Trichoglossum hirsutum is a species of fungus in the familyGeoglossaceae. In the UK, it has been given the recommended English name of hairy earthtongue.[1] In North America it is known variously as velvety black earth tongue,[2]velvety earth tongue, shaggy earth tongue, or black earth tongue. DNA evidence suggests the hairy earthtongue may be a species complex.
Ascocarps are club-shaped, up to 9 centimetres (3+1⁄2 in) tall, black to dark brown, with a swollen, spore-bearing head, up to a quarter or half the ascocarp height, and a finely hirsute, cylindrical stipe (stem) up to 5 millimetres (1⁄4 in) wide.[4] Microscopically, dark, thick-walled, acute setae are present. The asci are 8-spored, the ascospores 110–160 × 5–7 μm, becoming 15-septate at maturity.[3]
The epithethirsutum (Latin: 'hairy') refers to the fine hairs (setae) that cover the ascocarp.[5]
Similar species
Many Trichoglossum species appear similar in the field and can only be identified by microscopic examination.[4] Superficially similar species of Geoglossum lack setae and are not finely hirsute under a hand lens.[4]Thuemenidium atropurpureum is usually more robust and can be slightly purplish.[4]Microglossum species have non-black hues.[4]Tolypocladium ophioglossoides can appear similar in age.[4]
Conservation
In Europe the short-spored earthtongue is typical of waxcap grasslands, a declining habitat due to changing agricultural practices.
^Arora, David (1979). Mushrooms demystified: a comprehensive guide to the fleshy fungi of the central California coast. Berkeley, Calif: Ten Speed Press. ISBN978-0-89815-010-0.