Malmidea hechicerae
{{Short description|Species of lichen}}
{{Use British English|date=December 2023}}
{{Use dmy dates|date=December 2023}}
{{Speciesbox
| image =
| image_caption =
| taxon = Malmidea hechicerae
| authority = Kalb (2021)
| range_map = {{Infobox mapframe|coord={{coord|8|40|N|71|10|W}}|zoom=5}}
| range_map_caption = Holotype site: Monte Zerpa, Venezuela
}}
Malmidea hechicerae is a species of corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It is found in Venezuela.
Taxonomy
The lichen was formally described as a new species in 2021 by the German lichenologist Klaus Kalb. The type specimen was collected from Monte Zerpa (Distr. Libertador, Mérida) at an elevation of {{convert|2200|m|ft|abbr=on}}, where it was found growing in a cloud forest. The species epithet refers to its type locality, known as La Hechicera.
Description
Malmidea hechicerae is a crustose lichen with a continuous thallus that is 40–60 μm thick. The thallus surface is {{lichengloss|verrucose}}, with the {{lichengloss|verrucae}} being more or less spherical and measuring 0.1–0.25 mm in diameter. These verrucae have a dull, whitish-grey appearance. The species lacks both soralia and isidia (reproductive propagules). The medulla of the verrucae and thallus is white, reacting K+ (lemon-yellow), occasionally showing a slightly orange-yellow hue, and P+ (orange), best observed in sections under a light microscope.
The {{lichengloss|photobiont}} of Malmidea hechicerae is {{lichengloss|chlorococcoid}} with cells measuring 6–8 μm in diameter. The apothecia are sessile and rounded, ranging from 0.6–1.3 mm in diameter and 0.3–0.4 mm in height. The {{lichengloss|discs}} of the apothecia are more or less flat and vary in colour from beige to brownish or dark brown. The {{lichengloss|excipulum}} is of the granifera-type, remaining {{lichengloss|entire}}, and is whitish to cream-coloured, bulging, and elevated above the disc. The {{lichengloss|ectal excipulum}} is hyaline (translucent) to brownish, particularly at the edges, while the medullary excipulum is filled with colourless opaque {{lichengloss|granules}} that partly dissolve in potassium hydroxide, producing a greenish-yellow efflux.
The {{lichengloss|subhymenium}} of the lichen is roughly 20 μm high and light brown, with a centrally located {{lichengloss|hypothecium}} measuring 50–70 μm high that narrows towards the margin and is dark brown, not reacting to K. The {{lichengloss|epihymenium}} is light brown, and the hymenium is hyaline, measuring 70–80 μm in height. The asci are 55–65 μm long and 8–15 μm wide, each containing 6 to 8 {{lichengloss|ascospores}} that lack septa. These ascospores are broadly ellipsoid, with equally thickened and {{lichengloss|halonate}} walls, measuring 13–17 by 7–9 μm, and are surrounded by a {{lichengloss|halo}} of 1–1.5 μm.
In terms of chemistry, Malmidea hechicerae is characterized by several xantholepinone substances, detectable using thin-layer chromatography. Atranorin is not detected in this species. Malmidea coralliformis similar in appearance to M. hechicerae but has a different set of xantholepinones.
References
{{Reflist|refs=
{{Catalogue of Life |id=B353R |title=Malmidea hechicerae Kalb |access-date=22 December 2023}}
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