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Medientyp:
E-Artikel
Titel:
Studies on Morphology and Affinity of the Parkeriaceae I. Morphological Observations of Ceratopteris thalictroides
Beteiligte:
Pal, Niranjan;
Pal, Sunanda
Erschienen:
The University of Chicago Press, 1962
Erschienen in:
Botanical Gazette, 124 (1962) 2, Seite 132-143
Sprache:
Englisch
ISSN:
0006-8071
Entstehung:
Anmerkungen:
Beschreibung:
1. The present paper deals with morphological observations of Ceratopteris thalictroides (L.) Ad. Brongn. growing near Calcutta. The plants are annual, semiaquatic or aquatic, and rooted or free-floating. The habit is considerably influenced by the conditions of growth. The size and form of the successive sterile leaves are regularly graded, leading to a uniform type of highly pinnatisect fertile leaves. Scales occur on the rhizome, and the young leaf possesses both scales and hairs. 2. The anatomy of the root, rhizome, and leaf gives indications of the aquatic habitat. The rhizome in juvenile plants is protostelic. This gradually is transformed into a highly dissected dictyostele with medullary strands in the later-formed regions. The number of vascular strands and their organization in the leaf trace is accordingly variable. The larger peripheral meristeles of the rhizome are arranged in an irregular ring and are intimately related to the irregularly distributed smaller medullary strands. The medullary meristeles of rhizome and leaf, on the other hand, have a little correlation. The meristeles are basically hadrocentric, but size, shape, and construction are greatly variable as a result of high degree of anastomosis. 3. Endodermis and pericycle in the rhizome and leaf develop from a common mother-cell layer, cortical in origin. The endodermis is of the primary type. A feeble cortical mechanical tissue develops around each meristele. 4. The leaf epidermis shows some characteristic features. The mesophyll tissue remains undifferentiated. 5. The adventitious root originates in the hypodermis of the leaf base and the lateral root in the endodermis of the parent root. The histogenesis of the root and its mature structure have been described in detail and discussed. The endodermis and pericycle have a separate origin in roots.