Comparative capitular morphology and anatomy of Coreopsis L. and bidens L. (compositae), including a review of generic boundaries

The capitular and floral morphology and anatomy ofBidens L. andCoreopsis L. were studied. All the North American species ofCoreopsis were studied. Selected species ofBidens from North and South America andCoreopsis from South America were included. The results were compared with previous observations on African species ofBidens (incl.Coreopsis). Emphasis was given to character states of the ray florets, paleae, stylearm apices, outer phyllaries, achenes, and pollen grains. Some of the character states are unique features ofCoreopsis, e.g., globular and elongately conical receptacles, deltoid outer phyllaries, truncate and indistinctly 3–5-dentate, 3–4-lobed ray florets, narrowly spathulate paleae, subulate paleae with linear-filiform upper half, hairy and apically 3-cleft paleae, truncate, convex or shallowly conical stylearm apices with the sweeping hairs limited to the area above the stigmatic surfaces and the orbicular to circular achenes. The cylindric setaceous pappus bristles so commonly encountered inBidens are unknown inCoreopsis. The pappus bristles inCoreopsis are paleaceous but similar, though thicker ones are also found in African species ofBidens (incl.Coreopsis) with winged achenes. Twin-celled hairs (setulae) with differing degrees of wall thickness are found on the achenes ofCoreopsis sect.Pseudoagarista (Mexico and South America),Coreopsis sect.Pugiopappus (California), AfricanBidens with winged achenes (e.g.,B. prestinaria, B. macroptera) and some North AmericanBidens (e.g.,B. aristosa). Similar sclerotic parenchyma make up the achenial wings of species in both genera. These may be interpreted as homologous structures, indicating the underlying similarity of these taxa and their derivation from a common ancestral stock.     

Okanin 4′-O-diglucoside from Coreopsis petrophiloides and comments on anthochlors and evolution in Coreopsis

A new chalcone glycoside, okanin 4′-O-diglucoside, is identified from the ray florets of Coreopsis petrophiloides. The known distribution of anthochlors in Coreopsis indicates that two of the most primitive sections produce in their floral parts complex glucosides of butein (and sulfuretin). The more advanced sections synthesize the monoglucosides of okanin (marein), butein (coreospin) and lanceoletin (lanceolin) and their corresponding aurones. The co-occurrence of marein and lanceolin is thus far restricted to members of sect. Coreopsis.     

Leaf flavonoid chemistry and taxonomy of Coreopsis sect. Coreopsis

Seventeen flavonoid glycosides were isolated from the leaves of the nine species of Coreopsis sect. Coreopsis. The compounds include two flavones, four flavonols, a 6-hydroxyflavone, a 6-hydroxyflavonol, two 6-methoxyflavones, a 6-methoxyflavonol and three chalcone-aurone pairs. Chemistry distinguishes all species except C. auriculata and C. intermedia. The mean flavonoid similarity for pair-wise comparison of the four species of annuals (C. basalis, C. nuecensis, C. nuecensoides and C. wrightii) is 0.63 whereas it is 0.66 for the five perennial species (C. auriculata, C. grandiflora, C. intermedia, C. lanceolata, C. pubescens) and 0.54 for comparison of annuals with perennials. This indicates that on the average there is slightly higher flavonoid similarity among species of annuals and among species of perennials than there is between annuals and perennials. Lack of the chalcone-aurone pair coreopsin-sulfurein in perennials is the only consistent chemical difference between annuals and perennials. Leaf flavonoid chemistry supports the hypothesis that C. nuecensis and C. nuecensoides are closely related species but flavonoid data are not concordant with the hypothesis of close relationship between C. basalis and C. wrightii, intermedia, Coreopsis pubescens and C. lanceolata are considered closely related and flavonoid chemistry is concordant with this hypothesis. Coreopsis lanceolata is also viewed as closely allied to C. auriculata, but flavonoids suggest the latter species is more similar to C. intermedia. Coreopsis grandiflora is the only perennial species lacking flavonols and has the fewest number of compounds of any species in the section; chemical data support the view that C. grandiflora is quite distinct from other perennial species of sect. Coreopsis.     

Revision of the genus Clibadium (Asteraceae, Heliantheae)

Clibadium L. (Asteraceae, Heliantheae) is a genus of 29 species distributed throughout latin America, from Mexico to Peru, and in the West Indies, with high numbers of species in Costa Rica, Colombia, and Ecuador.Clibadium includes shrubs and small trees; usually with loosely aggregated capitula; herbaceous phyllaries arranged in 1–5 series; receptacles usually paleaceous throughout; corollas of pistillate florets 2–4-lobed; corollas of the staminate florets 4–5-lobed; purple to black anthers; and chromosome numbers alln=16. Two sections of species previously recognized are here considered as subgenera (subg.Paleata and subg.Clibadium) containing two and four sections, respectively.Clibadium subg.Paleata contains five species distributed in sects.Eggersia (3 spp.) andTrixidium (2 spp.), and subg.Clibadium has 24 species distributed among sects.Clibadium (6 spp.),Glomerata (9 spp.),Grandifolia (5 spp.), andOswalda (4 spp.).     

Flavonoids and phylogenetic reconstruction

Flavonoids have been used successfully for interpreting evolutionary relationships in many groups of angiosperms. These interpretations often have been presented in narrative fashion without specific indications of the kinds of relationships expressed. In this paper a method of phylogeny reconstruction with flavonoid data showing cladistic, patristic, and phenetic relationships is presented. Such a phylogram contains maximal information about flavonoid evolution. As an example, relationships in the North American species ofCoreopsis (Compositae), containing 46 species in 11 sections, are analyzed by this approach. A phylogeny of sections of the genus from previous morphological, chromosomal and hybridization data is compared with that from data on anthochlors (chalcones and aurones). Strong correspondence of these evolutionary interpretations gives support to the hypothesized evolutionary trends within the group.     

Isozymes of coreopsis section Calliopsis (Compositae): Genetic variation within and divergence among the species

Enzyme electrophoresis was employed to examine genetic variation within and among the three diploid (n=12) species comprisingCoreopsis sectionCalliopsis: C. leavenworthii, C. paludosa andC. tinctoria. Twelve enzymes specified by 20 genes were included, and those isozymes localized in the plastids were identified for several of the enzymes. Mean genetic identities calculated for pair-wise comparisons of 22 populations (four ofC. leavenworthii, one forC. paludosa, and 17 ofC. tinctoria) reveal no genetic differentiation betweenC. leavenworthii andC. tinctoria, whereasC. paludosa exhibits lowered values with the other two taxa. These results are in general agreement with concepts of relationships inferred from morphological and biosystematic data. That is,C. paludosa has been viewed as more distinct fromC. leavenworthii andC. tinctoria than the latter two are from each other. The high similarity betweenC. leavenworthii andC. tinctoria is somewhat unexpected, however, given the several morphological features that serve consistently to distinguish them.     

The phytomelanin layer in traditional members of Bidens and Coreopsis and phylogeny of the Coreopsideae (Compositae)

The phytomelanin layer on the pericarp of cypselae (achenes) of many members of traditional Bidens and Coreopsis, both considered polyphyletic, was studied with the help of scanning electron (SEM) and light (LM) microscopes. It is found to be more prominent in taxa kept within Bidens than in Coreopsis. The black ‘peg‐like’ phytomelanin found in traditional members of Bidens is also found in some members of Coreopsis. Some traditional members of Coreopsis display distinctive pericarp morphology but lack phytomelanin. The pericarp in Bidens is striated, i.e. it is interrupted by longitudinal bands of parenchyma through which the embryo emerges during seed germination. No striation was found in cypselae of traditional Coreopsis. Emergence of the seed in taxa with this type of pericarp morphology is observed to be by rupturing the carpel wall along the sutures. Characteristic morphology of the phytomelanin layer and other cellular secretions on the pericarp in representative species of these genera and segregates as well as the probable adaptive value of this layer and that of the parenchyma is discussed. Coreopsis sect. Tuckermannia (Nutt.) Blake, C. sect. Pugiopappus (A. Gray) Blake, and C. sect. Euleptosyne (A. Gray) Blake, are elevated to the genus Leptosyne DC., while Coreopsis sect. Electra (DC.) Blake is returned to Electra DC. A key to the segregate genera and the remaining sections of Coreopsis as well as new combinations and synonyms are provided.     

Bisabolene derivatives and acetylenic compounds from peruvian Coreopsis species

The investigation of three Peruvian Coreopsis species afforded, in addition to compounds isolated previously from this genus, two new tetraynenes and five sesquiterpenes all related to perezone, including a tricyclic ketone with a cedrane skeleton closely related to pipitzol. The structure were elucidated by spectroscopic methods.     

The occurrence of C4 species in the genusRhynchospora and its significance in kranz anatomy of the cyperaceae

Rhynchospora rubra was found to have a low CO₂ compensation point, high δ¹³C value, Kranz leaf anatomy, starch present in the bundle sheath cells and narrow interveinal distance. These observations suggest thatR. rubra is a C₄ plant. A further anatomical survey revealed seven otherRhynchospora species presumably having the C₄ photosynthetic pathway. In the family Cypraceae C₄ plants therefore occur in the tribe Rhynchosporeae as well as in the Scirpeae and Cypereae. The C₄ species ofRhynchospora have a normal Kranz type of leaf anatomy, although the C₄ species ofCyperus andFimbristylis presently known have an abnormal one in which the mestome sheath without chloroplasts is interposed between the Kranz tissue and the rest of the chlorenchyma. Thus inRhynchospora the Kranz tissue is in direct contact with the rest of the chlorenchyma, and it is suggested that the Kranz tissue may be homologous with the mestome sheath.     

Stem aerenchyma as a character separating hymenachne and sacciolepis (Gramineae,Panicoideae)

Hymenachne andSacciolepis, two closely related tropical genera, have been distinguished by the saccate second glume in the latter, a trait lacking in the former. It is difficult to assign certain species to genus on this basis alone. A survey of both genera showed that aerenchyma fills the stem pith region ofHymenachne species but is absent or nearly so fromSacciolepis species. The leaf epidermis ofHymenachne bears prickle cells, which have not been reported fromSacciolepis. Additional anatomical details are given forH. amplexicaulis.     

CHLOROPLAST DNA RESTRICTION SITE VARIATION AND THE PHYLOGENY OF COREOPSIS SECTION COREOPSIS (ASTERACEAE)

Restriction site variation in chloroplast DNAs (cpDNAs) of Coreopsis section Coreopsis was employed to assess divergence and phylogenetic relationships among the nine species of the section. A total of fourteen restriction site mutations and one length mutation was detected. Cladistic analysis of the cpDNA data produced a phylogeny that is different in several respects from previous hypotheses. CpDNA mutations divide the section into two groups, with the two perennial species C. auriculata and C. pubescens lacking any derived restriction site changes. The other seven species are united by five synapomorphic restriction site mutations and the one length mutation. These seven species fall into three unresolved clades consisting of 1) the remaining three perennial species, C. grandiflora, C. intermedia, and C. lanceolata; 2) three annual species, C. basalis, C. nuecensoides, and C. nuecensis; and 3) the remaining annual, C. wrightii. The cpDNA data suggest that, although the perennial habit is primitive within the section, the annual species of section Coreopsis have likely not originated from an extant perennial species. The estimated proportion of nucleotide differences per site (given as 100p) for the cpDNAs of species in the section ranges from 0.00 to 0.20, which is comparable to or lower than values reported for other congeneric species. The low level of cpDNA divergence is concordant with other data, including cross compatibility, interfertility and allozymes, in suggesting that species of the section are not highly divergent genetically.     

Leaf flavonoid chemistry of Coreopsis (Compositae) section Palmatae

Examination of leaf flavonoids of all taxa ofCoreopsis sectionPalmatae revealed that most members synthesize an array of common flavone (mostly luteolin and apigenin) glycosides. Each diploid species or diploid member of a species is characterized by a particular ensemble of compounds. These taxa includeC. major, C. verticillata, C. pulchra, C. palmata, andC. tripteris. The latter species differs from all other taxa in producing flavonol (kaempferol and quercetin) glycosides and what appear to be 6-oxygenated compounds. Tetraploids ofC. verticillata exhibit the same flavonoids as diploid members of the species, thus flavonoid chemistry supports the hypothesis that they originated from diploids within the species. Certain populations of hexaploid and octoploidC. major are similar chemically to diploids, suggesting they also originated as intraspeciflc polyploids. Other populations of these polyploids exhibit a flavonoid profile which differs from the profile of the diploids, and this profile is nearly identical to the octoploidCoreopsis × delphinifolia. The latter taxon has been viewed by Smith (1976) and Mueller (1974) as an interspecific hybrid betweenC. verticillata andC. major and/orC. tripteris. Species-specific compounds from the former species occur inC. × delphinifolia but no compounds unique to either of the latter two species are discernable. Flavonoid chemistry is not useful in ascertaining whether either or both species have been involved withC. verticillata in producing plants referable toC. × delphinifolia. There is morphological intergradation between octoploidC. major andC. × delphinifolia, and all plants not appearing to be “pure”C. major exhibit a flavonoid chemistry likeC. × delphinifolia. All plants of sectionPalmatae considered to be alloploids (includingC. × delphinifolia) produce the same array of leaf flavonoids, including several “novel” compounds not expressed in the putative parental taxa. Two of the “novel” flavonoids are present in the geographically restricted diploidC. pulchra. The systematic and phylogentic significance of this is not readily apparent.     

A note onSaissetia oleae and its natural enemies in Iran

A cursory survey made in the Rudbar area and on the Caspian coast in Iran revealed that two species ofChalcidoidea, five species of Coccinellids, one Nitidulid and one Neuropteron attackedSaissetia oleae (Ol.). Of thesePullus sp. andScymnus sp. (Coccinellidae) were common and appeared to be important biological control agents.     

DNA restriction enzyme fragment polymorphism as a tool for rapid differentiation ofAspergillus flavus fromAspergillus oryzae

Aspergillus flavus andAspergillus oryzae are difficult to differentiate using standard morphologically based characteristics. This survey, using several restriction enzymes, showed thatSmaI digestions of total DNA could be used to differentiate these two closely related species ofAspergillus. A different electrophoretic pattern was associated with each of the two species, while within a species the pattern remained constant. CsCl banding of DNA from one isolate of each species indicated the DNA that produced the species-specific pattern was associated with the nuclear DNA fraction.     

Transfer of coreopsis congregata (Compositae: Heliantheae) to coreocarpus

Coreopsis congregata Blake is out of place in the genusCoreopsis. Its achene morphology, pubescence, leaf cutting and geographical range suggest that it would be better treated in the genusCoreocarpus (Coreocarpus congregatus) and that transfer is proposed.     

Systematics of the genusCandida Berkhout: Proton magnetic resonance spectra of the mannose-containing polysaccharides of some further species ofCandida as an aid in classification

The proton magnetic resonance spectra of the mannose-containing polysaccharides of 48Candida species were determined. Two other species formed heteropolymers for which p.m.r. spectra could not be obtained. The species were grouped as follows: 17 species formed mannose-containing polysaccharides with spectra like those ofHansenula anomala, Pichia farinosa, Pichia membranaefaciens orPichia robertsii mannans; 12, like those ofMetschnikowia andDebaryomyces mannans; 6, like those of mannans ofSaccharomyces species; 4, like that ofTorulopsis bombicola mannan; and 4, like those ofCandida obtusa andCandida tepae polysaccharides. Five formed mannans whose spectra were unlike those of the mannans of any other yeast species examined.     

STUDIES ON SOME SPECIES OFARTHOTHELIUMOCCURRING IN THE WESTERN MEDITERRANEAN

We present a survey of the six known species ofArthotheliumoccurring in the western Mediterranean. The oceanicA. lirellans, which may occur in the study area, is included for comparison;A. taediosoidesis described as new and a key to all species is given.Arthotheliumas understood today is composed of more-or-less distinct natural groups of species, some of them being compared here. Representatives of theA. sardoumgroup are related to species of theArthonia radiataorA. galactitesgroup on the basis of anatomical characters of the ascomata.