Pyrenula montocensis
Pyrenula montocensis is a species of corticolous, crustose lichen in the family Pyrenulaceae. It forms a thick yellow to olive-green crust on tree bark, with many tiny surface pores and crystal-like bumps around its fruiting bodies. The fruiting bodies appear as small, rounded bumps that are partly embedded in the crust, and the species can be confirmed under the microscope by its exceptionally large ascospores divided by three internal walls. It was known only from a single collection made near San José in 1929, and the original description suggested it may have disappeared from the now-urban type locality. It has since been recorded in Colombia.
Taxonomy
It was described as a new species in 2008 by the lichenologist Robert Lücking, based on a specimen collected on 4 October 1929 from San Pedro de Montes de Oca, near San José in Costa Rica.Description
The lichen forms a thick, thallus with a that is yellow to olive green. The surface is marked by pseudocyphellae and by abundant crystalline e, which are often most conspicuous around the fruiting bodies. Its perithecia are solitary and hemispherical, ranging from immersed in the substrate to partly erupting, and measure about 0.5–1 mm across; the basal portion is covered by thallus tissue. The perithecial wall contains crystals and can be up to about 200 μm thick, while the apical ostiole is brown to black.Under the microscope, the has no oil droplets and turns orange when treated with iodine ; its filaments are unbranched. Each ascus contains eight gray-brown ascospores arranged in two uneven rows. The spores are 3-septate and fusiform with rounded ends, measuring about 75–90 × 25–30 μm. Their internal compartments are somewhat rounded and are separated from the outer wall by a thick internal layer. No lichen products were detected in the thallus.