SEM studies on vessels in ferns. 17. Psilotaceae

Citation
El. Schneider et S. Carlquist, SEM studies on vessels in ferns. 17. Psilotaceae, AM J BOTANY, 87(2), 2000, pp. 176-181
Citations number
16
Categorie Soggetti
Plant Sciences
Journal title
AMERICAN JOURNAL OF BOTANY
ISSN journal
00029122 → ACNP
Volume
87
Issue
2
Year of publication
2000
Pages
176 - 181
Database
ISI
SICI code
0002-9122(200002)87:2<176:SSOVIF>2.0.ZU;2-W
Abstract
Perforation plates are reported in aerial and subaerial axes of Psilotum nu dum and in aerial axes of Tmesipteris obliqua. In Psilotum, both perforatio ns lacking pit membranes and perforations with pit membrane remnants were o bserved-Perforation plates in Psilotum may consist wholly of one type or th e other. In Tmespteris, perforations have threadlike pit membranes or consi st of porose pit membranes. Wide perforations alternating with narrow pits, a conformation observed in various ferns, were observed in Psilotum (subae rial axes). In Psilotum, perforations are more common in metaxylem than in protoxylem; perforations in protoxylem consist of primary wall areas contai ning small circular porosities ar relatively large circular to oval perfora tions. There are no modifications in the secondary wall framework of protox ylem or metaxylem in Psilotum or Tmesipteris that would permit one to disti nguish presence of perforations or perforation plates with light microscopy , and scanning electron microscopy (SEM) is required for demonstration of p orose walls or perforations. The tracheary elements of the Psilotaceae stud ied have no features nor also observed in other ferns with SEM.