Accession Number : AD0618839

Title :   STUDIES IN THE FERN GENUS CHEILANTHES SWARTZ. I. THE LEAF BLADE ANATOMY OF SOME SPECIES OF THE GENUS,

Corporate Author : MICHIGAN STATE UNIV EAST LANSING

Personal Author(s) : Knobloch,I. W. ; Volz,P. A.

Report Date : 1963

Pagination or Media Count : 26

Abstract : The anatomy of the ultimate segments of 35 species of the genus Cheilanthes is covered in this paper. All of these have been termed xerophytes or near xerophytes by various authorities. All of the species examined had large bulliform cells in the upper epidermis except C. meifolia, C. siliquosa and C. california. The lower epidermal cells are usually smaller than those of the upper layer but stomates are present in the former and not in the latter. Chloroplasts are a regular feature of the epidermis in many species. The palisade parenchyma varies considerably from species to species. Some have typical, rectangular cells; in others the cells are scarcely longer than broad and in some the entire mesophyll is quite uniform. The generalizations of Marsh on American species and of Nayar on Indian species do not hold throughout the study. One of the striking features of many of the species, if not all, is the presence of H- or Y-shaped cells in the palisade region. The spongy mesophyll is usually loosely organized and the cells are armed. The bundles are concentric, endodermal sheath and pericycle are present and the xylem tracheids are always more numerous than the phloem sieve tubes. The false indusium is formed by the reflexed margins of the segments. The epidermises may merge or remain separated by mesophyll in the indusium. The reflexed edges may terminate in a flap of linearly-spaced cells or the flap may be absent. Anatomical study does not by itself seem to clarify any of the problems of relationship and speciation known to exist within this group. (Author)

Descriptors :   (*PLANTS(BOTANY), MORPHOLOGY(BIOLOGY)), CELLS(BIOLOGY), CELL STRUCTURE, BIOLOGY

Distribution Statement : APPROVED FOR PUBLIC RELEASE