Colonies on CYA almost do not grow: on the 7th day, 2-4 mm in diameter, sterile.
On the malt extract agar (MEA), colonies on the 7th day were about 1.5 cm in diameter, red, woolly, with white on the edge and red in the central part of the mycelium. Conidial sporulation is not always present, grayish to olive brown. The reverse is red-brown to dark brown, soluble pigment is not abundant, red.
On agar with yeast extract and sucrose (YES), colonies on the 7th day were 7-8 mm in diameter, sterile, whitish.
On the 7th day of oat agar (OA), the colony was about 2 cm in diameter, with red mycelium, usually without conidial sporulation. The reverse is dark cherry red.
Kleistotia sometimes form on the MEA at 30 ° C, yellow, almost spherical, soft, 20-60 microns. Askeys are 9-12 microns long, with 4-6 spores. Ascospores are ellipsoidal, prickly, 6.5-8 × 4.5-5.5 microns.
Conidiophores are occasionally present - single-tiered brushes or single phialides on a stalk 7–22 μm long and 2–2.5 μm thick, swollen at the apex to 4 μm. Phialides are flask-like and needle-shaped, 1-4 in a bundle, 4.5-16 × 2-3 microns. Conidia are almost spherical to ellipsoidal, with spiral ridges, 3-4 × 2-3 microns.
Differences from close species
A very limited growing species in most environments, produces a dark red pigment on MEA and OA. Forms yellow cleistothecia with prickly ellipsoidal ascospores. From Talaromyces ptychoconidium , which also forms conidia with spiral ridges, it differs in single-tier brushes and single phialids.
Soil mushroom described from France.
Talaromyces purpureus ( E. Müll. & Pacha-Aue ) Stolk & Samson , 2: 574 (1972). - Arachniotus purpureus E. Müll. & Pacha-Aue , Nova Hedwigia 15: 552 (1968).
Synonyms
- Arachniotus purpureus E. Müll. & Pacha-Aue, 1968
- Penicillium purpureum Stolk & Samson, 1972