Gracilaria microcarpa Dreckmann, Núñez-Resendiz & Sentíes

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 microcarpa Dreckmann, Núñez-Resendiz & Sentíes

Thallus cartilaginous, dark red, 8–22 cm in length, with cylindrical axes in cross section, 270–410 μm in diameter. Main axes and branches branching dichotomously, sometimes the last branches branching trichotomously; branches without constrictions, with smooth surfaces and dichotomous or acute apices ( Fig. 46 ). Pseudoparenchymatous organization, with an abrupt transition between medulla and cortex ( Fig. 47 ). Medulla with 8–9 layers of isodiametric to irregular cells, 30–105 μm x 40–110 μm in diameter. Subcortex with one layer of rounded cells, 5.5–10 μm x 7–17 μm in diameter. Cortex with 2–3 layers of small and pigmented cells, 4–7 μm x 2–3.5 μm in diameter. Cystocarps notoriously smaller than in other species within the genus, 155–170 μm x 280–300 μm in diameter, conspicuously constricted at the base ( Fig. 48 ).

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.