Malmidea subcinerea is a
crustose lichen characterised by a continuous
thallus that ranges from 80 to 120
μm in thickness. The thallus surface is smooth and dull, with colours from grey and greenish grey to olive, and neither
isidia nor
soralia present. The
medulla of the thallus is white and does not react to a solution of
potassium hydroxide (K−). This species' is , consisting of
green algal cells measuring 10–12 μm in diameter. The apothecia of
Malmidea subcinerea are
sessile and rounded, measuring between 0.4 and 0.9 mm in diameter and 0.2–0.3 mm in height. Initially, the apothecial are flat but become slightly convex, coloured light beige to light greyish brown. The margins around the discs are approximately 0.15 mm thick, slightly prominent, and vary from whitish grey to brownish grey in colour. The is of the
piperis-type, more or less
hyaline (translucent) at the periphery and brownish at the centre and upper periphery. This species lacks
hydrophobic granules. The is about 10 μm high, hyaline or slightly brownish, while the is centrally 50–70 (up to 125) μm high, dark brown to reddish brown, and does not react to potassium hydroxide (K−). The , if present, is light brown, and the
hymenium is hyaline, measuring 100–120 μm in height. The
asci within
Malmidea subcinerea are 60–75 by 10–15 μm in size, each containing 6–8 . These spores are broadly
ellipsoid to , lack
septate (internal partitions), with a uniformly thickened wall and a approximately 1 μm thick. The spore sizes range from 9–12 by 5–7 μm. Chemically, no
lichen substances were detected in
Malmidea subcinerea through
thin-layer chromatography analysis. ==References==