Gracilaria usneoides (C.Agardh) J.Agardh

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

Gracilaria usneoides (C.Agardh) J.Agardh

Thallus cartilaginous, dark red or greenish, 7–28 cm long, with cylindrical axes in cross section, 560–1100 μm in diameter. Main axes branching pseudo-dichotomously, laterally or irregularly; branches without constrictions and with smooth surfaces ( Fig. 51 ). Pseudoparenchymatous organization with a gradual transition between medulla and cortex ( Fig. 52 ). Medulla with 8–12 layers of irregular cells, 80–140 μm x 120–290 μm in diameter. Subcortex with three layers of rounded cells, 35–50 μm in diameter. Cortex with 1-2 layers of ovoid cells, pigmented, 4–7 μm x 6–10 μm in diameter. Cystocarps without constrictions at the base, 720–840 μm x 1200 –1600 μm in diameter ( Fig. 53 ).

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.