Comparative floral anatomy and evolutionary interpretations of cryptic dioecy in <i>Ocotea velloziana</i> (Lauraceae)

Autor(en)
Sarah Juventina Barbosa da Silva, Flávia Maria Leme, Ana Paula Sales de Araujo Franco, Rosani do Carmo de Oliveira Arruda, Jürg Schönenberger, Flávio Macedo Alves
Abstrakt

Ocotea velloziana (Lauraceae) is a species with cryptic dioecy. The staminate flowers of this species have a pistillode and pistillate flowers have staminodes, which often makes it difficult to describe circumscribe the reproductive system correctly. Therefore, to understand the evolution of dioecy in this species, the morphology of both floral morphotypes needs to be described. We apply traditional and modern approaches to describe the comparative floral anatomy of the two floral morphotypes in O. velloziana. We found that the pistillate flowers have fewer (three) vascular traces in the tepals (compared to five traces in the tepals of the staminate flowers). The pistillode and the staminodes in the flowers of O. velloziana are smaller and less vascularized than their homologous, fertile counterparts, the pistils and stamens. In addition, even though the nectaries are smaller in pistillate flowers, their basic morphology and vascularization are similar in the two floral morphotypes. Our results suggest androtepaly in O. velloziana, however future ontogenetic studies and investigation of the vascularization are necessary in other Lauraceae species to clarify this issue. The nectaries have originated from the hypanthium and may be characterized as nectar-secreting emergencies not homologous to the stamens.

Organisation(en)
Department für Botanik und Biodiversitätsforschung
Externe Organisation(en)
Universidade Federal de Mato Grosso do Sul
Journal
Rodriguésia
Band
75
Anzahl der Seiten
17
ISSN
2175-7860
Publikationsdatum
2024
Peer-reviewed
Ja
ÖFOS 2012
106008 Botanik, 106042 Systematische Botanik, 106012 Evolutionsforschung
Schlagwörter
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/ec812c8e-a906-4cd9-9f1c-bdbf47893664