02367nas a2200301 4500008004100000245011900041210006900160300001200229490000800241520150700249653001201756653002001768653001001788653001101798653001001809653001801819653001601837653001301853653001001866653002101876653001001897653001601907100002501923700001901948700002401967700002401991856005002015 2013 eng d00aMorphology of Maundia supports its isolated phylogenetic position in the early-divergent monocot order Alismatales0 aMorphology of Maundia supports its isolated phylogenetic positio a12–450 v1733 a

According to recent molecular phylogenetic data, the rare Australian endemic Maundia triglochinoides does not form a clade with taxa traditionally classified as members of Juncaginaceae. Therefore, views on the morphological evolution and taxonomy of Alismatales require re-assessment. As the morphology of Maundia is poorly known and some key features have been controversially described in the literature, the flowers, fruits, inflorescence axes and peduncles were studied using light and scanning electron microscopy. Inflorescences are bractless spikes with flowers arranged in trimerous whorls. Except in the inflorescence tip (where the flower groundplan is variable), flowers possess two tepals in transversal-abaxial positions, six stamens in two trimerous whorls and four carpels in median and transversal positions. Fruits are indehiscent. The shared possession of orthotropous ovules supports the molecular phylogenetic placement of Maundia as sister to a large clade including Potamogetonaceae and related families. Maundia and Aponogeton spp. share the same highly unusual floral groundplan, a homoplastic similarity that can be explained by spatial constraints in developing inflorescences. The nucellar coenocyte of Maundia appears to be unique among monocots. As Maundia exhibits a mosaic of features characteristic of other families of tepaloid core Alismatales, its segregation as a separate family is plausible.

10aanatomy10aAponogetonaceae10abract10aflower10afruit10aJuncaginaceae10aMaundiaceae10anucellus10aovule10aPotamogetonaceae10atepal10avasculature1 aSokoloff, Dmitry, D.1 aMering, Sabine1 aJacobs, Surrey, W L1 aRemizowa, Margarita uhttps://juncaginaceae.myspecies.info/node/58802733nas a2200157 4500008004100000245017900041210006900220300001200289490000800301520204500309653010502354100002402459700002102483700002102504856005002525 2005 eng d00aEvolutionary transitions among flowers of perianthless Piperales: inferences from inflorescence and flower development in the anomalous species Peperomia fraseri (Piperaceae)0 aEvolutionary transitions among flowers of perianthless Piperales a925-9430 v1663 aFloral and inflorescence structure and ontogeny are described in detail in Peperomia fraseri, an anomalous species of Piperaceae that differs in several respects from other species of Peperomia and other perianthless Piperales (Piperaceae and Saururaceae). Inflorescence structure is atypical in this species, with numerous spikes arranged spirally on a long raceme. There is a gender distribution of flowers along each spike, with the proximal (lower) part bearing bisexual flowers and the distal (upper) region bearing female flowers. Furthermore, there is a high degree of polymorphism in the structure (including presence or absence) of flower-subtending bracts in the same inflorescence. Bract suppression at the basalmost abaxial position in P. fraseri could be explained by a strong inhibitory activity of the spike-subtending bract or its primordium. Bract suppression among scattered flowers in the lower (bisexual) region is interpreted as an example of somatic instability. By contrast, more distal bract and stamen suppression seems to be part of a general tendency to flower reduction toward the spike apex in P. fraseri, where spatial constraints in the inflorescence control the size and shape of the bract and floral primordia, resulting in stamen suppression in smaller primordia. However, it is difficult to understand why an abracteate flower is formed in P. fraseri rather than a sterile bract, as in Peperomia hispidula. Furthermore, in contrast with most other Piperaceae, P. fraseri has no apical residuum on mature spikes; at least some partial inflorescences bear a terminal flowerlike structure, although this more closely resembles those of some Saururaceae than the "true" terminal flower of perianth-bearing Piperales, such as Aristolochiaceae. Peperomia fraseri and other atypical members of Piperaceae represent potentially useful models for examination of patterns of bract and stamen loss in perianthless Piperales, in which spatial constraints in the developing spike are important for floral construction.10abasal angiosperms, bract, floral evolution, ontogeny, Piperales, stamen suppression, terminal flower1 aRemizowa, Margarita1 aRudall, Paula, J1 aSokoloff, Dmitry uhttps://juncaginaceae.myspecies.info/node/30002347nas a2200157 4500008004100000245011400041210006900155300001400224490000700238520171700245653011101962100002102073700002102094700002402115856005002139 2006 eng d00aFlower-like terminal structures in racemose inflorescences: a tool in morphogenetic and evolutionary research0 aFlowerlike terminal structures in racemose inflorescences a tool a3517-35300 v573 aTerminal flower-like structures (TFLS) occur in many angiosperms that possess indeterminate inflorescences such as spikes, racemes, or spadices. We describe and review TFLS in early-divergent angiosperms, especially the magnoliid order Piperales and the monocot order Alismatales, in which floral interpretation is controversial. Essentially similar TFLS occur in a wide range of taxa. Among magnoliids, they occur in some Piperales (Saururaceae and a few Piperaceae), but are absent from Chloranthaceae. Among monocots, they occur in some early-divergent families such as Acoraceae, Aponogetonaceae, Juncaginaceae, Potamogetonaceae, and Ruppiaceae. Similar TFLS with obscure organ identity are recorded in mutants of Arabidopsis. TFLS can often be interpreted as pseudanthia (close aggregations of reduced flowers), but in some cases the entire terminal pseudanthium is very similar to a true flower. In some cases, elaborated TFLS could therefore have given rise to what are normally termed ムtrueメ (i.e. euanthial) flowers. Data presented here on terminal pseudanthia in Potamogeton and Ruppia support a pseudanthial evolutionary origin of reproductive units in the alismatid families Zannichelliaceae and Cymodoceaceae. Furthermore, in some alismatid species, either the entire inflorescence apex or an individual primordium at or near the inflorescence tip can be transformed into a filamentous or tubular (or intermediate) structure. A tubular structure enclosing stamens and carpels is described in Piper. This indicates that pseudanthium formation can provoke morphological novelties, perhaps due to new patterns of overlap between expression zones of regulatory genes and/or new spatial constraints. 10aAlismatales, development, flower, inflorescence, organ identity, Piperales, pseudanthium, regulatory genes1 aSokoloff, Dmitry1 aRudall, Paula, J1 aRemizowa, Margarita uhttps://juncaginaceae.myspecies.info/node/322