Lithophyllum kaiseri (Heydrich) Heydrich (1897a: 412)

Basso, Daniela, Caragnano, Annalisa, Gall, Line Le & Rodondi, Graziella, 2015, The genus Lithophyllum in the north-western Indian Ocean, with description of L. yemenense sp. nov., L. socotraense sp. nov., L. subplicatum comb. et stat. nov., and the resumed L. affine, L. kaiseri, and L. subreduncum (Rhodophyta, Corallinales), Phytotaxa 208 (3), pp. 183-200 : 188-190

Lithophyllum kaiseri (Heydrich) Heydrich (1897a: 412)

Figures 4–5 ; Table 2

BASIONYM: Lithothamnion kaiseri Heydrich 1897b: 64 , pl. III, figs 8, 12, 13.

LECTOTYPE: TRH, A20-1264 ( Fig. 4 ), exclusively the small specimen in the box of the syntype of Heydrich no. 60, including thin section 6, is designated here as lectotype of Lithophyllum kaiseri (arrow on right in Fig. 4D ). The larger specimen and the thin section 1150 are here excluded from the type material of Lithophyllum kaiseri . Details of the nomenclatural history are reported by Woelkerling 1993: 132; Woelkerling et al. 2005: 170.

ETYMOLOGY: the specific epithet is dedicated to the collector, Dr. A. Kaiser ( Heydrich 1897b; Woelkerling 1993: 132; Woelkerling et al. 2005: 170).

ILLUSTRATIONS OF TYPE MATERIAL: Printz 1929: pl. 65, fig. 2.

TYPE LOCALITY: El Tor, Sinai Peninsula ( Egypt), from corals.

MATERIAL EXAMINED: Red Sea: Sinai Peninsula, El Tor, syntype of Lithophyllum kaiseri (Heydrich) Heydrich (leg. Kaiser: TRH, A 20-1264).

GEOGRAPHIC DISTRIBUTION: L. kaiseri is distributed in the Red Sea. The occurrence of L. kaiseri outside this area is unknown.

HABIT AND VEGETATIVE STRUCTURE: The lectotype of L. kaiseri (A20-1264, here designated as the small specimen only, in the box of the syntype of Heydrich; arrow in Fig. 4D ) is apparently a broken fragment of a larger plant, non-endophytic, with fruticose growth-form ( Fig. 4D on right). The protuberances have a smooth surface, are cylindrical or slightly compressed, branched, up to about 8 mm long and about 2–5 mm wide. The tapering protuberances are often fused together ( Fig. 4D on right). Plant structure pseudoparenchymatous ( Fig. 5A–B ). Basal or ventral layer (=hypothallium) dimerous, hypothallial cells 7–20 μm long and 10–15 μm in diameter. Peripheral region (= perithallium) composed of cell filaments curving outwards towards the thallus surface, L 5–30 μm long and 7–14 μm in diameter ( Fig. 5B–D ). Cells of adjacent filaments joined by secondary pit connections, cell fusions not observed ( Fig. 5C–D ). Palisade cells not observed. Single trichocytes 15–45 μm long and about 10–18 μm in diameter occurring in the perithallium and at the thallus surface ( Fig. 5C–E ). Single epithallial cells flattened, about 7–13 μm in diameter and 2–5 μm long ( Fig. 5E–F ; Tab. 2).

REPRODUCTION: Uniporate tetrasporangial conceptacles flush with the surrounding thallus surface, conceptacle chamber 270–350 μm in diameter and 85–125 μm high, with a pore-canal 55 μm long ( Fig 5G ; Tab. 2). Floor of the conceptacle chamber 11 cells below the thallus surface, including the terminal epithallial cell. Roof filaments 4–5 cells long, including the terminal epithallial cell ( Fig. 5G ). Gametangial and carposporangial conceptacles unknown.

REPRESENTATIVE SEQUENCE: KP696793 (LSU).

Figures

FIGURE 4. The syntype collection of Lithophyllum kaiseri Heydrich in TRH.A) Box A20-1264 in TRH. B) The carton box containing the syntype collection of L. kaiseri. C) Thin sections 6 and 1150, part of the collection A20-1264. Only slide 6 is here retained as part of the lectotype, because of the uncertain origin of slide 1150. D) The two specimens A20-1264 in TRH. The small plant (arrow) is here selected as lectotype of L. kaiseri. The larger specimen is excluded because of its uncertain origin.

FIGURE 5. Microscopical anatomy of the small plant (Fig. 4D, arrow) lectotype A20-1264 of L. kaiseri in TRH. A) Perithallial cell filaments (p) and an empty uniporate conceptacle, SEM stub 08112012b12. Note trichocytes are not apparent. B) Perithallus (p) in slide A20-1264_8 with abundant trichocytes. C) Detail of a thin portion of the thallus with hypothallus (h) and perithallus (p) of cells connected by primary and secondary pit-connections. D) Same as in B; detail of secondary pit-connections (arrow) and trichocytes (t). E) Epithallial cells in surface view with trichocyte trace (arrow), SEM stub 08112012b12. F) Same as in B; flattened epithallial cells (e). G) Detail of an empty uniporate conceptacle chamber with 4–5 cells forming the roof filaments.