ISSN:
1615-6110
Keywords:
Monocotyledons
;
Zingiberaceae
;
Nicolaia elatior
;
Morphological interpretation of the tepals
;
comparison withLiliaceae
;
phylogenetic implications
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Nicolaia elatior is used as an example to demonstrate that the “mucronate” tepals ofZingiberaceae correspond to hypsophylls (bracts) consisting of a leaf sheath and a rudimentary “Oberblatt” (= leaf petiole + lamina) represented by the “mucro”. Evidence for this interpretation is furnished by all available criteria: leaf sequence (exhibiting a complete continuum of forms from foliage leaves over cata- and hypsophylls to the tepals), nervature, and ontogeny. The present conception is compared with the well-founded thesis ofLeinfellner that the perigone ofLiliaceae is derived from the androecium. The different morphological status of the perigone in both families is not regarded as the result of different phylogenetic origin, but as a manifestation of “morphogenetic transgressions” from one phyllome category to an adjacent one: In theLiliaceae the perigone is under a strong morphogenetic influence of the androecium, and therefore displays staminal characters, in theZingiberaceae it is under the dominating influence of the extrafloral region, and thus appears as a hypsophyllous structure. If this assumption of a morphologically “oscillating” perigone is correct, it will be fundamentally impossible to demonstrate unequivocally the phylogenetic origin of the monocotyledonous perigone.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00984378
