Halimeda discoidea

Halimeda discoidea Decaisne

Halimeda discoidea Decaisne, 1842b:102; Collins, 1909b:400; Howe, 1911:492; Setchell and Gardner, 1920b:177, pl. 13: fig. 3; Setchell and Gardner, 1924a:704; Dawson, 1944:214; Taylor, 1945:73; Dawson, 1949:244, 245; Taylor, 1950:85, pl. 45: fig. 1; Dawson, 1957b:9; Dawson, 1959a:4, 6, 8, 18; Hillis, 1959:352, pl. 2: fig. 5, pl. 5: fig. 11, pl. 6: fig. 11, pl. 7: figs. 9, 10, pl. 8: figs. 5–8, pl. 11; Dawson, 1960c:97; Dawson et al., 1960b:13, 14; Dawson, 1961b:382; Dawson, 1961c:406, pl. 7: fig. 1; Dawson, 1962b:177, 229, fig. 22; Huerta-Múzquiz, 1978:338; Hillis-Colinvaux, 1980:136, fig. 41; Pedroche and González-González, 1981:64; González-González, 1993:443; Huerta-Múzquiz and Mendoza-González, 1985:44; Salcedo-Martínez et al., 1988:82; Sánchez-Rodríguez et al., 1989:39; Mateo-Cid and Mendoza-González, 1991:25; Rocha-Ramírez and Siqueiros-Beltrones, 1991:24; Martínez-Lozano et al., 1991:22; Tsuda and Kamura, 1991:69, pl. 4: fig. 1; Mateo-Cid and Mendoza-González, 1992:25; León-Tejera et al., 1993:199, 202; Servière-Zaragoza et al., 1993:482; Mateo-Cid and Mendoza-González, 1994b:45; León-Tejera and González-González, 1994:26; González-González et al., 1996:287; Bucio-Pacheco and Dreckmann, 1998:43, 45; Yoshida, 1998:114; Hillis et al., 1998:671; Mendoza-González and Mateo-Cid, 1998:26; Servière-Zaragoza et al., 1998:169, 179; Rodríguez-Morales and Siqueiros-Beltrones, 1999:22; López et al., 2000:339; Paul-Chávez and Riosmena-Rodríguez, 2000:146; Abbott and Huisman, 2004:131, fig. 49B–E; López et al., 2004:10; Wysor, 2004:225; Hernández-Herrera et al., 2005:146; Pedroche et al., 2005:80;

Riosmena-Rodríguez et al., 2005:101; Servière-Zaragoza et al., 2007:7; Pacheco-Ruíz et al., 2008:202.

Algae forming small clumps of subdichotomously to trichotomously branched fronds (branching in several planes), up to 10 cm high; of lightly to moderately calcified flat segments that alternate with very short noncalcified joints of entangled medullary filaments fused in pairs (rarely 3); attached below by a single, relatively small, mass of rhizoidal filaments. Flat segments variable in shape, mostly obovate to reniform, and 1.0–2.5 cm wide; upper segments usually flexible, leathery. Surface utricles forming hexagonal pattern in surface view; cup-shaped in transection, 25–45 µm in diameter; laterally adherent to adjacent surface utricles (even after decalcification) along their distal margins for 15–20 µm; borne on notably larger, inflated secondary internal utricles, 60–175 µm in diameter.

HABITAT. On rocks, and in crevices and tide pools; low intertidal to shallow subtidal.

DISTRIBUTION. Gulf of California: Puerto Refugio, Isla Ángel de la Guarda; Isla Partida; Guaymas to San Jose del Cabo. Pacific coast: Isla Socorro and Isla Clarion (Islas Revillagigedo); Isla Magdalena (southwest of Punta Entrada, Bahía Magdalena, Baja California) to Costa Rica; Panama; Hawaiian Islands; Bikini Island; China; Japan.

TYPE LOCALITY. “Not certain” (Silva et al., 1996a). Although the herbarium label (PC) indicates it was collected “Kamtschatka” (Russia) during the voyage of the exploring ship Venus (Decaisne, 1842b:102), Hillis (1959:352; see also Hillis-Colvinaux, 1980) noted that “at least the locality [is] incorrect,” as waters of the Kamchatka Peninsula are far too cold for this tropical to subtropical species.

Halimeda discoidea is a species of calcareous green algae in the order Bryopsidales. It is commonly known as Money Plant due to its appearance and is usually found in the tropics.