Morphology of the bracts of Elatostema(Urticaceae)and the evolutionary trends in them Chemical constituents from inflorescence bracts of Arctii Fructus Phylogeny and Evolution of Bracts and Bracteoles in Tacca (Dioscoreaceae) Seed germination characteristics of the desert subshrub Atriplex cana and its ecological significance Bracts and bracteoles Morphology of Pleurospermum Hoffm. in Kun-Lun Mountains and Its Taxonomic Significance Morphology of the bracts of Elatostema(Urticaceae)and the evolutionary trends in them Morphogenesis of Female Reproductive Organs in Carpinus turczaninowii and Ostryopsis davidiana (Betulaceae)