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COMPARATIVE ANATOMY OF THE ASPIDIACEAE. I. STELAR PATTERN DEVELOPMENT IN YOUNG SPOROPHYTES OF TECTARIA
Author(s) -
White Richard A.
Publication year - 1970
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1970.tb09837.x
Subject(s) - biology , sporophyte , nodal , trace (psycholinguistics) , botany , anatomy , linguistics , philosophy
Vascular tissue development in young sporophytes of seven species of Tectaria is described. Special emphasis is placed on stelar‐pattern ontogeny, the transition region between the primary root and the shoot, and changes in the nodal pattern associated with the sequential production of leaves. The changes in stelar pattern which occur prior to the production of the 8th leaf can be placed in three general categories. In the simplest category, development progresses from a protostele to a siphonostele with a unilacunar one‐trace nodal pattern. Species in a second category pass through the one trace per gap pattern to a siphonostele with a unilacunar two‐trace nodal pattern. The most complex category includes two species in which by the 3rd or 4th leaf a dictyostele with a unilacunar two‐trace nodal pattern is established. The significance of this pattern variation in young Tectaria sporophytes of equivalent stages in relation to taxonomic problems in the Aspidiaceae is discussed. In addition, the occurrence of a unilacunar one‐trace nodal pattern in these and other species of leptosporangiate ferns is related to the standard concept that a unilacunar two‐trace nodal pattern is basic in the ferns.