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Sagaria cilentana gen. et sp. nov. A new Angiosperm Fructification from the Middle Albian of Southern Italy
No full textA single specimen of a new fossil angiosperm, Sagaria cilentana gen. et sp. nov., has been recovered from
limestones of the ‘‘plattenkalk’’ of the Middle Albian at Monti Alburni, near Petina, Campania, Italy.
Associated fossils include Pagiophyllum sp., Podozamites sp. and Zamites sp. The angiosperm has a main
axis approximately 8 cm long with three attached leaves and a distal cyme bearing three fructifications.
The fructifications display divided distal tips indicating three - four lobes. Four cm from the base,
underneath the main axis, there is a lobed structure, presumably a leaf. An unattached leaf near the
specimen is in a position that suggests that it comes from the same plant. The leaf has an elongate
petiole, obtuse base and on the right side of the lamina are three lobes. Affinities are uncertain but show
similarities in overall morphology to basal eudicots, especially Ranunculaceae
The carboniferous paleobotanical collection of the �Centro Caprense Ignazio Cerio� (Capri, Italy): a taxonomic revision
No full textstampato a settembre 200
STOMATAL DEVELOPMENT IN AERIAL AXES OF PSILOTUM NUDUM (PSILOTACEAE)
No full textApical regions of developing aerial shoots of Psilotum nudum (L.) Beauv. were studied using both scanning electron microscopy (SEM) and light microscopy (LM) with the aim of improving our understanding of early stages in stomatal and epidermal ontogenesis. SEM samples were fixed in gluteraldehyde, critical point dried, and coated with an Au-Pd alloy. LM samples were fixed in FAA and embedded in paraffin. LM sections were stained with 0.05% toluidine blue for protein. SEM shows that P. nudum stomata develop from 20 gm-long domed meristemoid cells into guard cell mother cells (GMCs). A furrow dividing guard cells develops at 30 mu m long, and wax deposition that will cover the entire cell begins at 70 mu m long. LM longitudinal sections of GMCs show a cytoplasmic protein net that organizes into radial fibers, similar to reports of actin fibers in stomata of angiosperms. This study provides additional details of stomatal development in Psilotum and is the first report of an actin-like protein net in Psilotum
I nuovi allestimenti nella Sezione di Paleobotanica del Museo dell?Orto Botanico di Napoli
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