Floral Development in the Nymphaeales

Doyle

2015

TAXON

New morphological and phylogenetic data prompt us to present an updated review of floral morphology and its evolution in the basal ANITA grade of living angiosperms, Chloranthaceae, and Ceratophyllum. Floral phyllotaxis is complex whorled in Nymphaeales and spiral in Amborella and Austrobaileyales. It is unresolved whether phyllotaxis was ancestrally whorled or spiral, but if it was whorled, the whorls were trimerous. The flowers are probably ancestrally bisexual because in most families with unisexual flowers these flowers exhibit rudiments of the opposite sex. Carpels are largely ascidiate and the closure line is short, either transverse or longitudinal. A style is usually absent or, if present, generally short and not plicate. Angiospermy (carpel sealing) is by secretion, rather than postgenital fusion, except in large‐flowered Nymphaeales and in Illicium, correlated with unusual fruits. Carpels with a single, median, pendent ovule are probably plesiomorphic. Chloranth‐ aceae and Ceratophyllaceae have an unsettled phylogenetic position, but in some phylogenetic analyses they form a clade, which may be sister to the remaining mesangiosperms (Magnoliidae, monocots, eudicots). This position is supported by their carpel characters, which are similar to those of the ANITA grade and different from those of most other mesangiosperms.

Section: Ancestral Traits Of (Living) Angiosperms (Figs 2-7)mentioning

confidence: 99%

Section: Version Of Recordmentioning

confidence: 99%

Ancestral traits and specializations in the flowers of the basal grade of living angiosperms

Doyle

2015

TAXON

“…In Brasenia, instead of having a simple papillate epidermis, the upper surface is covered with spherical (roundish) tricellular hairs. In Nymphaeaceae, the tepals are in several commonly tetramerous whorls (rarely trimerous or pentamerous whorls; Conard 1905;Schneider et al 2003); tepal number of the inner whorls is increased by double positions (Endress 2001) and is from four to eight in forms of Ondinea, up to more than 50 in Nymphaea, and more than 70 in Victoria (Schneider and Williamson 1993). They are spreading (upright in Nuphar).…”

Section: Results and Comparative Analysismentioning

confidence: 99%

“…Phyllotaxis of perianth organs in Nymphaeales is basically whorled (Endress 2001;Schneider et al 2003). In Nuphar, the onset of tepal initiation may be in a spiral sequence.…”

Section: Tepal Phyllotaxismentioning

confidence: 99%

“…Perianth phyllotaxis is diverse : spiral in Amborella (Endress and Igersheim 2000) and Austrobaileyales (Endress 1980b(Endress , 1983(Endress , 2001Endress and Sampson 1983;Tucker and Bourland 1994) and largely whorled in Nymphaeales (Endress 2001;Schneider et al 2003). Diverse phyllotaxis patterns commonly appear to be functionally linked with different aestivation patterns in angiosperms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Perianth Biology in the Basal Grade of Extant Angiosperms

International Journal of Plant Sciences

2008

Perianth structure and behavior were studied comparatively in representatives of all families of the basalmost extant angiosperms (ANITA grade plus Chloranthaceae). In addition, data from the literature were reviewed. Tepal aestivation is spiral imbricate in Amborella and Austrobaileyales, with broadly overlapping flanks; aestivation is mainly contort within each of the two tepal whorls in Cabomba (but open within each whorl and imbricate only between whorls in Brasenia) and is whorled imbricate in Nymphaeaceae. Tepals are absent in Hydatellaceae, Chloranthaceae (other than Hedyosmum), and Ceratophyllaceae. In two genera of Nymphaeales (Cabomba and Nuphar), nectaries are present on inner tepals. Tepals are caducous during or at the end of anthesis in Austrobaileyales. Preformations of the tepal abscission zone in flowers with caducous tepals include a narrow tepal base, constriction as seen in median longitudinal sections, and small-celled tissue. In contrast, the perianth organs of Amborella, Nymphaeales, and Chloranthaceae are not caducous and are associated with a broad tepal base without indentation and often without small-celled tissue. Only in the latter groups are there genera with basally united tepals (Amborella, Cabomba, and Hedyosmum). Perianth structure and behavior were studied comparatively in representatives of all families of the basalmost extant angiosperms (ANITA grade plus Chloranthaceae). In addition, data from the literature were reviewed. Tepal aestivation is spiral imbricate in Amborella and Austrobaileyales, with broadly overlapping flanks; aestivation is mainly contort within each of the two tepal whorls in Cabomba (but open within each whorl and imbricate only between whorls in Brasenia) and is whorled imbricate in Nymphaeaceae. Tepals are absent in Hydatellaceae, Chloranthaceae (other than Hedyosmum), and Ceratophyllaceae. In two genera of Nymphaeales (Cabomba and Nuphar), nectaries are present on inner tepals. Tepals are caducous during or at the end of anthesis in Austrobaileyales. Preformations of the tepal abscission zone in flowers with caducous tepals include a narrow tepal base, constriction as seen in median longitudinal sections, and small-celled tissue. In contrast, the perianth organs of Amborella, Nymphaeales, and Chloranthaceae are not caducous and are associated with a broad tepal base without indentation and often without small-celled tissue. Only in the latter groups are there genera with basally united tepals (Amborella, Cabomba, and Hedyosmum). PERIANTH BIOLOGY IN THE BASAL GRADE OF EXTANT ANGIOSPERMS

Ancestral traits and specializations in the flowers of the basal grade of living angiosperms

Doyle

2015

Taxon

New morphological and phylogenetic data prompt us to present an updated review of floral morphology and its evolution in the basal ANITA grade of living angiosperms, Chloranthaceae, and Ceratophyllum. Floral phyllotaxis is complex whorled in Nymphaeales and spiral in Amborella and Austrobaileyales. It is unresolved whether phyllotaxis was ancestrally whorled or spiral, but if it was whorled, the whorls were trimerous. The flowers are probably ancestrally bisexual because in most families with unisexual flowers these flowers exhibit rudiments of the opposite sex. Carpels are largely ascidiate and the closure line is short, either transverse or longitudinal. A style is usually absent or, if present, generally short and not plicate. Angiospermy (carpel sealing) is by secretion, rather than postgenital fusion, except in largeflowered Nymphaeales and in Illicium, correlated with unusual fruits. Carpels with a single, median, pendent ovule are probably plesiomorphic. Chloranth aceae and Ceratophyllaceae have an unsettled phylogenetic position, but in some phylogenetic analyses they form a clade, which may be sister to the remaining mesangiosperms (Magnoliidae, monocots, eudicots). This position is supported by their carpel characters, which are similar to those of the ANITA grade and different from those of most other mesangiosperms.