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Taxonomic complexity in wild potatoes (SolanumL. sect. PetotaDumort.) has led to widely conflicting treatments. Solanumser. PiuranaHawkes is one of 21 series recognized in S. sect. Petotain the latest comprehensive taxonomic treatment by Hawkes in 1990. They are distributed from southern Colombia south through Ecuador to central Peru. The taxonomic limits of the series and validity of its constituent species were not resolved with previous studies. In the present study, a set of five conserved orthologous DNA markers (cos II) with 5342 bp of aligned length were used to infer the phylogeny of putative members of Solanumser. Piuranaand outgroups. The results agreed with a three-clade topology shown by previous studies within S. sect. Petota. Solanumser. Piuranais expanded to include some species formerly included in S. sers. Conicibaccata, Cuneoalata, Ingaefolia, Olmosiana, Simplicissima, Tuberosaand Yungasensa. This expanded group is supported morphologically by the presence of moniliform tubers and coriaceous leaves in most species.

Solanum berthaultiiand S. tarijenseare two wild potato (sect. Petota) species distributed from Bolivia to northern Argentina. All authors have accepted them as good species since their publication in 1944, but they have been hypothesized to hybridize extensively with each other and with other species, despite their classification into different series and superseries by some authors. This study is a molecular counterpart (AFLPs, plastid DNA restriction site data, survey of a plastid DNA deletion) to a prior morphological study of these two species. AFLP data show weak support for separate species status for some accessions, but with many exceptions. In agreement with the morphological results we place S. tarijenseinto synonymy of S. berthaultii, and use herbarium specimen data for a taxonomic treatment to include a description, synonymy, and mapping of all accessions. We show similar taxonomic problems in sect. Petotaand suggest that there will be a continuing trend of reduction of names in wild potatoes.

Wild tomatoes (Solanumsection Lycopersicon) are native to western South America. The delimitation and relationships of tomato species have differed widely depending upon whether morphological or biological species concepts are considered more important. Molecular data from mitochondrial, nuclear, and chloroplast DNA restriction fragment length polymorphisms (RFLPs), nuclear microsatellites, isozymes, and gene sequences of internal transcribed spacers of nuclear ribosomal DNA (ITS; multiple­copy), the single­copy nuclear encoded Granule­bound Starch Synthase gene (GBSSI or waxy), and morphology, have been used to examine hypotheses of species relationships. This study is a companion to the previous GBSSI gene sequence study and to the morphological study of relationships of all ten wild tomato species (including the recently described S. galapagense), with a concentration on the most widespread and variable species S. peruvianums. l. These new AFLP data are largely concordant with the GBSSI and morphological data and in general support the species outlined in the latest treatment by C. M. Rick, but demonstrate the distinct nature of northern and southern Peruvian populations of S. peruvianum, and suggest that their taxonomy needs revision. Solanum ochranthumis supported as sister to wild tomatoes, and S. habrochaitesand S. pennelliireside in a basal polytomy in the tomato clade.

Many morphological features of the heads of Compositae are systematically useful. Receptacular bracts (pales or paleae) are of particular significance taxonomically. These structures occur in nine of the 13 recognized tribes (absent in Arctoteae, Calenduleae, Senecioneae and Tageteae), with the greatest concentration in the Anthemideae, Heliantheae, and Inuleae. Because the Heliantheae contain the broadest diversity of pale types, the adaptive significance of these features within this tribe deserves special emphasis. Certain subtribes of the Heliantheae are characterized by distinctive types of pales, such as flattened with orange‐brown lines in the Coreopsidinae, pales subtending only the outer series of disc florets in the Madiinae, or their complete absence in the Bahiinae. Of the five principal factors affecting the evolution of features of heads in the family, viz., protection, dispersal, pollination, breeding systems, and seed germination, the former two are most likely the most important selective forces in the evolution of pales. Dispersal functions of pales include attachment or close envelopment of the achene by the pales with removal of the entire unit by wind from the head, conduplicate pales serving as chutes for release of unattached achenes, and brightly colored, fleshy pales being attractive to animals. Protective functions occur against predators and environmental extremes, and occur in bud, anthesis, and mature fruiting stages. Pales function during anthesis to protect ovaries and achenes from apical and lateral insect attack. The particular variations of the pales depend on the associated structures of the heads and breeding systems. In a phylogenetic context, the large and sometimes foliose pales of the Heliantheae seem best interpreted as adaptations for protection of large achenes and not necessarily as reflections of a primitive condition within the family.

Spooner, D. M. & Berg, R. G. van den: Species limits and hypotheses of hybridization of Solanum berthaultiiHawkes and S. tarijenseHawkes: morphological data. ‐ Taxon41: 685‐700. 1992. ‐ ISSN 0040‐0262. Solanum berthaultiiHawkes and S. tarijenseHawkes have been recognized as distinct species by all authors since their description in 1944. Some authors have considered them as sister species, but more recently they have been treated as unrelated species belonging to separate superseries. Hypotheses of species boundaries and hybridization have been examined using principal components analysis, stepwise discriminant analysis, canonical discriminant analysis, and one‐way analysis of variance. 25 morphological characters measured on four individuals from each of 84 living accessions from throughout their natural range were analysed. Extensive intra‐accession, intraspecific, and interspecific variability have been found in many characters, including those previously given great taxonomic weight. 9 characters show no statistically significant differences between species or putative interspecific hybrids. The remaining 16 characters show statistically significant differences between species and putative hybrids, but show so much variability that repeatable identifications of some accessions would require the use of population samples. The data suggest the possibility that the two species should be treated as one. Other currently‐recognized species within S. sect. Petotamay need to be reevaluated for synonymy. The results also question the hypotheses of extensive hybridization, interpretation of series designations, and the phylogenetic interpretation of corolla shape at the superseries level in S. sect. Petota.