Authors:	Claßen-Bockhoff, Regine Frankenhäuser, Hebert
Title:	The ‘male flower’ of Ricinus communis (Euphorbiaceae) interpreted as a multi-flowered unit
Online publication date:	21-Oct-2020
Year of first publication:	2020
Language:	english
Abstract:	One of the most exciting questions in botany refers to the nature of the angiosperm flower. While most flowering structures are easily identified as flowers, there are few examples lying in-between flowers and inflorescences. Such an example is the staminate unit (‘male flower’) in Ricinus communis (Euphorbiaceae) famous for its branched ‘staminal trees.’ The units were controversially interpreted in the past. Today, they are seen as flowers with multiple branched stamen-fascicles. In the present paper, the recently described floral unit meristem is used to reinterpret the staminate units in Ricinus. This meristem shares almost all characteristics with a flower meristem, but differs from it in the number of fractionation steps resulting in multi-flowered units. Reinvestigation of the development confirms previous studies illustrating up to six fractionation steps before the meristem merges into anther-formation. Fractionation starts early at a naked meristem, covers simultaneously its whole surface, shows an all-side instead of unidirectional splitting pattern and continues repeatedly. Based on the present knowledge, it is plausible to interpret the ‘male flower’ as a floral unit with multiple staminate flowers each reduced to a single anther. This interpretation is in accordance with the many examples of reduced flowers in the Euphorbiaceae.
DDC:	570 Biowissenschaften 570 Life sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 10 Biologie
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-5240
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	Frontiers in cell and developmental biology 8
Pages or article number:	Art. 313
Publisher:	Frontiers Media
Publisher place:	Lausanne
Issue date:	2020
ISSN:	2296-634X
Publisher URL:	https://doi.org/10.3389/fcell.2020.00313
Publisher DOI:	10.3389/fcell.2020.00313
Appears in collections:	JGU-Publikationen