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Variable petal aestivation depicted in floral diagrams, showing the subtending bract in abaxial/lowermost position, two lateral bracteoles, five petals in red and the carpel in blue. Note that the adaxial petal is the innermost in all. (A, B) Ascending petal aestivation with either the abaxial left (A) or the abaxial right (B) petal outermost. (C) The two lateral petals are outermost. (D, E) Either the lateral left (D) or the lateral right (E) petal is in outermost position.
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Background and Aims: The study of floral morphology and ontogeny and the re-investigation of existing data help to uncover potential synapomorphic characters and foster our understanding of phylogenetic relationships that rely primarily on molecular analyses. Goniorrhachis marginata is a monotypic caesalpinioid legume (Leguminosae) that shows some...
Context in source publication
Context 1
... in all studied buds the adaxial median petal is in the innermost position, there are some variations in the strictly cochlear ascending aestivation (Fig. 7). Nonetheless, our results show that certain caesalpinioid characters, such as the position of the innermost adaxial petal, are deeply grounded in the plant genome. Deviations from ascending cochlear aestivation are rare in Caesalpinioideae s.l. In Duparquetia orchidacea petal aestivation is cochlear descending (Prenner and Klitgaard, ...
Citations
... A comparative floral ontogenetic study of Tachigali and related genera would be an interesting topic for future research, perhaps even the key to unveiling the floral homology in the tribe Sclerolobieae, as has previously been shown to be successful in revealing affinities in various other florally disparate legume genera (e.g., Tucker and Kantz 1997;Prenner and Klitgaard 2008;Zimmerman et al. 2013;Bruneau et al. 2014;Prenner et al. 2015;Prenner and Cardoso 2017). For example, in legume subfamily Detarioideae, which houses a large collection of florally diverse genera of predominantly tropical trees, new floral ontogenetic synapomorphies (Prenner and Cardoso 2017), as well as a remarkable evolutionary lability of some floral traits, have been revealed (Bruneau et al. 2014;Ojeda et al. 2019). ...
... A comparative floral ontogenetic study of Tachigali and related genera would be an interesting topic for future research, perhaps even the key to unveiling the floral homology in the tribe Sclerolobieae, as has previously been shown to be successful in revealing affinities in various other florally disparate legume genera (e.g., Tucker and Kantz 1997;Prenner and Klitgaard 2008;Zimmerman et al. 2013;Bruneau et al. 2014;Prenner et al. 2015;Prenner and Cardoso 2017). For example, in legume subfamily Detarioideae, which houses a large collection of florally diverse genera of predominantly tropical trees, new floral ontogenetic synapomorphies (Prenner and Cardoso 2017), as well as a remarkable evolutionary lability of some floral traits, have been revealed (Bruneau et al. 2014;Ojeda et al. 2019). We anticipate that the patterns of flower development recently described for five morphologically distinct species of Tachigali, which have shown how much more ontogenetically similar they are than previously suspected (Casanova et al. 2020), will provide valuable data for phylogenetic comparative analysis of the entire Sclerolobieae. ...
Despite recent advances in revealing the evolutionary history of speciose tropical plant clades, many species radiations are still poorly understood phylogenetically. One of these is the species-rich neotropical genus Tachigali (~ 90 spp.), a caesalpinioid legume lineage of mostly ant-housing canopy trees that has diversified in the tropical rainforest biome across the Andean foothills, Amazon basin, and Atlantic Coastal Forest of Brazil. It is also ecologically dominant across the fire-prone savanna vegetation of the Brazilian Cerrado. The taxonomic history of Tachigali has long been confounded with the genus Sclerolobium, with the two differing in floral symmetry. Here, we reconstruct the phylogeny of Tachigali using densely sampled Bayesian and maximum likelihood analyses of nuclear ribosomal (ITS/5.8S) and plastid (matK and trnL intron) DNA sequences for 67 species. All phylogenetic analyses support Tachigali as monophyletic. We recognize a broad circumscription of Tachigali encompassing species exhibiting both radially and bilaterally symmetrical flowers, and we suggest that the traditional generic concept of Sclerolobium should be abandoned. The poor resolution in the Tachigali phylogeny is suggestive of rapid diversification, which has been observed in other species-rich rainforest-inhabiting plant clades across the Neotropics.
... Besides, the study of reproductive whorls has proved to be of tremendous taxonomic value (Classen-Bockhoff, 2000;Vrijdaghs et al., 2005). A lot of work has been carried out on floral ontogeny in legumes and the data generated has been useful in compiling the legume phylogenetic framework (Tucker, 1984(Tucker, , 1987(Tucker, , 1988a(Tucker, ,b, 1989(Tucker, , 1990(Tucker, , 1991(Tucker, , 1993(Tucker, , 1996(Tucker, , 1998(Tucker, , 2003Ramírez-Domenech and Tucker, 1990;Tucker and Kantz, 2001;Klitgaard, 1999;Prenner, 2004a,b,c,d,e;2011Prenner and Cardoso, 2017;Torke and Mansano, 2009;Wojciechowski et al., 2004;Marazzi and Endress, 2008;Prenner and Klitgaard, 2008;Movafeghi et al., 2010Movafeghi et al., , 2011Naghiloo et al., 2010Naghiloo et al., , 2012Khodaverdi et al., 2014;Prenner et al., 2015;Falcao et al., 2020;Rather et al., 2021). Although the subfamily Papilionoideae has received extensive research on floral development, other sub-families, such as Caesalpinioideae, despite displaying diversity in floral architecture and form, have been understudied in comparison. ...
This study investigates the floral morphology and development of two legume species from the subfamily Caesalpinioideae, Biancaea decapetala (a caesalpinioid), and Albizia julibrissin (a mimosoid), using scanning electron microscopy. The floral organ initiation in A. julibrissin involved the helical orientation of sepals' formation, simultaneous initiation of petals, and formation of the ring meristem in place of stamens. Whereas in B. decapetala, organ whorls grow unidirectionally, from abaxial to adaxial, a characteristic found in the subfamily Papilionoideae. However, the floral development sequence in B. decapetala differs from papilionaceous flowers, as it lacks petal specialization and features a fused staminal tube. While fused sepal tube, free stamens, and short style were observed in flowers of B. decapetala; fused petals, fused staminal tube, and long style occurred in flowers of A. julibrissin. The petal aestivation is valvate in A. julibrissin, compared to ascending cochleate in B. decapetala. The observations during the initiation and developmental stages of floral whorls are essential to unravel the functional specificity of appendages. A. julibrissin belongs to the Mimosoid clade, which was until recently placed outside the Caesalpinioideae subfamily (of which B. decapetala was always been a part of) due to its floral architecture. There has been significant number of discussions and deliberations in the botanical community about the placement of this clade in the subfamily. Understanding of floral development in the subfamily and comparison of caesalpinioids with mimosoids can be crucial in evaluating the phylogenetic placement of the mimosoid clade. While most changes in the developmental sequence may appear subtle and minute, these are imperative for the remarkable disparity in the floral morphology of legumes.
... This family is well known for its floral morphology, in particular its wide variety of shapes, as observed not only in the characteristics papilionaceous flowers, but also in actinomorphic, or asymmetric flowers observed among the group (Tucker, 2003). Studies of floral development have been helping the understanding of such morphological varieties and their homologies among Fabaceae flowers (Bruneau et al., 2014;Leite, Mansano & Teixeira, 2014;Leite et al., 2015;Prenner et al., 2015;Prenner & Cardoso, 2017). However, in Caesalpinioideae, a subfamily with a great variety in terms of floral architecture, many of its groups are poorly documented regarding floral ontogeny and development, mainly after its new circumscription (Tucker, Stein & Derstine, 1985;Tucker, 1988;Tucker, 1991;Tucker, 1992a;Tucker, 1996;Tucker & Kantz, 1997;Prenner, 2004;Marazzi & Endress, 2008), as seen for Tachigali Aubl. ...
... Comparative studies of external morphology and anatomy have helped us to understand the genus circumscription (Casanova et al., 2020); nonetheless, ontogenetic studies can shed new light by the addition of novel characters and, thereby, strengthen knowledge about the flower morphological diversity within Tachigali and among Caesalpinioideae (Tucker, 1992b;Tucker, 2003;Bruneau et al., 2014;Leite, Mansano & Teixeira, 2014;Leite et al., 2015;Prenner et al., 2015;Prenner & Cardoso, 2017). Therefore, the present work aims to perform an ontogenetic study of T. denudata, T. paratyensis and T. spathulipetala, three morphologically representative species from the Tachigali, which includes small and large flowers, variable in morphological terms. ...
... The carpel initiates its development in parallel with the antesepalous stamens, as also reported for Dimorphandra mollis (Caesalpinoideae) (Barros et al., 2017). The premature development of this structure is considered to be widespread among leguminous species (Prenner & Cardoso, 2017). The carpel cleft is positioned adaxially, as well as the carpel extension and the style curvature, an equally frequent characteristic of leguminous species, except for the subfamily Detarioideae, in which the style has an abaxial curvature (Prenner & Cardoso, 2017). ...
Background
The present ontogenetic study reveals variations throughout floral development in three morphologically representative species from the genus Tachigali , allowing a better understanding of floral organs diversity, flower symmetry and their homologies, especially in Fabaceae, a diverse family that exhibits a wide variation in floral architecture. Tachigali (Caesalpinioideae) corresponds to an important Neotropical legumes tree genus with 58 species in Brazil. Species of the genus Sclerolobium Vogel were incorporated in its circumscription, increasing the diversity of its floral morphology.
Methods
This work aims to perform an ontogenetic study of T. denudata , T. paratyensis and T. spathulipetala , morphologically representative species of Tachigali , in order to describe the floral development and to better comprehend the floral morphology varieties among the species, using scanning electron microscopy.
Results
We found the studied species to have floral buds with acropetal and helical development along the inflorescence axis; sepals and petals with helical development, varying the position of the primordia in the bud, according to the different species; stamens with unilateral development and carpel with adaxial curvature. These data correspond to original records of Tachigali ontogeny and contribute to an improved understanding of floral morphology and symmetry with data related to the zygomorphic and early development of the sepals and petals.
... Comparative studies of floral development and morphology have informed taxonomic classifications, and enhanced our understanding of phylogenetic relationships and evolutionary trends across many angiosperm clades, particularly in the early diverging clades of the family Leguminosae, where the constituent genera display an extreme diversity of floral architecture (Tucker 1991(Tucker , 2003Cardoso et al. 2013a, b;Bruneau et al. 2014;Leite et al. 2014Leite et al. , 2015Prenner et al. 2015;Prenner and Cardoso 2017). In the recently recircumscribed subfamily Caesalpinioideae, morphological variation in floral organs can be so high that it is difficult to recognize clear synapomorphies that best characterize the close phylogenetic affinity among florally discrepant genera (LPWG 2013(LPWG , 2017Prenner and Cardoso 2017). ...
... Comparative studies of floral development and morphology have informed taxonomic classifications, and enhanced our understanding of phylogenetic relationships and evolutionary trends across many angiosperm clades, particularly in the early diverging clades of the family Leguminosae, where the constituent genera display an extreme diversity of floral architecture (Tucker 1991(Tucker , 2003Cardoso et al. 2013a, b;Bruneau et al. 2014;Leite et al. 2014Leite et al. , 2015Prenner et al. 2015;Prenner and Cardoso 2017). In the recently recircumscribed subfamily Caesalpinioideae, morphological variation in floral organs can be so high that it is difficult to recognize clear synapomorphies that best characterize the close phylogenetic affinity among florally discrepant genera (LPWG 2013(LPWG , 2017Prenner and Cardoso 2017). ...
... This feature was also observed in the Detarioideae legume Goniorrhachis marginata Taub. (Prenner and Cardoso 2017). Although the connective extensions observed here are not secretory, they can still be taxonomically useful as a possible diagnostic character for the genus. ...
Comparative studies of floral development and morphology have largely contributed to the understanding of taxonomic classification, phylogenetic relationships and evolutionary trends across many angiosperm clades, particularly in the florally diverse family Leguminosae (alternatively Fabaceae). This study aimed to characterize the middle to late stages of floral development and morphological variation of the caesalpinioid genus Tachigali, an evolutionary radiation of predominantly neotropical rainforest trees. Floral buds and flowers of five representative species from Tachigali were analyzed under stereo microscopy, light microscopy and scanning electron microscopy to evaluate informative morphological and developmental characters. Although the genus displays relatively small flowers measuring up to 14 mm long, they are variable in terms of symmetry, structure and size, which have influenced the main taxonomic subdivisions among the species. Here, we show that the floral architecture of Tachigali involves a double whorl of stamens, anthers with dome-shaped connective extension and monosymmetrical hypanthium, owing to the unequal development of its wall at different stages of the floral ontogeny. Such developmental patterns are likely new diagnostic floral characters of Tachigali in the context of the early diverging caesalpinioid clades and reaffirm the circumscription of the genus in order to include the species previously classified within Sclerolobium.
... The plasticity of some of these floral traits has been documented at multiple levels, among major lineages, between closely related genera and within species (Tucker, 2002a(Tucker, , 2002b. However, there is evidence of a highly conserved evolution of gynoecium development in the Detarioideae (Prenner and Cardoso, 2017). ...
Detarioideae is well known for its high diversity of floral traits, including flower symmetry, number of organs, and petal size and morphology. This diversity has been characterized and studied at higher taxonomic levels, but limited analyses have been performed among closely related genera with contrasting floral traits due to the lack of fully resolved phylogenetic relationships. Here, we used four representative transcriptomes to develop an exome capture (target enrichment) bait for the entire subfamily and applied it to the Anthonotha clade using a complete data set (61 specimens) representing all extant floral diversity. Our phylogenetic analyses recovered congruent topologies using ML and Bayesian methods. Anthonotha was recovered as monophyletic contrary to the remaining three genera (Englerodendron, Isomacrolobium and Pseudomacrolobium), which form a monophyletic group sister to Anthonotha. We inferred a total of 35 transitions for the seven floral traits (pertaining to flower symmetry, petals, stamens and staminodes) that we analyzed, suggesting that at least 30% of the species in this group display transitions from the ancestral condition reconstructed for the Anthonotha clade. The main transitions were towards a reduction in the number of organs (petals, stamens and staminodes). Despite the high number of transitions, our analyses indicate that the seven characters are evolving independently in these lineages. Petal morphology is the most labile floral trait with a total of seven independent transitions in number and seven independent transitions to modification in petal types. The diverse petal morphology along the dorsoventral axis of symmetry within the flower is not associated with differences at the micromorphology of petal surface, suggesting that in this group all petals within the flower might possess the same petal identity at the molecular level. Our results provide a solid evolutionary framework for further detailed analyses of the molecular basis of petal identity.
... Floral developmental investigations are known to provide useful characters for phylogenetic studies (e.g. Kirchoff, 1988Kirchoff, , 1998Ronse De Craene & Smets, 1999;Ronse De Craene et al., 1998;Bachelier, Endress & Ronse De Craene, 2011;Prenner & Cardoso, 2017). The primary goal of this study is to document the structure and development of the appendages of Globba, and explore their origins and evolution. ...
Globba is one of the largest genera in the primarily tropical Zingiberaceae. The number of anther appendages is highly diagnostic and has been used along with molecular characters to define subgenera and sections. Four main types of anther morphology are recognized: without appendages and with two, four and six appendages. The six-appendaged anthers are reported here for the first time. Appendages arise from two dorsal ledges that flank the broad connective. Development of two-appendaged and four-appendaged species differs from inception. Previous suggestions that either the proximal or distal appendages of four-appendaged anthers have been lost in two-appendaged species are thus not supported. Early development of six-appendaged anthers is similar to that of four-appendaged species, but two additional, small appendages develop on the ledges between the first-formed appendages. This yields three appendages on each side (six overall). The four appendages of G. geoffrayi differ from all other species in having distal appendages that are much smaller and develop later than the proximal appendages. Development thus suggests that the state in G. geoffrayi evolved from a two-appendaged ancestor. Incorporating this information into a phylogenetic character plot of the number of appendages shows that the possession of two appendages is the most likely plesiomorphic state of the genus, although support for this hypothesis is weak. Our study clarifies the origin and complexity in the development of anther appendages in Globba and highlights their significance in infrageneric relationships in Globba. Two appendages have probably likely arisen at the base of Globba, linked with the presence of a prominent ledge, with variable extensions and reductions of the number of appendages in the various subgenera and sections. ADDITIONAL KEYWORDS: connective-floral development-Globbeae-phylogeny.
... Recent advances have brought an ever-increasing amount of phylogenetic resolution to the papilionoid legumes Torke and Schaal, 2008;Cardoso et al., 2012aCardoso et al., , 2012bCardoso et al., , 2013aCardoso et al., , 2013bQueiroz et al., 2015;Ramos et al., 2016), one of the most diverse and ecologically successful plant radiations with $14,000 species and $484 genera LPWG, 2013a). These phylogenetic advances have given great insights into the floral evolution of papilionoid legumes especially with regard to how plastic it is Prenner and Klitgaard, 2008;Cardoso et al., 2013a;Bruneau et al., 2014;Prenner and Cardoso, 2016) and into the evolutionary persistence and ecological success of legumes throughout global biomes Oliveira-Filho et al., 2013;Pennington and Lavin, 2016). ...
... Prenner, 2004). It remains to be studied whether Haplormosia shows the same pattern of stamen initiation and how this fits into the larger picture of androecial symmetry among Brongniartieae and early-branching papilionoid legumes (Prenner, 2004;Prenner and Cardoso, 2016). ...
The early-branching clades of Fabaceae subfamily Papilionoideae are characterized by their remarkable lability in floral architecture. In contrast, more derived papilionoid lineages are marked by evolutionary conservatism towards strongly bilateral, papilionate flowers. Here, we show an unexpected example of conservatism of a unique floral architecture during the early diversification history of the papilionoids. We built the most comprehensively sampled molecular phylogenetic tree with a focus on the early-diverging papilionoid Dipterygeae clade to evaluate conservatism of the winged papilionate architecture and associated traits related to flower specialization (e.g. zygomorphy, petal differentiation, stable stamen number and stamen sheath). Dipterygeae comprise c. 22 species of mostly giant trees from across tropical forests in Central America and the Amazon, but they are also ecologically dominant in the savannas of the Brazilian Central Plateau. Phylogenetic analyses of nuclear ribosomal ITS/5.8S and plastid matK and trnL intron sequences strongly supported inter-relationships and the monophyly of each genus (Dipteryx, Monopteryx, Pterodon and Taralea). Bayesian relaxed-clock dating and a Bayesian model of ancestral character estimation revealed c. 30 Myr of conservatism of all winged papilionate-related flower traits in a clade comprising the most recent common ancestor of Dipteryx, Pterodon and Taralea, but lability in fruit morphology during the diversification of the entire Dipterygeae clade. Despite Monopteryx and remaining Dipterygeae being florally discrepant, they are collectively defined by a floral synapomorphy that is unique among all papilionoid Fabaceae: the highly differentiated calyx, where the two upper lobes are enlarged and wing-like, whereas the other three lower lobes are reduced. We suggest that the different dispersal strategies and the ancient winged papilionate floral conservatism in Dipterygeae, which has maintained effective ecological interactions with specialized pollinators and ensured the protection of young flower buds and developing fruits, may explain successful evolutionary and ecological persistence of the clade across the main Neotropical biomes.
The early-branching clades of Fabaceae subfamily Papilionoideae are characterized by their remarkable lability in floral architecture. In contrast, more derived papilionoid lineages are marked by evolutionary conservatism towards strongly bilateral, papilionate flowers. Here, we show an unexpected example of conservatism of a unique floral architecture during the early diversification history of the papilionoids. We built the most comprehensively sampled molecular phylogenetic tree with a focus on the early-diverging papilionoid Dipterygeae clade to evaluate conservatism of the winged papilionate architecture and associated traits related to flower specialization (e.g. zygomorphy, petal differentiation, stable stamen number and stamen sheath). Dipterygeae comprise c. 22 species of mostly giant trees from across tropical forests in Central America and the Amazon, but they are also ecologically dominant in the savannas of the Brazilian Central Plateau. Phylogenetic analyses of nuclear ribosomal ITS/5.8S and *Corresponding authors. plastid matK and trnL intron sequences strongly supported interrelationships and the monophyly of each genus (Dipteryx, Monopteryx, Pterodon and Taralea). Bayesian relaxed-clock dating and a Bayesian model of ancestral character estimation revealed c. 30 Myr of conservatism of all winged papilionate-related flower traits in a clade comprising the most recent common ancestor of Dipteryx, Pterodon and Taralea, but lability in fruit morphology during the diversification of the entire Dipterygeae clade. Despite Monopteryx and remaining Dipterygeae being florally discrepant, they are collectively defined by a floral synapomorphy that is unique among all papilionoid Fabaceae: the highly differentiated calyx, where the two upper lobes are enlarged and wing-like, whereas the other three lower lobes are reduced. We suggest that the different dispersal strategies and the ancient winged papilionate floral conservatism in Dipterygeae, which has maintained effective ecological interactions with specialized pollinators and ensured the protection of young flower buds and developing fruits, may explain successful evolutionary and ecological persistence of the clade across the main Neotropical biomes.
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