02322nas a2200169 4500008004100000245012200041210006900163260003000232300001100262490000600273520173400279100002002013700002402033700002002057700002702077856004802104 2013 eng d00aFunctional Monoecy Due to Delayed Anther Dehiscence: A Novel Mechanism in Pseuduvaria mulgraveana (Annonaceae)0 aFunctional Monoecy Due to Delayed Anther Dehiscence A Novel Mech bPublic Library of Science ae599510 v83 a

Unlike most genera in the early-divergent angiosperm family Annonaceae, Pseuduvaria exhibits a diversity of floral sex expression. Most species are structurally andromonoecious (or possibly androdioecious), although the hermaphroditic flowers have been inferred to be functionally pistillate, with sterile staminodes. Pseuduvaria presents an ideal model for investigating the evolution of floral sex in early-divergent angiosperms, although detailed empirical studies are currently lacking. The phenology and pollination ecology of the Australian endemic species Pseuduvaria mulgraveana are studied in detail, including evaluations of floral scent chemistry, pollen viability, and floral visitors. Results showed that the flowers are pollinated by small diurnal nitidulid beetles and are protogynous. Pollen from both hermaphroditic and staminate flowers are shown to be equally viable. The structurally hermaphroditic flowers are nevertheless functionally pistillate as anther dehiscence is delayed until after petal abscission and hence after the departure of pollinators. This mechanism to achieve functional unisexuality of flowers has not previously been reported in angiosperms. It is known that protogyny is widespread amongst early-divergent angiosperms, including the Annonaceae, and is effective in preventing autogamy. Delayed anther dehiscence represents a further elaboration of this, and is effective in preventing geitonogamy since very few sexually mature flowers occur simultaneously in an individual. We highlight the necessity for field-based empirical interpretations of functional floral sex expression prior to evaluations of evolutionary processes.

1 aPang, Chun-Chiu1 aScharaschkin, Tanya1 aSu, Yvonne, C F1 aSaunders, Richard, M K uhttps://annonaceae.myspecies.info/node/539802387nas a2200253 4500008004100000020001400041245017000055210006900225300001200294520156400306653001801870653002401888653001501912653001501927653001301942100001401955700001501969700001401984700002201998700002002020700001802040700002702058856004802085 2013 eng d a1759-683100aReassessing the taxonomic status of two enigmatic Desmos species (Annonaceae): Morphological and molecular phylogenetic support for a new genus, Wangia0 aReassessing the taxonomic status of two enigmatic iDesmos ispeci an/a-n/a3 aThe systematic position of two enigmatic Annonaceae species from China, Desmos saccopetaloides and Desmos yunnanensis, has been controversial, with both species having been transferred between several different genera within subfamilies Annonoideae and Malmeoideae. Phylogenetic analyses of eight chloroplast regions (matK, ndhF, ndhF-rpl32, psbA-trnH, rbcL, rpl32-trnL, trnL-F, and ycf1; ca. 9.2 kb, 66 taxa) unambiguously placed D. saccopetaloides in a subclade of tribe Miliuseae, nested among the genera Monoon, Neo-uvaria, Phaeanthus, Sageraea, and Stelechocarpus. This relationship was also supported by endosperm rumination patterns in the seed; other morphological characters furthermore indicated that D. saccopetaloides has closer affinities with Monoon, Neo-uvaria, and Phaeanthus rather than either Sageraea or Stelechocarpus. Desmos saccopetaloides is distinguished from these genera by its leaf-opposed inflorescences, sepaloid outer petals, saccate inner petals with basal glandular tissue, moniliform monocarps with uniseriate seeds, and rectangular disulculate pollen with two “cryptoapertures”. On the basis of the combined molecular phylogenetic and morphological data, we propose a new genus, Wangia, to accommodate D. saccopetaloides. The molecular phylogenetic analyses furthermore indicated that Desmos yunnanensis belongs to the genus Dasymaschalon: examination of the type collections revealed that it is conspecific with Dasymaschalon obtusipetalum, although the combination Dasymaschalon yunnanense has nomenclatural priority.10aDasymaschalon10amolecular phylogeny10amorphology10aPhaeanthus10ataxonomy1 aGuo, Xing1 aWang, Jing1 aXue, Bine1 aThomas, Daniel, C1 aSu, Yvonne, C F1 aTan, Yun-Hong1 aSaunders, Richard, M K uhttps://annonaceae.myspecies.info/node/5147