Gelidium microdonticum W.R.Taylor, 1969

Jamas, Mayra, Iha, Cintia, Oliveira, Mariana C., Guimarães, Silvia M. P. B. & Fujii, Mutue T., 2017, Morphological and molecular studies on Gelidiaceae and Gelidiellaceae (Gelidiales, Rhodophyta) from Brazil with description of the new species Gelidium calidum, Phytotaxa 314 (2), pp. 195-218 : 206

Gelidium microdonticum W.R.Taylor

Figs. 5 E ; 7 G–K

Thalli in tufts forming carpets, vinaceous-red to darkened, up to 0.5 cm. Axes erect with serrated margin that are simple or sparingly and irregularly branched ( Fig. 5 E ). Apex obtuse with apical cell between two lobes ( Fig. 7 G ). Brush-like haptera. Many rhizines concentrated in medulla ( Fig. 7 H, I ). Tetrasporangia divided cruciate ( Fig. 7 J, K ).

Figures

FIGURE 5. Habit of the Gelidiaceae species. A–B. Gelidium crinale (A:SP469061, B:SP469067). Scale bar = 1 cm. C. Gelidium floridanum (SP469068). Scale bar = 2 cm. D. Gelidium lineare (SP469091). Scale bar = 1 cm. E. Gelidium microdonticum (SP469070). Scale bar = 0.5 cm.

FIGURE 7. A–F. Gelidium lineare. A. Detail of the apical portion showing the apical cell between two lobes (SP469087). Scale bar = 25 μm. B. Cross section of the middle region of the the main branch (SP469087). Scale bar = 100 μm. C. Detail of tetrasporangial branch (SP469091). Scale bar = 250 μm. D. Cross section of tetrasporangial branch, showing cruciately divided tetrasporangia (SP469091). Scale bar = 100 μm. E. Detail of male gametophyte branches, which may have more than one sorus per branch (SP469087). Scale bar = 500 μm. F. Cross section of male gametophyte branch, showing spermatia originated by transverse divisions (arrow) of elongated outer cortical cells (SP469087). Scale bar = 20 μm. G–K. Gelidium microdonticum (SP469070). G. Detail of the apical portion showing the apical cell between two lobes. Scale bar = 100 μm. H. Cross section of the middle region of the the main branch. Scale bar = 100 μm. I. Detail of the thallus, showing abundant rhizines in the medullary region. Scale bar = 250 μm. J. Tetrasporangial branch. Scale bar = 100 μm. K. Cross section of tetrasporangial branch, showing cruciately divided tetrasporangia. Scale bar = 100 μm.