Gelidium rodrigueziae Quiroz-González et Ponce-Márquez

3.2.1 Gelidium rodrigueziae Quiroz-González et Ponce-Márquez

Holotype: Playa Hermosa , Veracruz, México (18°39 ′ 51 ″ y 95°7 ′ 48 ″ O). Thalli was growing on the shell of gastropod Stramonita rustica in the intertidal zone: GM 898 , vegetative, deposited in the Herbarium of Facultad de Ciencias , Universidad Nacional Autónoma de México ( FCME); collected by L. G. Aguilar-Estrada on 18 May 2018. GenBank accession number OQ850753 (rbc L) and OR133600 (COI-5 P) . Isotype: GM 899 . GenBank accession number OQ850754 (rbc L) and OR133601 (COI-5 P). Paratypes: Faro Verde , Veracruz, México GM900 , GM 901 deposited in the Herbarium of Facultad de Ciencias , Universidad Nacional Autónoma de México ( FCME); collected by N . Quiroz-González on 13 May 2022. GenBank accession number OQ850755, OQ850756 (rbc L) and OR133602, OR133603 (COI-5 P) .

Etymology: Dedicated to Dra. DenÍ Rodriguez a Mexican phycologist, for her invaluable contribution to our knowledge of the Gelidiales from Mexico and the world.

Diagnosis: Thallus light to dark red, up to 0.7 cm high, forming a turf on Stramonita rustica ( Figure 4A and B View Figure 4 ), with terete prostrate branches attached by brush-like holdfasts ( Figure 4C and D View Figure 4 ). Erect axes cylindrical at the base and flattened above 150 – 350 µm in width. Branches are rare, and when branches are occasionally present, they are irregularly arranged with one order of ramification ( Figure 4B – D View Figure 4 ).

Description: Plants a turf of purple-red thalli, with cylindrical prostrate axes attached to substratum with brush-like haptera ( Figure 5A View Figure 5 ) and erect linear to clavate axes, with irregular to smooth margins, cylindrical at base, 0.3 – 0.7 cm high and 150 – 350 µm in width ( Figure 4B – D View Figure 4 ). Axes in transverse section are ovoid, and elliptical. The shape of vegetative apices is acute ( Figure 5B View Figure 5 ). Cortex of 1 – 2 layers of rounded cells, 3.75 – 4.5 µm in diameter ( Figure 5C and D View Figure 5 ), outer cortical cells irregularly arranged in surface view. Medulla of 2 – 4 rows of circular or subcircular cells in transverse section, 10 – 12.5 μm in diameter, and with very large intercellular spaces. Internal rhizoidal filaments in the medulla ( Figure 5C and D View Figure 5 ).

Additional material examined: Playa Hermosa, Veracruz, México GM 902 - GM905 and GM911 - GM922 vegetative, deposited in the Herbarium of Facultad de Ciencias, Universidad Nacional Autónoma de México ( FCME); collected by L. G. Aguilar-Estrada on 18 May 2018 . Faro Verde , Veracruz, México GM 906-GM 908 and GM 923-GM 926 vegetative, deposited in the Herbarium of Facultad de Ciencias, Universidad Nacional Autónoma de México ( FCME); collected by N. Quiroz-González on 13 May 2022 . Andrés Sánchez Magallanes Breakwater , Tabasco, México GM 909-GM910, GM 927 vegetative, deposited in the Herbarium of Facultad de Ciencias, Universidad Nacional Autónoma de México ( FCME); collected by L. G. Aguilar-Estrada on 16 May 2022 .