Calla palustris (Araceae): New palynological insights with special regard to its controversial systematic position and to closely related genera

Autor(en)

Silvia Ulrich, Michael Hesse, David Bröderbauer, Josef Bogner, Martina Weber, Heidemarie Halbritter

Abstrakt

Almost all systematic treatments agree that Calla is a puzzling case, being a highly autapomorphic taxon with obscure relationships. In molecular-based classifications the variable placements of Calla within Aroideae conflict strongly with those in morphologically and anatomically based systematic classifications, which treat the genus as a subfamily (Calloideae) of its own. We studied the pollen morphology and ultrastructure of Calla by light and electron microscopy, and mapped the relevant pollen characters as well as some flower characters to the proposed placements of Calla within the Araceae as indicated in the various molecular phylogenies. Calla pollen is extraordinary within the entire Araceae. Pollen grains are small, and basically disulcate or with a ring-like aperture. The ornamentation is psilate to perforate, and the pollen wall consists of a sporopolleninous tectate-columellate exine. These pollen characters are shared with those of several earlier-diverging aroid taxa, especially with those of subfamily Zamioculcadoideae, whereas pollen characters in members of subfamily Aroideae deviate significantly. These findings are in accordance with other floral characters. Therefore, we propose that Calla is best placed in a transition zone between either subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Aroideae (Aroideae clade) or between subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Lasioideae.

Organisation(en)

Externe Organisation(en)

Botanischer Garten München-Nymphenburg

Journal

Taxon: international journal of plant taxonomy, phylogeny and evolution

Band

62

Seiten

701-712

ISSN

0040-0262

DOI

https://doi.org/10.12705/624.34

Publikationsdatum

2013

Peer-reviewed

Ja

ÖFOS 2012

106008 Botanik, 106049 Ultrastrukturforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c7c446b2-e1c2-4c9d-8227-cfc69948f7a7