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SOME ASPECTS OF VASCULAR DIFFERENTIATION IN ROOTS OF CASSIA
Author(s) -
Hayat Mohammed Arif,
Heimsch Charles
Publication year - 1963
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.1537-2197.1963.tb06577.x
Subject(s) - biology , botany , cassia , xylem , phloem , herbaceous plant , apex (geometry) , sieve tube element , vascular bundle , vascular tissue , stele , secondary growth , medicine , alternative medicine , pathology , traditional chinese medicine
Hayat, Mohammed Arif (North Dakota State U., Fargo), and Charles Heimsch. Some aspects of vascular differentiation in roots of Cassia. Amer. Jour. Bot. 50(10): 965–971. Illus. 1963.—Vascular development, with emphasis on the differentiation of the protophloem, was studied in tips of primary roots of 18 species of Cassia. Variations in levels of protophloem sieve tube maturation were observed among roots of different species as well as among those of different length in the same species. In general, protophloem matured at greater distances from the apex in roots with the larger diameters. Compared with woody species, herbaceous species exhibited greater uniformity in levels of protophloem maturation, and this was correlated with greater uniformity in root diameter. Roots were either triarch or tetrarch. In some species with tetrarch roots, a change to a triarch pattern occurred during early growth. Structural changes in the differentiating root tip which involve the loss of a xylem arm and subsequent fusion of phloem strands are described.