Thlaspideae is an Old World tribe of Brassicaceae centered in SW Asia. Thirty–seven of 42 species (ca. 88%) in 13 genera of the tribe were analyzed using nuclear ITS and chloroplast trnL–F markers in a family–wide context. Both single–marker and concatenated phylogenies corroborated Thlaspideae as a well–supported monophyletic clade. With the exception of polyphyletic Alliaria and Parlatoria and paraphyletic Thlaspi and Didymophysa, the remaining genera were monophyletic. Alliaria petiolata comprised diploid and hexaploid populations in two well–resolved clades. The non–weedy diploid and hexaploid populations are restricted to SW Asia, and together with diploid A. taurica (formerly P. taurica), formed a sister clade to well–resolved Sobolewskia (3 spp.) and P. rostrata (now treated as the new monospecific genus Lysakia) clades. By contrast, the European and North American weedy and invasive hexaploid A. petiolata populations clustered with the diploid P. cakiloidea. Polyphyletic Thlaspi formed two distinct clades easily distinguished morphologically, and two of its six species are segregated into the new genus Mummenhoffia. Elburzia is reduced to synonymy of Didymophysa, and the new combinations D. fenestrata, Lysakia rostrata, Mummenhoffia alliacea, and M. oliveri are proposed and a diagnostic key for determination of Thlaspideae genera is presented. Age estimations based only on calibration by the controversial fossil Thlaspi primeavum resulted in unrealistic old age estimates. Chromosome counts are reported for 16 species.

Foliar and stem epidermal anatomical features of the tribe Cynoglosseae have been studied in detail for the taxonomic identification using light microscopy (LM) and scanning electron microscopic (SEM) techniques. A comparative study was conducted on different plant parts (leaf and stem epidermal anatomy) of 25 species belonging to eight genera of the tribe Cynoglosseae (Boraginaceae) collected from different phytogeographical regions of Iran for the first time. Different qualitative and quantitative characteristics were observed in detail using LM and SEM. Results showed that although generally the stem and leaf anatomical traits were similar, but some diagnostic features were examined for distinguishing the closely related genera in the tribe. The ratio of cortex/diameter of stem and phloem/xylem, the average row number of collenchyma, palisade and spongy cells, structure of trichomes, type of indumentum and palisade arrangement were found taxonomically important. The anatomical characters were statistically analyzed using cluster analysis and principal component analysis. The study found that stem and leaf eccentrics are variable in the genus but constant within species of the same genus. Most species had typical isobilateral leaves, but some showed an incipient dorsoventrally symmetry with a layer of abaxial palisade tissue. Eglandular trichomes were observed found in all the studied species, which were recognized based on structure and function. In present study some novel characters have been observed which are of great interest to the taxonomist for the correct identification some genera delimitations. The characters studied here are of less taxonomic value and delimitating at species level.

No abstract

No abstract

No abstract