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Transverse section series of floral bud including calyptra (C) and three preceding leaves (L1-L3) with vascular bundles outlined of Eupomatia bennettii. A, Upper level of calyptra closed by irregular lobes (asterisks). B, Slightly lower level. C, Upper level of androecium; in the center, the last remnants of irregular lobes (asterisks). D, Lower level of androecium. E, Lowermost level in which concavity of floral apex can be recognized by the hole in the center; attachment level of calyptra on lower side and vascular traces of calyptra joining the floral vasculature. F, Floral base below calyptra attachment. G, Attachment level of preceding leaf. H, Attachment level of second preceding leaf. Magnification mm. bar p 0.5
Source publication
Early floral development in Eupomatia bennettii and Eupomatia laurina was studied with scanning electron microscopy and serial microtomy to focus on initiation and development of the calyptra and initiation and phyllotaxis of the floral organs. Phyllomes preceding the calyptra are distichous or spirodistichous in arrangement. In both species, the c...
Context in source publication
Context 1
... of the calyptra at its tip. The calyptra contains a large number of vascular bundles. However, as can be expected from its circular growth, there is no main vascular bundle, and the bundles do not form an obvious pattern, in contrast to the preceding leaves, which have a distinct apex and therefore a conspicuous median vas- cular complex ( fig. ...
Citations
... Calyptrate flowers are observed in many lineages of angiosperms, including Vitaceae (Soejima & Wen, 2006), Eupomatiaceae (Endress, 2003) and Myrtales (e.g. Goldenberg & Meirelles, 2011;Kriebel et al., 2015). ...
... Their anthetic condition, in which imbricate petals fall as a unit can still be used as a trait of taxonomic value if treated as a 'pseudocalyptra', but should not be treated as homologous to 'true' calyptras. This proposed terminology may or may not be valid for calyptrate species outside Myrtaceae, such as those found in Eupomatiaceae (Endress, 2003) or Melastomataceae (Goldenberg & Meirelles, 2011). In these groups, other organs can be involved (e.g. ...
... In these groups, other organs can be involved (e.g. bracts in Eupomotiaceae, Endress, 2003), so further comparative studies will need to be performed before a stable terminology that encompasses all the diversity of calyptras in angiosperms can be established. ...
Shedding a fused perianth as a calyptra at anthesis is a trait that has evolved independently multiple times in angiosperm evolutionary history. However, calyptras do not correspond to homologous structures in all cases. Here, we describe calyptra development in the evolutionary context of Myrtaceae tribe Syzygieae. We use scanning electron and light microscopy to contrast calyptra development in calyptrate and non-calyptrate species in the group. Results show that calyptras in Syzygieae are not all homologous, but correspond to two ontogenetically distinct structures involving different perianth whorls that resemble each other by convergence: a calycine structure, in which the sepals are fused; and a pseudocalyptra, in which petals fall as a single unit but are not fused. Presence of non-calyptrate flowers is the ancestral state in the tribe, and both calyptra types appeared multiple times in the evolution of the group, with infrequent reversals from the calyptrate to the non-calyptrate state. Results highlight the fact that similar terminology in non-homologous structures can affect even relatively restricted lineages. The recurrent evolution of the calyptra in Syzygieae, with little evidence for reversal, shows that these structures may be advantageous in certain conditions but also correspond to an evolutionary dead-end in the group. ADDITIONAL KEYWORDS: calyx-convergence-corolla-ontogeny-perianth-underlying homology.
... calyptrae). In flowering plants, fused sepals, petals, and/or bracts can form the calyptra, which cover and protect interior parts of immature flowers ( Fig. 1A from Endress 2003). Calyptra is also the term used for the exterior most cell layers of the root cap of monilophytes and lycophytes ( Fig. 1B from Imaichi & Kato 1991;Bierhorst 1985). ...
... The moss calyptra is established as an independent organ upon detachment of the upper portion figure 1C reprinted with permission from Endress (2003). B. Longitudinal section through the apex of a Selaginella delicatula (Desv. ...
The calyptra is a small, maternal gametophyte structure that covers the apex of the offspring sporophyte and is critical for the transition from seta formation to capsule differentiation in many moss taxa. It has been hypothesized to function by (1) providing a mechanical constraint that coordinates the development of the presumptive capsule, (2) secreting hormones that influence sporangium differentiation, (3) physically protecting the undifferentiated capsule region, (4) preventing water loss from the sporophyte apex, and/or (5) lowering the rate of sporophyte transpiration. This review explores the experiments that have tested these hypotheses and the evidence that has been found to support or refute them from scientific literature dating back to the late 1700's. Across mosses, calyptrae come in a wide array of shapes and sizes, which may correlate with aspects of morphology, habitat, and function. The overarching objective of this paper is to renew discussion about and research into this small, but important moss organ. ©2019 by The American Bryological and Lichenological Society, Inc.
... Для клады Eupomatiaceae/Annonaceae характерны такие синапоморфии как: двурядные листья, медианный профил (Endress 1993), пыльцевые зерна с кольцевой апертрой (Le Thomas, 1980Thomas, , 1981Woodland & Garlick, 1982), руминированными семенами (Corner, 1976;Меликян, Плиско, 1988;Woodland 1982), и некоторые другие. В тоже время Eupomatiaceae имеют синапоморфные признаки и с Himantandraceae: сходное строение беспокровного цветка, окруженного брактеей, опадающей в виде калиптры, развитие внутренних стаминодиев с разнообразными секреторными структурами (Armstrong & Irvine, 1990;Endress, 1977Endress, , 1984aEndress, , b, 1993Endress, , 2003, беспокровная, гладкая экзина (Woodland & Garlick, 1982). ...
... For this reason, studies on large, tropical and/or taxonomically complicated taxa are rare in comparison with relatively species-poor (e.g. Endress, 2003) and/or temperate plant groups (e.g. Webster and Gilmartin, 2003). ...
Background and aims:
Comparative floral ontogeny represents a valuable tool to understand angiosperm evolution. Such an approach may elucidate subtle changes in development that discretely modify floral architecture and underlie reproductive lability in groups with superficial homogeneous morphology. This study presents a comparative survey of floral development in Eugenia (Myrtaceae), one of the largest genera of angiosperms, and shows how previously undocumented ontogenetic trends help to explain the evolution of its megadiversity in contrast to its apparent flower uniformity.
Methods:
Using scanning electron microscopy, selected steps of the floral ontogeny of a model species (Eugenia punicifolia) are described and compared with 20 further species representing all ten major clades in the Eugenia phylogenetic tree. Additional floral trait data are contrasted for correlation analysis and character reconstructions performed against the Myrtaceae phylogenetic tree.
Key results:
Eugenia flowers show similar organ arrangement patterns: radially symmetrical, (most commonly) tetramerous flowers with variable numbers of stamens and ovules. Despite a similar general organization, heterochrony is evident from size differences between tissues and structures at similar developmental stages. These differences underlie variable levels of investment in protection, subtle modifications to symmetry, herkogamic effects and independent androecium and gynoecium variation, producing a wide spectrum of floral display and contributing to fluctuations in fitness. During Eugenia's bud development, the hypanthium (as defined here) is completely covered by stamen primordia, unusual in other Myrtaceae. This is the likely plesiomorphic state for Myrteae and may have represented a key evolutionary novelty in the tribe.
Conclusions:
Floral evolution in Eugenia depends on heterochronic patterns rather than changes in complexity to promote flexibility in floral strategies. The successful early establishment of Myrteae, previously mainly linked to the key innovation of fleshy fruit, may also have benefitted from changes in flower structure.
... Calyptrate flowers are observed in many lineages across angiosperms, such as Vitaceae ( Soejima and Wen, 2006), Eupomatiaceae (Endress, 2003), and in the order Myrtales (e.g. Goldenberg and Meirelles, 2011;Kriebel et al., 2015). ...
Myrteae is the most diverse tribe in the species-rich angiosperm family Myrtaceae. Myrteae species play a critical ecological role in tropical forests and savannas, biomes with some of the highest biodiversity on earth. Hence there is a growing interest in its use as a model for evolutionary, ecological and conservation studies. However, morphologically homogeneous reproductive structures cause taxonomic instability and jeopardize modelling and conservation initiatives. This study demonstrates how evolutionary patterns are underpinned by floral traits in Myrteae. Aims are approached using combined phylogenetic and morphological analyses in two work packages (WP): WP1 increases understanding of systematics and floral evolution in Myrteae based on multiloci molecular matrices for a near complete generic sample. The framework is used to interpret biogeography, diversification and over-arching patterns of floral morphology and development; data are reciprocally combined to illuminate those processes. WP2 presents four case studies using floral development and multidimensional trait analysis to address questions related to systematic complexity, phylogenetic heterogeneity and theoretical cladistics concepts, such as evolution of homoplastic traits. Results harness Myrteae as a model group to address relevant questions in plant evolution and systematics; the applicability of this approach to similar questions in other diverse tropical angiosperm groups is discussed.
... The monogeneric family Eupomatiaceae with three species distributed in eastern Australia and New Guinea (Endress, 2003;Jessup, 2002) are nested in Magnoliales sensu APG IV (2016) and are strongly supported as sister to Annonaceae (Doyle & Endress, 2000;D. Soltis et al., 2000D. ...
... In the pre-molecular era, based on comparative morphological data Eupomatiaceae were linked with Annonaceae, primarily due to similarities in vegetative morphology and palynology (Uphof, 1959;Woodland & Garlick, 1982;Takhtajan, 2009) or Himantandraceae, primarily based on comparative studies of floral structure (Endress 1977(Endress , 1984a and seed structure (Melikian & Plisko, 1988a), or with both Annonaceae and Himantandraceae (Morawetz, 1988;Endress, 2003). ...
Based on morphological characters the monogeneric family Eupomatiaceae has been traditionally included in Magnoliales, closely related to Magnoliaceae, Himantandraceae or Annonaceae. This is well supported by molecular phylogenetic studies, and Eupomatiaceae appear strongly supported as sister to Annonaceae. Some specific characters of reproductive organs of Eupomatia have been regarded as autapomorphies of Eupomatiaceae. In earlier studies of Eupomatia fruits, the endocarp has been described as undifferentiated. Current research revealed the following notable characters of Eupomatiaceae: a difference in fruit wall structure of peripheral and inner fruiting carpels by congenital fusion of the peripheral carpels with the receptacle (epicarp) from early differentiation of mesocarp, and late growth of endocarp cells in a radial direction resulting in a parenchymatous palisade endocarp shortly before fruit maturation. This study also demonstrates that pericarp development and structure in mature fruits of Eupomatia differ conspicuously from other families of Magnoliales and are more similar to those of some Laurales. This is in addition to the cup-shaped receptacle and inferior ovary (fruit) found in several Laurales, but not other Magnoliales, which could be the result of convergence. The unexpected presence of a palisade endocarp could be a symplesiomorphy of the sister orders Magnoliales and Laurales or a synapomorphy of some Magnoliales and some Laurales.
... Here we follow published hypotheses on a case-by-case basis. For example, we treat the epicalyx of Malvaceae and the calyptra of Eupomatia as bracts 16,17 , but the pair of deciduous organs enclosing the bud in Papaver as outer perianth organs 18,19 . ...
... It consists of three carpels in Clematoclethra, Saurauia p.p., Roridula and Heliamphora, typically five carpels in Saurauia p.p., Darlingtonia and Sarracenia, or typically > 15 carpels in Actinidia (Soejarto, 1980; Li et al., 2007; L€ ofstrand & Sch€ onenberger, 2015a). Studies of floral development have helped to clarify many controversial interpretations of floral structures (e.g. the calyptra of Eupomatiaceae: Endress, 2003; the perianth of Penaeaceae: Sch€ onenberger & Conti, 2003; the androecium of Malvaceae: von Balthazar et al., 2004 Balthazar et al., , 2006 ). In polystemonous flowers, a developmental study is the only way to determine unequivocally the organization of the androecium. ...
The early floral development of Actinidia (A. arguta, A. callosa, A. chinensis and A. kolomikta; Actinidiaceae), Saurauia (S. montana, S. oldhamii, S. pittieri and S. subspinosa; Actinidiaceae), Roridula gorgonias (Roridulaceae) and Heliamphora nutans (Sarraceniaceae) was studied comparatively using scanning electron microscopy. Late stages of androecium development are additionally presented for Clematoclethra scandens (Actinidiaceae), Darlingtonia californica and Sarracenia leucophylla (Sarraceniaceae). Flowers are typically pentamerous and share a number of developmental features: perianth organs emerge in a clockwise or anticlockwise spiral sequence on the floral apex with relatively long plastochrons between successive organs, resulting in conspicuous size differences among perianth organs in early development; the perianth always consists of two differentiated whorls (unlike earlier interpretations of the perianth in Heliamphora); the androecium is polystemonous in most species and is initiated with leading stamens in alternipetalous positions; successive stamen primordia appear in a lateral succession until a ring-like structure is formed; and the anthers become inverted shortly before anthesis. Later androecial development differs conspicuously between taxa and further proliferation may be centrifugal, centripetal and/or lateral. For Ericales, unusual features of floral development include: petals initiated in a spiral sequence (but later organized in a whorl) with comparatively long plastochrons between individual petals (except Saurauia); common occurrence of perianth organs in double positions in Actinidiaceae; and anthers that become inverted close to anthesis. The floral development in the sarracenioids is additionally compared with that of other families and clades in Ericales, further emphasizing the highly variable patterns of androecium development in the order.
... Protection of the bud is by a calyptra, an amplexicaul bract. The petal-like inner staminodes produce sticky, oily exudates and emit a strong, fruity-musky smell (Endress 2003, Kim et al. 2005. Anthesis lasts one day in E. laurina, which has cream-colored flowers, and two days in E. bennettii, which has yellow flowers and innermost staminodes that are purple. ...
An updated description of the pollination and reproductive biology of basal angiosperms is given to
show their principal associations with pollinating agents. The review considers members of the
ANITA grade, as well as some basal monocots, the magnoliids, Chloranthaceae and Ceratophyllaceae.
Morphological, physiological and behavioral characteristics of flowers and their pollinating insects
are evaluated. Based on current evidence, early-divergent angiosperms were and are pollination generalists,
even so there has been early specialization for either flies, beetles, thrips or bees. Although
there are many tendencies for development from generalist flowers to specialist ones, there are also
reversals with the development from specialist flowers to generalist ones. The earliest specialization
seems to be fly pollination. Adaptations to more recently evolved insect groups, such as scarab beetles
or perfume-collecting euglossine bees, demonstrate that several basal angiosperm lines were flexible
enough to radiate into modern ecological niches.
... Few studies have looked at the origin and function of the calyptra. Endress (2003) studied the origin of the calyptra in the family Eupomatiaceae, and suggested that perhaps the calyptra helps protect floral parts against pollinating weevils. Calyptrate species of Conostegia have typical buzz pollinated flowers with poricidal anthers (Buchman, 1983;Buchman and Hurley, 1978;Renner, 1989). ...
a b s t r a c t Conostegia has been traditionally defined to consist of 42 species in the tribe Miconieae. Recent phyloge-netic studies have cast doubt on the monophyly of the genus and highlighted the need for a phylogenetic study focused on Conostegia. The purpose of this study was to test the monophyly of Conostegia and address relationships in the genus. We addressed the evolutionary history of Conostegia using DNA sequences from six loci. Difficulty in finding discrete characters that support clades prompted an anatom-ical survey of leaves and flowers as well as the exploratory use of some continuous characters. We coded as many species as possible for fifteen characters. Lastly, field work was conducted to document floral traits at anthesis due to the poor quality of preservation of flowers on herbarium specimens. Conostegia was found to be paraphyletic and composed of three main clades. The historically important characters of a calyptrate calyx and pleiostemony were found to have evolved more than once inside the Conostegia clade. Several other characters were found to support the clades we identified. The most unusual charac-ters were mucilage inside the ovary which is here reported in the Melastomataceae for the first time, a stele inside the style which is mostly restricted to one clade of Conostegia and known only in this clade of the Melastomataceae, and herkogamy which has been lost in two clades within Conostegia. A combination of molecular phylogenetic analyses and broad morphological surveys allowed the better understanding of the evolutionary history in a clade of mostly cloud forest Neotropical trees. The need to include anatomical studies and tackle continuous characters is here demonstrated.
