A Systematic Study On The Genus Coniogramme

Coniogramme Fee,which belongs to the Cryptogrammoideae of Pteridaceae,is mainly distributed in tropical and subtropical areas of Asia,and China is the geographical distribution center.Coniogramme has long been regarded as one of the most contentious groups of ferns with respect to its classification.The author has carried out detailed specimen inspection and field observation for this genus,and used six chloroplast gene fragments(trnH-psbA,trnL-F,rps4,rps4-trnS,matK and rbcL)to construct phylogenetic trees.Samples were taken from China,India and Africa.The major results are as follows:1.Coniogramme constitutes as a monophyletic clade,and its internal systematic relationship contradicts Shing's classification based on the teeth and hydathodes.2.C.merrillii is the basal taxa of Coniogramme and forms sister to the rest of the genus.3.Systematic studies show that the genus is divided into five groups(C.merrillii group,C.japonica&C.robusta group,C.rosthornii group,C.fraxinea group and C.intermedia group).Sole species C.merrillii constitutes C.merrillii group;C.japonica&C.robusta group includes C.japonica,C.robusta,etc.The main characteristics of the group are sparse and shallow teeth on the margins of the pinnules and hydathodes not extending to teeth base;C.rosthornii group includes C.rubescens,C.rosthornii,C.taipaishanensis,etc.Most members of the C.rosthornii group have densely papillae with short and stiff hair on the back of the lamina;The members of C.fraxinea group are distributed in tropical or subtropical regions,and most of them have pinnules with entire margin;The main characteristics of C.intermedia group are fine and ascending teeth.4.C.procera is closely related to the ser.Fraxineae,and they are sister groups with C.petelotii.5.The description of C.wilsonii in Chinese literature is consistent with the morphological characteristics of C.fauriei.The specimens currently misidentified as C.wilsonii in China should be corrected to C.fauriei.In addition,after detailed study of the types and the original description of C.wilsonii,we think C.sinensis should be considered as a synonym of C.wilsonii.