The Fucales (Ochrophyta, Phaeophyceae) of the Island of Pantelleria (Sicily Channel, Mediterranean Sea): a new contribution Author Marletta, Giuliana Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche 60131 Ancona, Italy g.marletta@univpm.it Author Lombardo, Andrea Department of Biological, Geological and Environmental Sciences, University of Catania, 95124 Catania, Italy text Italian Botanist 2023 2023-06-15 15 137 163 http://dx.doi.org/10.3897/italianbotanist.15.103217 journal article http://dx.doi.org/10.3897/italianbotanist.15.103217 2531-4033-15-137 A0ED26AE219752299C11A734C6D0F79E Cystoseira compressa f. rosetta (Ercegovic) Cormaci, G. Furnari, Giaccone, B. Scammacca & Serio Fig. 4A, B Cystoseira compressa subsp. rosetta Ercegovic. Basionym. Cystoseira compressa subsp. rosetta Ercegovic. Synonym. Morphology of specimens from Pantelleria. This form is cespitose, with flattened habit, forming a rosette. It is attached to the substate by a small discoid holdfast. The apices are smooth. Primary branches are short (1-4 cm), strongly flattened and foliaceous. They are usually crossed by brownish transversal stripes. The branches are arranged with a distichous and alternating disposal. The cryptostomata are not very prominent and are disposed on longitudinal series. During the monitoring activity, we did not find fertile thalli of this form. Habitat. C. compressa f. rosetta occurred on wave-exposed coasts at Kattibuale, Gadir, Cala Tramontana, Martingana, Grotte Sataria, Kuddie Rosse and Arenella, in the upper infralittoral (0-1 m). Distribution. It is distributed in the whole Mediterranean Sea and along the North-West Atlantic, Bermudas Islands and East Atlantic, from Azores to Cape Verde ( Blanfune et al. 2022 ). Remarks. During the monitoring, thalli of this form were found isolated in shaded habitats, such as in small crevices between rocks. Figure 4. Cystoseira compressa f. rosetta A habit (the arrow indicates the thallus) B detail of primary branches with brownish transverse bands and cryptostomata disposed in longitudinal series.