Sargassum lapazeanum

Sargassum lapazeanum Setchell et N. L. Gardner

Sargassum lapazeanum Setchell et N. L. Gardner, 1924a:734, pl. 20: fig.74; Setchell and Gardner, 1925:714; Dawson, 1944:243, pl. 34: figs. 1–34; Dawson, 1961b:400; Norris, 1973:7; Huerta Muzquiz, 1978:337; Huerta-Múzquiz and Mendoza-González, 1985:46; Mendoza-González and Mateo-Cid, 1986:421; Rocha-Ramírez and Siqueiros-Beltrones, 1990:18; Rocha-Ramírez and Siqueiros-Beltrones, 1991:26; Martínez-Lozano et al., 1991:23; Mateo-Cid et al., 1993:50; Phillips, 1995:118; González-González et al., 1996:161; Núñez-López and Casas-Valdez, 1997:19; Paul-Chávez and Riosmena-Rodríguez, 2000:137; Cruz-Ayala et al., 2001:190; Rivera and Scrosati, 2006:178; Rivera and Scrosati, 2008:45–49; Pacheco-Ruíz et al., 2008:205; Pedroche et al., 2008:96.

Sargassum bryantii Setchell et N. L. Gardner, 1924a:733, pl. 21: fig. 83.

Sargassum insulare Setchell et N. L. Gardner, 1924a:735, pl. 20: figs. 67, 68, pl. 21: fig. 78; Setchell and Gardner, 1925:717.

Erect axes, up to 1 m or more long, above a terete stipe, up to 2 cm long; with 5–7 terete, smooth primary branches from which several long, slender secondary branches arise; attached by a parenchymatous disc, formed by fusing of short haptera. Leaf-like blades, variable in shape, 5–20

mm long, with a short pedicel, without or sometimes with an inconspicuous midrib, and few to abundant conspicuous cryptostomata. Smallest blades more or less symmetrical with dentate margins; midsized blades asymmetrical, often as wide as long in midportions, with crenate to dentate lower margins and often smooth upper margins; upper blades symmetrical, larger, often widest toward apices, and with dentate margins. Vesicles among receptacles, spherical to subspherical, ellipsoidal, up to 2 mm long, usually with a short, small apical blade-like extension.

Receptacles intermixed with blades and vesicles; on short pedicel at base of a blade; spinulose, branched 2–3 times, up to 7 mm long.

HABITAT. On rocks; mid intertidal to shallow subtidal.

DISTRIBUTION. Gulf of California: Bahía San Francisquito to Cabo San Lucas.

TYPE LOCALITY. La Paz, Baja California Sur, Gulf of California.