Padina Adanson 1763
Creators: name: Pagana, Ilaria
name: Marroccia, Genny
name: Marletta, Giuliana
name: Alongi, Giuseppina
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Phaeophyceae
Dictyotales
Dictyotaceae
Padina

description: Key to the species of the genus Padina in the Mediterranean Sea.
1. Thallus with 2 layers of cells and/or a mixture of 2–3 layers of cells in the median portion ............................................................2
- Thallus with at least 3 layers of cells in the median portion ..............................................................................................................3
2. Thallus entirely composed of 2 layers of cells; hair lines are in concentric lines on the upper surface (ephemeral or absent in the lower surface); indusium absent................................................................................................................................ Padina boryana
- Thallus with a mixture of 2–3 cell layers in the median and basal portions; hair lines alternate on both surfaces; indusium present ......................................................................................................................................................................... Padina ditristromatica
3. Thallus with 3 layers of cells in the median portion and 3/ 4 in basal one; sporangial sori arranged in patches or in concentric lines; indusium present or absent .................................................................................................................................................................4
- Thallus with more than 3 layers of cells in the median and basal portion; sporangial sori arranged in continuous or discontinuous lines; indusium always absent ............................................................................................................................................................6
4. Thallus consisting entirely of 3 layers of cells except in the rolled apical portion; cells of the central layer and one cortical layer are more or less equal in height and usually smaller than the other cortical layer; sporangial sori arranged in concentric lines separated from each other by a sterile zone delimited by two consecutive hair lines on alternate surfaces of frond; indusium absent.............. .............................................................................................................................................................................. Padina boergesenii
- Thallus with 3 layers of cells in the median portion and 3/ 4 in basal ones; medullary layers (central layers) (1–2) consist of cells larger and less pigmented than the cells of the two peripheral layers; indusium present...................................................................5
5. Thallus with 3 layers of cells in the median portion and 3/ 4 in basal ones; sporangial sori arranged in continuous lines on both sides of the hair lines ......................................................................................................................................................... Padina pavonica
- Thallus with 3 layers of cells in both the median and basal portions; sporangial sori arranged in patches above hair line; indusium present................................................................................................................................................................. Padina pavonicoides
6. Thallus with 3–4 layers of cells in the median portion and 4 layers in the basal portion; sporangial sori present only on the lower surface arranged in continuous lines above the hair lines and discontinuous lines below the hair lines ....... Padina tetrastromatica
- Thallus with 3–4 layers of cells in the median portion and 6–8 layers of cells in the basal portion; sporangial sori present in both surfaces of the thallus arranged in more or less continuous lines ....................................................................... Padina gymnospora
description: Published as part of Pagana, Ilaria, Marroccia, Genny, Marletta, Giuliana & Alongi, Giuseppina, 2023, Re-examination of the distribution and species diversity of the genus Padina (Dictyotales, Phaeophyceae) in the Mediterranean Sea, pp. 205-218 in Phytotaxa 619 (3) on page 216, DOI: 10.11646/phytotaxa.619.3.1, http://zenodo.org/record/8426004