ISSN:
1615-6110
Keywords:
Angiosperms
;
Asteraceae
;
Heliantheae
;
Ambrosia
;
Anther
;
crystals
;
pollen
;
sperm cells
;
tapetum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Staminate flowers of giant ragweed,Ambrosia trifida L. (Asteraceae, tribeHeliantheae, subtribeAmbrosiinae) were processed into resin and sectioned 1–2 µm thick. The invasive (amoeboid) anther tapetum remains parietal until microspores are released from tetrads, then it swells and invades the locule, merging gradually into a single protoplast that flows among the microspores. After the tapetal membrane ruptures at late microspore stage, tapetal debris fills the locule, then disappears as pollen matures. Pollen becomes tricelled before anthesis. The two sperm cell nuclei are slender and wormlike. The present report supports the two generalizations that invasive tapetum and tricelled pollen are attributes of theAsteraceae.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00937677
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