BACKGROUND AND AIMS The taxonomic complexity of Crataegus (hawthorn; Rosaceae, Maleae), especially in North America, has been attributed by some to hybridization in combination with gametophytic apomixis and polyploidization, whereas others have considered the roles of hybridization and apomixis to be minimal. Study of the chemical composition and therapeutic value of hawthorn extracts requires...

DNA barcodes can facilitate identification of organisms especially when morphological characters are limited or unobservable. To what extent this potential is realized in specific groups of plants remains to be determined. Libraries of barcode sequences from well-studied authoritatively identified plants represented by herbarium voucher specimens are needed in order for DNA barcodes to serve th...

With the determination of biological activity different components in chemistry propolis, its importance has increased day by and use field integrative medicine become widespread. Propolis is not used crude form due to physical properties, it have be extracted. The type solvent extraction process very important for efficiency propolis. Solvents commonly propolis extraction; are water, ethanol m...

M.M. DAvaS,*t L.J. BERG,t..A.Y. Ln~,*t B. FAZEKAS DE ST. GROTH,t B. DEVAUX,*t C.G. SAGERSTROM,t P.J. BJORKMAN,r AND J .F . ELLIOTTtw *Howard Hughes Medical Institute and tThe Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305-5428; J~Biology Division, The California Institute of Technology, Pasadena, California 95205; w DNAX Research In...