Gracilaria tikvahiae McLachlan

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 tikvahiae McLachlan

Thallus delicate, cartilaginous, filiform, olive green, 12–23 cm long, with cylindrical axes in cross section, 630–780 μm in diameter. Main axes branching dichotomous or irregularly; branches without constrictions, covered with numerous marginal proliferations arranged alternately opposite or radially ( Fig. 49 ). Pseudoparenchymatous organization with a gradual transition between medulla and cortex ( Fig. 50 ). Medulla with 8–10 layers of rounded cells and variable diameter, 60–130 μm in diameter. Subcortex with two layers of spherical and pigmented cells, 20–38 μm in diameter. Cortex with 1–2 layers of ovoid cells, pigmented, anticlinal, 8–12 μm in diameter.

Figures

FIGURES 39–50. 39–41. Gracilaria cornea. 39. Habit. Scale bar = 4 cm. 40. Medullary and cortical cells. Scale bar = 250 μm. 41. Tetrasporangia in cortex. Scale bar = 30 μm. 42–43. Gracilaria flabelliformis. 42. Habit. Scale bar = 1.5 cm. 43. Medullary and cortical cells. Scale bar = 260 μm. 44–45. Gracilaria mammillaris. 44. Habit. Scale bar = 2 cm. 45. Medullary and cortical cells, and a mature cystocarp. Scale bar = 200 μm. 46–48. Gracilaria microcarpa. 46. Habit. Scale bar = 3 cm. 47. Medullary and cortical cells. Scale bar = 130 μm. 48. Mature cystocarp. Scale bar = 60 μm. 49–50. Gracilaria tikvahiae. 49. Habit. Scale bar = 2 cm. 50. Medullary and cortical cells. Scale bar = 130 μm.