Ericaria giacconei Serio & G.Furnari, sp. nov.

(Figs 2-5)

Thalli caespitose, attached to the substrate by a robust and compact basal disc (3-5 cm in diameter) from which 4-20 cauloids, cylindrical, up to 30 cm high and 3-5 mm in diameter, arise; apex of cauloids smooth, not prominent, never surrounded by spiniform appendages, sometimes surrounded by short cylindrical non-spiny young primary branches; primary branches cylindrical, bearing branches of higher order cylindrical, and with subequal development that give the thallus a cupressoid habit; tophules and aerocysts absent; in cross section, medulla formed by small rounded cells, cortex made of roundish cells with thin walls and meristoderm formed by a layer of rectangular cells twice longer than wide; receptacles terminal, cylindrical-ovoid to clavate, 0.5-1 cm long and 1-2 mm wide, with grouped conceptacles; conceptacles bisexual, subspherical, located at the base of spinous deciduous appendages; oogonia occupying the floor of the conceptacle and antheridia on branched hairs.

HOLOTYPE. — Italy, Straits of Sicily, Porto Palo di Capo Passero, Contrada Guardiana, 36°39’03”N, 15°04’37”E, 0.50 m depth, 11.I.2020, fertile specimen, coll. Serio, (CAT [CAT 2716] (Figs 3, 4).

ISOTYPE. — Same data of the holotype; CAT [CAT 2717, CAT 2718]).

E TYMOLOGY. — The specific epithet honours Professor Giuseppe Giaccone, who first found this species, for his significant contributions to the study of the Cystoseira complex.

TYPE LOCALITY. — Porto Palo di Capo Passero (Sicily, Italy), 36°39’03”N, 15°04’37”E.

DISTRIBUTION. — Type locality; Punta D’Aliga (Sicily, Italy) (Giaccone 1986 as C. hyblaea); Isola delle Correnti (Sicily, Italy) (Pizzuto 1999 as C. crinita); Kelibia (Tunisia) (Bouafif et al. 2016 as C. hyblaea) (Fig. 1).

HABITAT. — Plants living on semi-exposed rocky shores at 0.2- 1.0 m depth. Species vicariant of E. amentacea (Giaccone, 1986 as C. amentacea).

REMARKS

Other figures (as “ C. hyblaea ”): Giaccone (1986, figs 1, 2), Cormaci et al. (2012, pl. 111, figs 1-3), Bouafif et al. (2016, figs 21-24).