Centaurea Taxa Research Articles

The chemical composition of the aerial parts essential oils of Centaurea erycina (Asteraceae), an endemic species of Sicily (Italy)

In the present study, the chemical composition of the essential oil from aerial parts of a very rare Centaurea species, not previously investigated, Centaurea erycina Raimondo and Bancheva, collected in Sicily, was evaluated by GC-MS. The new species, classified just twenty years ago, belongs to Centaurea cineraria group (sect. Pannophyllum Hayek, Asteraceae) and grows in an extremely limited area in the NW part of Sicily. The oil was shown to be rich of aldehydes (41.4%) and sesquiterpenes (33.4%). The main components of the essential oil were β-caryophyllene (13.4%), caryophyllene oxide (12.6%), hexanal (11.9%), and trans-2-hexenal (10.0%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to sections Pannophyllum, studied so far, was carried out.

Centaurea polyacantha and C. maroccana: the chemical composition of the aerial parts essential oils of these Centaurea species (Asteraceae) collected in Morocco

In the present study, the chemical composition of the essential oil from the aerial parts of two Centaurea species not previously investigated, C. polyacantha Willd. (sect. Seridia, Asteraceae) and C. maroccana Ball. (sect. Calcitrapa, Asteraceae), collected in Morocco, was evaluated by GC-MS. The main components of the essential oil of the first one were limonene (18.2%), β-bisabolene (11.5%), (Z)-β-farnesene (8.6%), and spathulenol (8.3%), whereas the C. maroccana essential oil, practically devoid of terpenoids, was shown to be rich in some unusual Centaurea metabolites: 1-hexadecanol (24.9%), docosane (23.7%), and 1-octadecanol (19.5%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to sections Seridia and Calcitrapa, studied so far, was performed.

The essential oil composition of the endemic plant species Centaurea vandasii and chemotaxonomy of section Phalolepis (Asteraceae)

In the present study, the chemical composition of the essential oil from aerial parts of the endemic plant species, Centaurea vandasii Velen (sect. Phalolepis, Asteraceae), collected in its locus classicus in Rhodope Mts, Bulgaria, was evaluated by GC-MS. The main components of the oil were hexadecanoic acid (18.3%), tetradecanoic acid (13.8%), caryophyllene oxide (12.1%) and germacrene D (8.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Phalolepis, studied so far, was performed. HCA (Hierarchical Cluster Analysis) and PCA (Principal Component Analyses) were used in order to demonstrate chemotaxonomical variations in the composition of the essential oils.

The essential oil composition of Centaurea immanuelis-loewii Degen growing wild in Bulgaria and chemotaxonomy of section Acrocentron

In the present study, the chemical composition of the essential oil from aerial parts of the Balkan endemic, Centaurea immanuelis-loewii Degen (sect. Acrocentron, Asteraceae), collected in Bulgaria was evaluated by GC-MS. The main components of the oil were β-caryophyllene (23.2%), germacrene D (13.7%) and caryophyllene oxide (12.4%). Furthermore, a complete literature review on the composition of the essential oils of all the other taxa of Centaurea, belonging to section Acrocentron, studied so far, was performed and the chemotaxonomical variations in the composition of the essential oils is discussed.

Typification of three Iraqi endemic taxa of Centaurea L. (Asteraceae, Cardueae)

Three Iraqi endemic taxa of Centaurea L. (Asteraceae) are typified, namely Centaurea foveolata Blakelock, C. fusiformis Blakelock, and C. longipedunculata Sch. Bip. ex Boiss.

Nomenclatural and taxonomic notes on some Centaurea taxa (Asteraceae) from southern Italy

We studied the application of the neglected name Centaurea leucolepis DC., concluding, by examination of the literature and original material, that the associated taxon is C. corensis Vals. et Filig., endemic to Campania region (southern Italy) and introduced into Sardinia. The name by Candolle is legitimate and it is here lectotypified by a specimen kept at G. In addition, after field surveys and herbarium searches, we suggest that this taxon should be considered as a subspecies of C. deusta Ten., a very polymorphic species of south-eastern Europe, proposing a new combination and providing a detailed description. In addition, we provide the validation of the name C. cineraria subsp. sirenum, endemic to Sirenuse islands (province of Salerno). Finally, a new natural hybrid within C. sect. Centaurea (C. montaltensis × C. deusta subsp. deusta) is described on the basis of the diagnosis and a specimen at PI by Michele Guadagno.

Lectotypification of two Turkish endemic taxa of Centaurea L. (Asteraceae, Cardueae, Centaureinae)

Two Turkish endemic taxa of Centaurea L. (Asteraceae) are lectotypified, namely Centaurea leptophylla (K.Koch) Tchihat. and C. paphlagonica (Bornm.) Wagenitz.

Chemical composition of the essential oil of Centaurea grinensis Reuter and Centaurea apiculata Ledeb: Growing wild in Croatia and Bulgaria, respectively and PCA analysis of subgenus Lopholoma (Cass.) Dobrocz

In the present study, the chemical composition of the essential oils from aerial parts of Centaurea grinensis Reuter (K) collected at Žuta Lova, near Senj (Croatia), and aerial parts (L1) and flowers (L2) of C. apiculata Ledeb. collected near Rebro village, near Breznik town, Znepole Region (Bulgaria), both belonging to subgenus Lopholoma (Cass.) Dobrocz, was evaluated by GC and GC-MS. The main components of K were 4-vinyl guaiacol (21.5%), hexadecanoic acid (16.2%), acetophenone (12.5%). Caryophyllene oxide (15.8%) together with sphathulenol (14.5%) and humulene epoxide II (9.4%) were recognized as the main constituent of both the aerial part (L1) and flowers (L2) of C. apiculata. Furthermore, a complete review on the composition of the essential oils of all the Centaurea taxa belonging to subgenus Lopholoma studied so far has been inserted and cluster analysis (PCA) was carried out.

Karyomorphology of Turkish species in Centaurea sections Centaurea and Phalolepis (Asteraceae) and implications for taxonomy

In this paper, 31 mostly endemic and locally distributed Turkish Centaurea taxa belonging to Centaurea and Phalolepis sections were examined in terms of their karyomorphology. The basic chromosome number for all of the studied species was concurringly determined as 9(x = 9) for both sections, excluding C. hierapolitana. We also determined tetraploid and hexaploid species in spite of many species having diploid chromosome numbers. Twelve chromosome counts are reported for the first time and most of the karyotyping analyses are described for the first time via the KAMERAM program. The karyotypes had a predominance of metacentric (m) chromosomes. However, in the karyotyping of six taxa, submetacentric (sm) chromosomes were dominant. Five quantitative asymmetric indices were used to evaluate karyological features of the species. A meaningful dendrogram was carried out to assess the karyotype-symmetry conditions and describe the karyotyping relationships between different taxa.

Karyological study on 12Centaurea(Asteraceae) species from Turkey

AbstractThe purpose of this study was to determine chromosome morphology and karyological features of 12 Centaurea L. species belonging to sections Cynaroides Boiss. ex Walp. and Phaeopappus (DC.) Boiss. from Anatolia, Turkey. The chromosome numbers were determined as 2n = 18 in all species. Karyotype analyses were made in detail for the first time for all species except Centaurea kurdica Reichardt, Centaurea fenzlii Reichardt and Centaurea amanicola Hub.-Mor. Chromosome counts of three of them (Centaurea foliosa Boiss. et Kotschy ex Boiss., Centaurea haussknechtii Boiss., Centaurea gigantea Sch. Bip. ex. Boiss.) were given for the first time. The classification of chromosomes and the lengths of long and short arm, haploid chromosome lengths, arm ratios, relative sizes and centromeric positions were represented for all species. Also, photographs of metaphase chromosomes and ideograms are given for studied Centaurea taxa. A distribution map of studied taxa is provided.

Composition of the essential oils of Centaurea aphrodisea, C. polyclada, C. athoa, C. hyalolepis and C. iberica

The genus Centaurea L. (Asteraceae) is represented in Turkey with 192 taxa, 114 of which are endemic (1–4). The present study aims at investigating the volatile compounds of two endemic Centaurea species (C. aphrodisea Boiss. and C. polyclada DC.) and three widespread (C. athoa DC., C. hyalolepis Boiss. and C. iberica Trev. ex Sprengel) Centaurea taxa from Turkey by GC and GC/MS. The analyses revealed 109 constituents, accounting between 87% and 93.4% of the oils. Major constituents of the oils of Centaurea were as follows; in C. aphrodisea: spathulenol (8.1%) and hexahydrofarnesyl acetone (7.8%); in C. athoa: caryophyllene oxide (17.1%) and heptacosane (8.1%); in C. iberica; hexadecanoic acid (27.9%) and cyclosativene (13%); in Centaurea hyalolepis: hexadecanoic acid (8.2%) and phytol (5.6%) and in C. polyclada: hexadecanoic acid (8.1%) and hexahydrofarnesyl acetone (7.1%).

On some type-specimens of «Centaurea» in Willkomm's Herbarium. 1

Abstract This is the first in a series of papers on the presence of type-specimens in Willkomm's Herbarium. This Herbarium is a 19th Century plant collection for the Mediterranean area. It was organized by Prof. H.M. Willkomm. It is kept at the Botany Institute of Coimbra University, Portugal (COI). Throughout the preliminary work leading to the creation of a database for this Herbarium, many specimen-«Typus» for taxa described by Willkomm or other botanists, are being sorted out. In this paper I report on several of these type-specimens for infrageneric taxa of Centaurea L.