Morphological And Anatomical Studies On 31 Species Of Pteridophytes From Heilongjiang

The epidermal structures, scales and cross section of 31 species from different families in Heilongjiang Province were investigated under light microscopes.The results indicated that:1.The two subgenus of Equisetum shows apparent differences in the morphology of epidermis and stomatal position. Stomatas are both paracytic type and composed of two guard cells and two subsidiary cells,subsidiary cells located above the guard cells.Radial pattern of the stomatas derived from the apophysis on the ventral wall of the guard cells.The stem structure of five plants are similar,there are metaxylems in the vascular bundle.There are one or two layers of endodermis among the five species.2.The leaf epidermal cells of 26 species of ferns in Heilongjiang are mostly irregular, the anticlinal walls of the upper and lower epidermal cells are wavy;There are six types of stomatal apparatus:Polocytic type,Axillocytic type,Aisocytic type,Anomotetracytic type,Anomocytic type and Pericytic type,each plant with one to four different types of stomatal apparatus;all the stomatal apparatuses only occur in the lower epidermis and distribution along the long axis of the leaves.3.The shape, mesh and edge features of the ferns can be used as to classification.4.The cross sections of the petioles show that the vascular bundle of the ferns investigated are all amphicribral,can be divided into three types:(1)There is only one vascular bundle in the petiole,such as Sceptridium robustum (Rupr.) Lyon,Osmunda cinnamomea L.var.asiatica Fernald,Aleuritopteris argentea (Gmel.) Fee,Adiantum pedatum L.,Camptosorus sibiricus Rupr.and Woodsia polystichoides Eaton;(2)The vascular patterns of the basal part of stipe are two meristeles distributing in the shape of "å…«",the xylems in the two meristeles are typical hippocampus type and gradually combine into amphicribral vascular bundles upwards, such as all the ferns of Athyriaceae observed,Phegopteris connectilis (Michx.) Watt,Matteuccia struthiopteris (L.) Todaro,Onoclea sensibilis L.var.interrupta Maxim.and Lepisorus ussuriensis (Regel et Maack) Ching;(3)Several vascular patterns regularly arrange in the ground tissue,such as Pteridium aquilinum (L.) Kuhn var.latiusculum (Desv.) Underw.ex Heller,all the ferns of Dryopteridaceae observed and Pyrrosia davidii (Baker) Ching.5.The stomatas of the ferns observed are in the same plane with the epidermal cells with two guard cells;The mesophyll do not differentiate into palisade and spongy tissue except Sceptridium robustum (Rupr.) Lyon, Osmunda cinnamomea L.var.asiatica Fernald, Aleuritopteris argentea (Gmel.) Fee,Lepisorus ussuriensis (Regel et Maack) Ching and Pyrrosia davidii (Baker) Ching.6.Compared with the ferns of Leptosporangiopsida,the plants of Equisetaceae,Sceptridium robustum (Rupr.) Lyon and Osmunda cinnamomea L.var.asiatica Fernald are more primitive on the morphological and anatomical characteristics.