Allographa upduna
Allographa upduna is a species of bark-dwelling script lichen in the family Graphidaceae. It forms a smooth, greenish-grey to grey crust and produces isidia, small coral-like outgrowths used for asexual reproduction. The fruiting bodies are elongated and slit-like, typical of script lichens. The species grows in the semi-evergreen forests of Arunachal Pradesh in northeastern India.
Taxonomy
Allographa upduna was originally described as Hemithecium isidiatum by Dalip Kumar Upreti and Urvashi Dubey in a 2011 paper co-authored with Sanjeeva Nayaka. The holotype was collected on bark in Kago-kashi forest near Kabu village on 20 March 2006 and is housed in the herbarium of the National [Botanical Research Institute] in Lucknow. In the original publication, the species was classified in Hemithecium, which contained 44 species worldwide at that time. Described as the first known member of Hemithecium, it was also characterized by its hyaline, ascospores and the presence of salazinic acid. The epithet isidiatum refers to the isidia on the thallus.Robert Lücking and Klaus Kalb later introduced the replacement name Allographa upduna for Hemithecium isidiatum. The original epithet could not be used in Allographa because it would conflict with the already-published name Allographa isidiata. The name upduna is formed from the initials of the authors of the original description.
Description
Allographa upduna is a crustose lichen that forms a smooth, thick crust that is greenish grey to grey, sometimes becoming greyish-brown to pale brown. The thallus produces isidia that are simple to -branched, about 0.2–0.4 mm in diameter and 0.3–1.0 mm tall, and the same colour as the thallus and readily detached.The fruiting bodies are that are greyish white to grey, prominent and emergent, mostly, and typically 1–4 mm long and 0.25–0.5 mm wide. Their rim is non- and colourless to pale yellowish-brown; it has a narrow basal region and a broader upper region marked by several grooves. The are convergent and entire, irregular on the outer side, and covered by a thalline veil up to the top; crystals also occur above the exciple. The is dark brown and 6–9 μm high, while the hymenium is hyaline, not, and 80–120 μm high; beneath it is a pale yellow to yellow about 14–18 μm high. The asci contain 4–8 spores and measure about 45–77 μm long and 13–20 μm wide. The ascospores are hyaline, oblong-ellipsoid and, with 6–17 transverse septa and 1–5 longitudinal septa, measuring 14–27 × 6–8 μm, and they show an iodine staining reaction described as I+ blue. Thin-layer chromatography detected salazinic acid in the thallus.