Abstract
Fleshy fruits occur in several monocot orders and families, and it is generally assumed that they have been derived from capsular fruits many times during the of monocot lineages. Huber hypothesized in 1969 that most capsules in Asparagales are derived secondarily from berries and that this transformation was correlated with the of phytomelan-coated seeds, a pivotal character in his circumscription of Asparagales as part of reclassifying Liliaceae s.l. Dahlgren and co-workers suggested several parallel derivations and reversals in this character, e.g., the transformation sequence trifollicular fruits → capsules → berries → capsules → berries. Mapping of fleshy fruits on a phylogeny based on molecular characters indicates that Asparagales do not have fleshy fruits as a basal character. Dahlgren's cyclic character evolution hypothesis is not supported by the distribution of dry and fleshy fruits, and there is no obvious correlation between baccate fruits and phytomelaniferous seeds in Asparagales. Phytomelaniferous seeds are not an evident synapomorphy of Asparagales as presently circumscribed. The anatomy and development of different capsular and baccate fruits in selected genera are studied in an ongoing project to reveal homologies and establish an adequate fruit typology. Some observations of texture and dehiscence structures in dry and fleshy capsules and in typical berries from hypogynous and epigynous flowers are reported in this paper.
Highlights
Fruit characters have been given considerable attention in both classic and modern monocot taxonomy
In the liliiflorous monocots the "typical" gynoecium is a three-carpellate superior ovary with axile placentation, a single style and several ovules, but degree of fusion and occurrence of nectaries varies, and epigyny occurs in several clades (Rudall 2002)
"A postulated evolutionary sequence of fruit types in the ancestors of Asparagales, in the Liliiflorae, represents an interesting cyclic process. [...] The capsules of many Asparagales might be secondary to berries, which are probably, in their turn, derived from capsules with phytomelan-coated seeds
Summary
Fruit characters have been given considerable attention in both classic and modern monocot taxonomy. In the liliiflorous monocots (the families that in APG II [Angiosperm Phylogeny Group 2003] constitute Asparagales, Liliales, Dioscoreales, and Pandanales) the "typical" gynoecium is a three-carpellate superior ovary with axile placentation, a single style and several ovules, but degree of fusion and occurrence of nectaries varies, and epigyny occurs in several clades (Rudall 2002). Presence of fleshy fruits has been an important distinguishing character for some traditional groupings at family rank (e.g., Smilacaceae, Convallariaceae, Luzuriagaceae, Philesiaceae), and several genera have occasionally been raised to family level with special reference to this trait (e.g., Dianella, Behnia, ·Petermannia). The occurrence and evolution of berries in Asparagales was given special attention by Huber and Dahlgren, who pioneered the modern research in monocot phylogeny (see below)
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