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THE ORGANIZATION OF THE VASCULAR SYSTEM IN THE STEMS OF THE NYMPHAEACEAE. II. NYMPHAEA SUBGENERA ANECPHYA, LOTOS, AND BRACHYCERAS
Author(s) -
Weidlich W. H.
Publication year - 1976
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.1537-2197.1976.tb13222.x
Subject(s) - vascular bundle , biology , botany , subgenus , pith , peduncle (anatomy) , vascular tissue , anatomy , xylem , genus
The anatomy and organization of the stem vascular system was analyzed in representative taxa of Nymphaea (subgenera Anecphya, Lotos , and Brachyceras). The stem vascular system consists of a series of concentric axial stem bundles from which traces to lateral organs depart. At the node each leaf is supplied with a median and two lateral leaf traces. At the same level a root trace supplies vascular tissue to adventitious roots borne on the leaf base. Flowers and vegetative buds occupy leaf sites in the genetic spiral and in the parastichies seen on the stem exterior. Certain leaves have flowers related to them spatially and by vascular association. Flowers (and similarly vegetative buds) are vascularized by a peduncle trace that arises from a peduncle fusion bundle located in the pith. The peduncle fusion bundle is formed by the fusion of vascular tissue derived from axial stem bundles that supply traces to certain leaves. The organization of the vascular system in the investigated taxa of Nymphaea is unique to angiosperms but similar to other subgenera of Nymphaea.