Lowell E. Urbatsch

Phylogeny of the Coneflowers and Relatives (Heliantheae: Asteraceae) Based on Nuclear rDNA Internal Transcribed Spacer (ITS) Sequences and Chlorplast DNA Restriction Site Data

Abstract The internal transcribed spacer (ITS) region of 18S–26S nuclear ribosomal DNA (rDNA) was sequenced in 65 taxa representing most coneflowers (i.e., species in Dracopis, Echinacea, Ratibida, and Rudbeckia) and other taxa representing 21 outgroup genera of tribe Heliantheae. Results of parsimony analysis of the rDNA dataset by itself and in combination with the cpDNA dataset uphold the hypothesis from an earlier cpDNA restriction site study that Echinacea is not closely related to the other three genera of coneflowers. The data support placement of Echinacea in subtribe Zinniinae. The remaining three coneflower genera represent a monophyletic lineage corresponding to subtribe Rudbeckiinae sensu H. Robinson. The rDNA data support two sublineages in Rudbeckia congruent with the two traditionally recognized subgenera, subg. Macrocline and subg. Rudbeckia. In subg. Macrocline, two geographic areas of diversification are indicated: southeastern and western United States. The widespread species R. laciniata is placed strongly with the western lineage of subg. Macrocline. The rDNA data support transfer of Dracopis to Rudbeckia subg. Macrocline, a relationship also supported by multiple morphological characters. The rDNA data do not confidently resolve the sister group of Rudbeckiinae from among the members of Heliantheae investigated. Multiple hypotheses are suggested for the outgroup taxa, such as expanding subtribe Zinniinae to include Echinacea and Trichocoryne, a genus previously regarded as belonging to subtribe Hymenopappinae (Heleneae or Heliantheae sensu lat.). Our findings further support expansion of subtribe Engelmanniinae to include Balsamorhiza, Borrichia, and Wyethia even though these taxa lack ray floret complexes and have fertile disc ovaries. We suggest that bioprospectors might usefully search among taxa of Zinniinae for bioactive substances similar to the immune stimulants of Echinacea. Communicating Editor: Alan Whittemore

The flavonoids of tetragonotheca (compositae)

Abstract Fifteen flavonols, five aglycones and ten glucosides were isolated from the four species of Tetragonotheca, T. repanda, T. helianthoides, T. texana and T. ludoviciana. Included among the isolated flavonols are four previously unreported 7-O-glucosides, 6-hydroxykaempferol 7-O-glucoside, 6-hydroxykaempferol 6-methyl ether 7-O-glucoside, quercetagetin 6,3′-dimethyl ether 7-O-glucoside and quercetagetin 3,6-dimethyl ether 7-O-glucoside.

The ndhF chloroplast gene detected in all vascular plant divisions

A 335-bp segment of the NADH dehydrogenase F (ndhF) gene from a representative of each nonflowering vascular plant division (Coniferophyta, Filicophyta, Ginkgophyta, Gnetophyta, Lycophyta, Psilophyta, Sphenophyta) has been sequenced and aligned with those of rice, tobacco, an orchid and a liverwort. Because ndhF is apparently absent in the genus Pinus L. (Coniferophyta), it has been speculated that this gene may be absent in the gymnosperms. However, this study suggests that the absence of the ndhF gene in Pinus may be unique and is not a general characteristic of the gymnosperms.

A Phylogenetic Analysis of the Coneflower Genera (Asteraceae: Heliantheae)

The coneflowers include the genera Dracopis, Echinacea, Ratibida, and Rudbeckia, with Rudbeckia being divided into sects. Rudbeckia, Macrocline and Laciniata. As part of a monographic study of Rudbeckia sects. Macrocline and Laciniata, relationships to other nearby Heliantheae needed to be assessed. Stuessy grouped the four coneflower genera together within the subtribe Helian- thinae. Later, Robinson erected the subtribe Rudbeckiinae to include Dracopis, Ratibida, and Rudbeckia. He removed Echinacea to the subtribe Ecliptinae on the bases of chromosome number and anatomical features and suggested a probable relationship to the genera Balsamorhiza, Helianthella, and Wyethia. In the current work, twenty-eight qualitative characters were chosen for cladistic analysis performed by the Branch and Bound algorithm in PAUP, which guarantees discovery of the most parsimonious tree. This analysis supports the historical placement of Echinacea with the coneflowers. The resulting cladogram presents the Rudbeckiinae as a monophyletic taxon with the genera of the Ecliptinae forming a group distinct from the coneflowers. The clade of the sister taxa, Dracopis and Ratibida, is related to a clade containing two distinct groups, one of Echinacea and Rudbeckia sect. Macrocline and the other of Rudbeckia sect. Rudbeckia and sect. Laciniata. Historically, Linnaeus (1753) placed the cone- flowers in the genus Rudbeckia L. At present, the coneflowers consist of approximately 35 species distributed among the genera Dracopis Cass., Echinacea Moench, Ratibida Raf., and Rudbeckia. Echinacea is a North American genus with nine species (McGregor 1968), and Ratibida, with sev- en species, occurs from southern Canada to

Phylogeny of Hinterhubera Group and Related Genera (Hinterhuberinae: Astereae) Based on the nrDNA ITS and ETS Sequences

Abstract The phylogenetic relationships of six out of seven genera from the informal Hinterhubera group (Hinterhuberinae) and nine other subtribes in tribe Astereae primarily with Southern Hemisphere distributions were studied using internal and external transcribed spacer region nuclear DNA (ITS and ETS) sequence data. Bayesian and parsimony analyses were conducted on both datasets, independently and combined. Topologies resulting from the ITS and combined data sets were highly congruent, while the ETS based phylogenies were poorly resolved, probably because the characters are fewer and less informative. The monophyly of the Hinterhubera group was not confirmed, nor were the monophyly of the subtribes Podocominae, Lagenophorinae, Grangeinae, and Asterinae as delimited by Nesom and Robinson. Instead, our results suggest a closer relationship among the taxa from similar geographic areas. Within the Hinterhubera group, the monophyly of the genera has been confirmed. Westoniella was sister to Laennecia (Podocominae), while Hinterhubera was sister to Laestadia and Blakiella. The radiate Diplostephium and Guynesomia were disparately placed in the southern hemisphere clade and not related to the other radiate genera of Hinterhuberinae. Present analyses suggest that dioecy in Aztecaster and Baccharidinae evolved independently as hypothesized by Nesom. Archibaccharis (Baccharidinae) was sister to Plagiocheilus (Grangeinae). The analyses of ITS and ETS data, and Bayesian analysis of the combined dataset, resolved Baccharidinae as non monophyletic. Constraint analyses forcing a monophyletic Baccharidinae, with Plagiocheilus sister to Archibaccharis, did not reject monophyly of the subtribe.

Phylogenetic Affinities among and within the Coneflower Genera (Asteraceae, Heliantheae), a Chloroplast DNA Analysis

For most of their taxonomic history the genera Dracopis, Echinacea, Ratibida, and Rud- beckia have been closely allied with one another. More recently an alternative classification scheme was proposed by Harold Robinson in which he established the subtribe Rudbeckiinae to accom- modate three of the genera, Dracopis, Ratibida, and Rudbeckia. He placed Echinacea in subtribe Eclip- tinae. To understand better the possible relationships among these and other genera, restriction site analysis of the chloroplast genome was undertaken. Employment of 22 enzymes resulted in detection of 643 restriction site mutations of which 249 were phylogenetically informative. Wagner parsimony generated 84 equally parsimonious trees. Bootstrap and decay analyses were used to explore the robustness of the resulting clades. Weighted parsimony analyses of the data set using weights ranging from 1.1:1.0 to 1.5:1.0 in favor of site gains generated very similar tree topologies. Chloroplast DNA data support Robinsons subtribal disposition of the coneflower genera. Among the genera of Ecliptinae investigated, two evolutionary lineages were supported. The lineage con- taining Echinacea includes Heliopsis, Helianthella, Eclipta, and Acmella. Wyethia, Balsamorhiza, Engel- mannia, Berlandiera, and Silphium are in the sister lineage. Most species of Echinacea and Rudbeckia were included in the restriction site analyses. Within these genera, some species groups were strongly supported. Low levels of variation at the species level, however, precluded detailed phy- logenetic inferences. Multiple samples within species in most cases show little chloroplast DNA variation.

Sesquiterpene lactones and lignanes from Rudbeckia species

Abstract Rudbeckia grandiflora , R. subtomentosa , R. nitida var. texana , R. scabrifolia and R. maxima were investigated for their secondary constituents. Rudbeckia subtomentosa leaves afforded the known sesquiterpene lactones 4- O -desacetylligulatine C, and ligulatine C; the flowers provided costunolide, santamarine, reynosin, the flavonol eupatolin plus a mixture of β-sitosterol and stigmasterol; the roots gave costunolide, 11,13-dihydrocostunolide, gazaniolide, isogazaniolide, tamaulipin A angelate, caryophyllene, caryophyllene oxide and β-selinene. Rudbeckia nitida var. texana , R. scabrifolia and R. maxima gave the lignanes (+)-pinoresinol dimethyl ether and yangambin. The germacrolide tamaulipin A angelate, was the major constituent of root extracts of R. grandiflora . Structure and stereochemistry of the new lactones were elucidated by spectroscopic methods. The molecular structures of gazaniolide

Coumarins from Aster praealtus

Abstract Chemical analysis of aerial parts and roots of Aster praealtus provided, besides the known coumarins umbelliferone, marmin, epoxyaurapten and 6′-hydroxy-β-cycloaurapten, four new 7- O -monoterpene ether derivatives of umbelliferone, praealtin A–D. The structures of the new compounds were established by NMR, IR, UV and mass spectral analyses and the molecular structure of praealtin A was determined by single crystal X-ray diffraction. No coumarins were detected in the following taxa: A. adnatus , A. concolor , A. dumosus x lateriflorus and A. lateriflorus , A. patens , A. spinosus , A. subulatus var. ligulatus , and A. tenuifolius . Aster adnatus provided the Δ 7 -sterol, spinasterol, and A. spinosus gave the known acetylene lachnophyllum lactone.

Sesquiterpenes from Rudbeckia grandiflora

Abstract Chemical analysis of Rudbeckia grandiflora afforded two new sesquiterpene esters, 6α-hydroxycostic acid, methyl ester and arbusculin E, methyl ester as well as two new pseudoguaianolide type sesquiterpene lactones, desacylligulatin C and rudbeckin A. Their structures were elucidated by spectroscopic methods and chemical transformations.

Guaianolides and chromenes from Calea species

Abstract Chemical analysis of Calea berteriana yielded, besides the known flavonoid acacetin and the sesquiterpene lactone calbertolide C, three new guaianolides, desacyl-8-tiglylsubcordatolide A and 8-epi-8-tiglylrupicolins A and B. C. prunifolia provided acacetin, calbertolide C, desacyl-8-tiglylsubcordatolide A, and two new chromenes, prunichromenes A and B. From C. solidaginea acacetin, heliangine, calbertolide C, 8-epi-8-tiglylrupicolin A and desacyl-8-tiglylsubcordatolide A were isolated. The structures of the new compounds were established by chemical and spectral methods.