Gracilaria Greville 1830

Gurgel, Carlos Frederico D., Norris, James N., Schmidt, William E., Le, Hau Nhu & Fredericq, Suzanne, 2018, Systematics of the Gracilariales (Rhodophyta) including new subfamilies, tribes, subgenera, and two new genera, Agarophyton gen. nov. and Crassa gen. nov., Phytotaxa 374 (1), pp. 1-23 : 4-6

Gracilaria Greville 1830 :iiv, 121

GENERITYPE: Gracilaria bursa-pastoris (S.G. Gmelin) P.C. Silva (1952: 265)

BASIONYM: Fucus bursa-pastoris S.G. Gmelin 1768: 121 . Note: the conserved generitype is Gracilaria compressa (C. Agardh) Greville (1830: 121) ; basionym: Sphaerococcus compressus C. Agardh (1822: 308) , but see Steentoft et al. (1991: 633), Silva (1994: 263), and Silva et al. (1996: 917).

PERTINENT SYNONYMS: Congracilaria Yamamoto , Gracilariophila Setchell et H.L.Wilson (in part), Gracilariocolax Weber-van Bosse.

TYPE LOCALITY: Cádiz, Iberian Peninsula, southwestern Spain.

DIAGNOSIS: Tetrasporangia superficial, in both unmodified cortex or in sori. Spermatangial conceptacles of the shallow cortical type only (i.e., textorii - type or the verrucosa - type sensu Yamamoto 1975, 1978, 1984). Gonimoblast filaments consisting of vacuolated cells in center towards the base, becoming elongated and highly branched towards the outside and bearing carposporangia in branched chains, the carposporangia cut off by oblique division with the carpospores terminal, maturing basipetally; tubular nutritive cells numerous, variable in diameter, connecting to outer pericarp, initially fusing with single pericarp cell that may fuse progressively with neighboring pericarp cells, extending the length of the tubular nutritive cells to form a tube-shaped pericarp fusion cell that sometimes leaves behind remnant pit connections; carpogonial fusion cell with numerous enlarged nuclei, extending moderately through fusion with adjoining inner pericarp cell, becoming embedded longitudinally in the inner pericarp; cystocarp cavity formed schizogenously as the gonimoblasts grow by the dissolution of pit connections between inner and outer gonimoblast filaments; inner pericarp composed of straight cell rows, five to seven cells long, in which each cell contains an enlarged nucleus; fusion cell persisting or disintegrating at the mature stages of cystocarp development.