| Microstoma floccosum | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Pezizomycetes |
| Order: | Pezizales |
| Family: | Sarcoscyphaceae |
| Genus: | Microstoma |
| Species: | M. floccosum |
| Binomial name | |
| Microstoma floccosum | |
| Synonyms | |
Microstoma floccosum is a species in the cup fungus familySarcoscyphaceae. It is recognizable by its deep funnel-shaped, scarlet-coloredfruit bodies bearing white hairs on the exterior. Found in the United States and Asia, it grows on partially buried sticks and twigs ofoak trees.
One variant species has been described,M. floccosum var.floccosum, found in China and Japan, with large spores.[1] The fungus originally described asMicrostoma floccosum var.macrosporum was recognized as an independent species in 2000 and renamed toM. macrosporum. It differs fromM. floccosum by fruiting season, asci and ascospore size, and theultrastructure of the hairs.[2]
The diameter of the cup- or funnel-shaped fruit bodies is 0.5 to 0.8 centimetres (1⁄4 to3⁄8 in) in diameter; the margins of the cup are curved inwards when young.[3] Both the interior and exterior surfaces of the cup are scarlet red. The exterior surface is covered with stiff white hairs. Details of the hair structure may be seen with amagnifying glass: they are up to 1 mm long or more, translucent, thick-walled, rigid and more or less sword-shaped with simple, sharply diminishing bases. They are connected to the fruit body at the junction of internal tissue layers called the medullary and ectal excipulums. When the hairs come in contact with an alkali solution of 2% potassium hydroxide, the thick walls of the base of the hair first swell in size and then dissolve, releasing the contents of the internal lumen.[4] Thestipe is cylindrical, and about1 to 5 cm (3⁄8 to 2 in) long by 1–2 mm thick.
The species is inedible.[5]
Thespores are 20–30 by 14–16 μm; theasci (spore-bearing cells) are 300–350 by 18–20 μm.[6] Theparaphyses (sterile, upright, basally attached filaments in thehymenium, growing between asci) are thin, slightly thickened at the tip and contain many red granules.[3]
Microstoma apiculosporum is a species fromTaiwan that has spores with short, sharply pointed tips.[7]Scutellinia scutellata has a shallow red cup, no stalk, and black hairs on only the edge of the cap margin. The stalked scarlet cup,Sarcoscypha occidentalis, has a shape, size and color that somewhat resembleM. floccosum, but it lacks any surface hairs, and the cup is not as deep.[8]
Microstoma floccosum has been collected from the United States,[3] India,[4] China,[1] and Japan.[2]
Asaprobic species,M. floccosum grows scattered to clustered together, attached to wood that is typically partially buried in the earth. A preference for bothoak andShagbark hickory has been noted.[3]