Vermilacinia reticulata Spjut & Sérus., 2020

Spjut, Richard, Simon, Antoine, Guissard, Martin, Magain, Nicolas & Serusiaux, Emmanuel, 2020, The fruticose genera in the Ramalinaceae (Ascomycota, Lecanoromycetes): their diversity and evolutionary history, MycoKeys 73, pp. 1-68 : 1

Vermilacinia reticulata Spjut & Sérus. sp. nov. Fig. 13G, H

Diagnosis.

Recognized by its thallus divided into subcyclindrical-prismatic branches, appearing quadrangular in x-section, with sharply raised ± wavy ridges in a reticulate pattern, the primary branches shortly 5-lobed near apex.

Type.

Mexico - Baja California Sur, Vizcaíno Peninsula, 2.5 km SE of Punta Eugenia, rock outcrops along coastal hills trending west-east separated by wide arroyo, just east of the coastal community of La Lobera; 27°49.701'N, 115°03.454'W; alt. 35-40 m; 29.01.2016, R. Spjut & E. Sérusiaux 17153 leg.; on calcareous rocks of north facing slope; (LG! - holotype; BCMEX!; US!; hb Spjut at World Botanical Associates! - isotypes)[TLC: Salazinic acid, triterpene T3, zeorin, [-]-16α-hydroxykaurane, unknown triterpenes; DNA: MN811551 (LSU), MN811355 (ITS), MN757146 (RPB1), MN757332 (RPB2), MN757486 (GDP), MN757613 (EF-1α)]

Description.

Thallus divided into several or many subcylindrical-prismatic branches from a common basal attachment, up to 6 cm high and 5.5 cm broad. Primary branches ascending, once dichotomously divided near mid region, terminally shortly 5-lobed, with apothecia or, if without apothecia, obtusely rounded to bluntly pointed apex, compressed, 4-lobed or angled in x-section, occasional branches dilated and flattened to apex, sharply recessed along cortical ridges mostly in a reticulate pattern. Cortex pale yellow green or bluish green, smooth and deeply recessed within the ± reticulate or circular ridges along the face of the branch, 2-layered or a dense algal layer in outer medulla closely adhering as a third supportive layer, 75-150 μm thick. Medulla with a central dense grey area and outer white area. Apothecia on a short compressed lobe slightly constricted at junction with primary branch, bowl-shaped, to 2 mm diam. or up to 5 mm diam. with less concave disc or appearing to abort development, the branch terminally inflated and lobulate; thalline margin incurved, entire or crenulate with age, disc pale yellow green or yellowish with age or cream, concave; spores opaque, 1-septate, fusiform-curved, 8-10 μm. Pycnidia black, common to abundant on upper half of branches, immersed except ostiole flush with surface; conidia needle-like.

Chemistry.

Salazinic acid, triterpene T3, zeorin, [-]-16α-hydroxykaurane, unknown triterpenes UV + light blue without border, UV+ dark blue with border at Rf just above salazinic acid (TLC in solvent G).

Distribution and ecology.

Mexico, Baja California Sur, Vizcaíno Peninsula, known from a single location on conglomerate outcrops along north to northeast facing slopes near Punta Eugenia, occurring with Vermilacinia paleoderma .

Remarks.

Vermilacinia reticulata is distinguished from V. paleoderma by the sharply delineated cortical ridges and deeply recessed surface within, often appearing in a reticulate pattern. TLC revealed an unknown UV+ dark blue with a well-defined border under UV+ just above salazinic acid. Thalli with concentrated development of pycnidia on rugose cortical ridges resemble Niebla rugosa , which differs by the stepladder arrangement of the cortical ridges, in addition to the chemical and medulla character features that define the genus and species. Vermilacinia reticulata is sister to a clade comprising V. paleoderma and the newly described V. breviloba .

Etymology.

Epithet reticulata refers to the cortical ridges exhibiting a nice and obvious reticulate pattern.

Conservation Status.

The species may be threatened by off-road travel as discussed under V. lacunosa .

Additional specimens.

Same at the all type locality: R. Spjut & E. Sérusiaux 17175a [DNA: MN811502 (LSU), MN811306 (ITS), MN757420 (GDP), MN757557 (EF-1α)], 17179c [DNA: MN811504 (LSU), MN811308 (ITS), MN757101 (RPB1), MN757423 (GDP), MN757559 (EF-1α)], 17173D [DNA: MN811552 (LSU), MN811356 (ITS), MN757147 (RPB1), MN757487 (GDP, MN757614 (EF-1α)] (all: LG, hb Spjut at World Botanical Institutes).

Figures

Figure 13. New species of saxicolous Vermilacinia A, B V. breviloba (holotype) C, D V. lacunosa (holotype) E, F V. pustulata (holotype) G, H V. reticulata (holotype). Scale: 1 mm (A, C). Photographs by R. Spjut.