Lightfootiella montana (Lightfoot) Hašler, Pentecost, Jahodářová, Dvořák et Poulíčková 2018

Hašler, Petr, Pentecost, Allan, Jahodářová, Eva, Dvořák, Petr & Poulíčková, Aloisie, 2018, Taxonomic revision of Ulva montana (Lightfoot 1777) and description of a new genus of Lightfootiella (Cyanophyceae, Chroococcaceae), Phytotaxa 362 (2), pp. 173-186 : 177-180

Lightfootiella montana (Lightfoot) Hašler, Pentecost, Jahodářová, Dvořák et Poulíčková comb. nov. ( Figs 1–4 )

Basionym: Ulva montana Lightfoot (1777: 973)

≡ Palmella alpicola Lyngbye (1819: 206 , tab. 69B), Palmella montana Agardh (1824: 15) ,? Gloeocapsa shuttlerworthiana Kützing (1843: 173) , Sorospora montana Hassall (1845: 309)

– Protococcus magma Brébisson in Brébisson & Godey (1835: 40), Gloeocapsa magma (Brébisson) Kützing (1843: 173) , Chroococcus simmeri Schmidle ex Geitler (1932: 198) , Gloeocapsa magma var. simmeri (Schmidle) Nováček ex Geitler (1932: 1164)

Thallus macroscopic forming thick mucilaginous dark red to brownish layer. Colonies microscopic, spherical, hemispherical or irregularly lobate, usually 25–50 μm in diameter. Colony disintegrates into a few two- or four-celled sub-colonies after envelope gelatinization. Mucilage envelopes are wide and consist of internal distinct conspicuously red-orange or rusty layers containing granules (probably pigments) and external amorphous and hyaline mucilage. Cells spherical, hemispherical, oval, 7.45–11.84 × 5.62–10.02μm, blue-green to grey-green with conspicuously granulated cytoplasm and wide cell wall 0.5–0.8 μm in thickness. Cells grow up to original shape and size after colony disintegration. Reproduction by binary fission in three planes. Resting and reproductive cells not observed.

Habitat: aerophytic to subaerophytic, on quartzite or granitic stones, sometimes among mosses, in mountains.

Occurrence: Scotland (Isle of Skye, Ben Eighe, west coast of Scotland), Wales, Faroe Islands, probably in Scandinavia.

Figures

FIGURE 1. Desiccated type material of Lightfootiella montana, status familiaris lamellosus, collected by Lightfoot 1777 at Isle of Skye. A. sample under magnification of 400×. B–D. Sample under magnification of 1000×. * diffluent mucilage, + sparsely stratified mucilage envelopes with red-orange granules, ++ densely stratified mucilage envelopes with red-orange granules. Scale bars: 10 μm.

FIGURE 2. Lightfootiella montana, status familiaris lamellosus and status perdurans, fresh material originating from Ben Eighe, collected by Pentecost 2016.A–C. Formation of young colonies. D. Disintegration and gelatinization of the mucilaginous surface layers. E. released and divided cell without mucilaginous envelopes. F. Disintegrated colony.G. Rupture of outer mucilage layers. H.Aggregation of colonies into flattened thick layer. I. Formation of diffluent mucilage. J. Colony disintegration. K. Disintegration of large colony.A, B,D–K. Status familiaris lamellosus. C. Status perdurans. * diffluent mucilage, + sparsely stratified mucilage envelopes with red-orange granules, ++ densely stratified mucilage envelopes with red-orange granules. Scale bar: 10 μm.

FIGURE 3. Life cycle and reproduction of Lightfootiella montana. A. Growth and disintegration of small colonies. B. Gelatinization and disintegration of colonies within population. C. Formation of population consisting of individual sub-colonies covered by layered and diffluent mucilage envelopes. Scale bar: 10 μm.

FIGURE 4. Line drawings of Lightfootiella montana holotype and putative or similar specimens published in 19th and beginning of 20th century. A. Ulva montana (Lightfoot 1777). B. Palmella alpicola (Lyngbye 1819). C. Sorospora montana (Hassall 1845). D. Palmella alpicola (Wille 1918). E. Protococcus magma Brébisson 1835. F. Gloeocapsa shuttlerworthiana (Kützing 1843). G. Gloeocapsa shuttlerworthiana (Getler 1932).