Gracilariopsis tenuifrons (C.J.Bird & E.C.Oliveira) Fredericq & Hommersand

Resendiz, María Luisa Núñez, Dreckmann, Kurt M., Sentíes, Abel, Wynne, Michael J. & Tejera, Hilda León, 2019, Marine red algae (Rhodophyta) of economic use in the algal drifts from the Yucatan Peninsula, Mexico, Phytotaxa 387 (3), pp. 219-240 : 233

Gracilariopsis tenuifrons (C.J.Bird & E.C.Oliveira) Fredericq & Hommersand

Thallus cartilaginous, filiform, tangle-like, olive green or dark to red purple, 20–30 cm in length, with cylindrical axes in cross section, 530–740 μm in diameter. Main axes branching dichotomous; branches without constrictions, smooth surfaces and acute apices ( Fig. 54 ). Pseudoparenchymatous organization, with a gradual transition between medulla and cortex ( Fig. 55 ). Medulla with 6–8 layers of rounded cells, remarkably variable in size with those of the center having the largest size, 70–230 μm in diameter. Subcortex with two layers of elongated cells, pigmented, 15–25 μm in diameter. Cortex with two layers of spherical cells, 8–12 μm in diameter.

Figures

FIGURES 51–64. 51–53. Gracilaria usneoides. 51. Habit. Scale bar = 3 cm. 52. Medullary and cortical cells. Scale bar = 260 μm. 53. Mature cystocarp. Scale bar = 420 μm. 54–55. Gracilariopsis tenuifrons. 54. Habit. Scale bar = 4 cm. 55. Medullary and cortical cells. Scale bar = 170 μm. 56–58. Codiophyllum sp. 56. Habit. Scale bar = 4 cm. 57. Apices with small ligules. Scale bar = 5 cm. 58. Medullary filaments and cortical cells. Scale bar = 120 μm. 59–61. Halymenia pseudofloresii. 59. Habit. Scale bar = 4 cm. 60. Medullary filaments and cortical cells. Scale bar = 460 μm. 61. Tetrasporangium in cortex. Scale bar = 40 μm. 62–64. Botryocladia occidentalis. 62. Habit. Scale bar = 4 cm. 63. Medullary and cortical cells in cylindrical axes. Scale bar = 300 μm. 64. Medullary and cortical cells in globular branches. Scale bar = 150 μm.