A Taxonomic Revision Of Blechnaceae In China

Based on the field investigation,the reference to a large number of domestic and foreign literatures,this study used morphological,anatomical and palynological methods to evaluate the stability ofthe traits.We explored the variation rules of genera and species in Blechnaceae,then made a new taxonomical revision of Blechnaceae from China.This study could provide some basic data for the classification of Blechnaceae.Results were as follows:1.The valuable classification traits of Blechnaceae were mainly concentrated in rhizomes,leaves and sori.However,the leaf shape varies in different geographical distribution and habitat,so we need to consider the variation of each species.The morphology of rhizome,number of pinna,lobes,petiole and sori are of great value for taxonomy.2.The rhizome scales of Blechnaceae were sword-shaped,lanceolate,ovate-lanceolate,ovate;mainly basifixed,few peltate-based;apex acuminate,few obtuse;margin entire or spiked.The shape,base-fixed pattern,apex and color of scales were played important roles in generic classification,but not in species.3.The leaf epidermal cells of Blechnaceae were irregular;the patterns of anticlinal walls were sinuate;upper and lower epidermises were both hairless.The stomatal apparatus were unevenly distributed in lower epidermises.Nine types of stomatal apparatus were found in Blechnaceae,such as Polocytic-,copolocytic-,aillocytic-,coaxillocytic-,anomocytic-,anomotetracytic-,diacytic-,aisocytic-,aotinocytic-type.Furthermore,there are two or more arrangements existed in one species,but there was always a dominant type of stomata.Leaf epidermal morphological characteristics have a certain systematic significance to the division,but not in species.4.The spores of Blechnaceae were monolte,bilateral symmetric,elliptic,oblong-elliptic or nearly spherical in polar view and reniform or bean-shaped in equatorial view.Spores of this family were mainly lamellate,few were rugale,regulate,lophate and tuberculate.Spores of most species had perine,and ornamentations were always formed form perine,few were formed by exine.The ornamentation of spores had systematic significance in generic and infrageneric classification,and sometimes even had a certain value in discriminating species with similar morphology.5.12 species and 1 variety and 1 form in 7 genera of Blechnaceae were recognized as native to China,detailed descriptions of each taxon and keys to genera and two new combinations were given.