South American species among which disagreement on the species limits of some members still exists. To resolve the taxonomy of the South American taxa, we carried out a combination of clustering (Ward's method with Gower distance coefficient) and ordination analyses (Principal Coordinate Analyses) based on 34 vegetative and reproductive characters scored from herbarium material, including types. Based on the results, we recognize 12 South American species: F. angustifolia, F. cajabambensis, F. fiebrigii, F. heterolepis, F. hirtissima, F. macrophylla, F. niederleinii; F. peruviana, F. polycephala, F. thurifera, F. tortuosa and F. suffrutescens. A number of species are placed in synonymy: Flourensia blakeana and F. hirta are synonymized under the name F. fiebrigii; Flourensia campestris, F. leptopoda, F. oolepis and F. riparia are synonymized under F. thurifera; Flourensia macroligulata is synonymized under F. tortuosa, and Flourensia polyclada is synonymized under F. suffrutescens. A taxonomic treatment of four redefined species as well as a key and distribution maps to all South American Flourensia species are provided.     

Bauhinia chrysophylla, a new species from Thailand (Leguminosae–Caesalpinioideae)

A new species of Bauhinia from Peninsular Thailand is described as B. chrysophylla. It appears to be endemic to an isolated mountain and must be regarded as a rare and endangered species. Its pollen morphology is studied and its relationships discussed.     

Stuessya (Asteraceae: Heliantheae), a new genus from southcentral Mexico

Stuessya, a new genus from the Pacific slopes of southcentral Mexico is described. It is comprised of three species:S. apiculata, previously assigned to the genusViguiera;S. perennans, the generotype; andS. michoacana. The latter two taxa are previously undescribed. The genus is characterized by its urceolate, sclerified (at maturity) involucre. Chromosome counts of2n = 34 are reported forS. perennans. Relationships are problematical, but are reckoned to be somewhere betweenAldama andViguiera.     

A new Madia of sect. Anisocarpus (Compositae: Heliantheae) from Trinity County,California

A new annual species ofMadia sect.Anisocarpus,Madia doris-nilesiae, from the serpentine soils of western Trinity County, California is described, illustrated, and compared to the other annual members of the section. On the basis of floral and fruit morphologies the annual members of the section can be divided into two geographical units.Madia dorisnilesiae is unique in that it has a combination of these characters.