Staheliomyces

Staheliomyces is a fungal genus in the stinkhorn family. The genus is monotypic, containing the single neotropical species Staheliomyces cinctus, also known as the strangled stinkhorn. It is found in Central America and northern South America. The fruit body of the fungus is a hollow, whitish, cylindric stalk up to 16 cm (6.3 in) tall, with conspicuous pits and holes. Near the top of the stalk is a pinched-off zone covered with unpleasant-smelling slimy spore mass called gleba. The gleba attracts insects like stingless bees that help disseminate the spores. The genus was first described scientifically by the German mycologist Eduard Fischer in 1921. The specific epithet honors Gerold Stahel who collected the type specimen in Suriname. The fungus has been called the 'strangled stinkhorn'. Like all stinkhorns, the fruit body begins its development as a partially submerged 'egg' form attached to rhizomorphs. The egg is roughly ovoid, measuring 1.5 to 2 cm (0.6 to 0.8 in) by 1.2–1.6 cm (0.5–0.6 in). The fruit body consists of a spongy, hollow white stalk between 12–16 cm (4.7–6.3 in) tall, with a collar of greenish-brown gleba positioned above the center, but below the apex. The glebal band is constricted compared to the width of the remainder of the stalk, between 1 and 2 cm (0.4 and 0.8 in) thick. The cap, or receptaculum, is at the top of the stalk; it is spongy, conical, and chambered, free from gleba. A volva sits at the base of the stem, and has rhizomorphs attached to it. The spores are elliptical, hyaline (translucent), and measure 2.5–3 by 1.2–1.5 μm. The edibility of the mushroom is unknown. Staheliomyces is a saprobic species, and typically found in soil rich with decomposing plant remains. It is found in Costa Rica to Ecuador, Panama, Peru, Guiana, and Bolivia, where it appears during rainy seasons. A field study from Ecuador reported that the fruit bodies of Staheliomyces are visited by species from the stingless bee genus Trigona. The bee visits are several minutes in duration, during which time small portions of the gleba are collected and stored in the pollen basket (corbiculae) of the hind legs. The authors determined that the corbiculae of approaching bees are always empty. Bee corbiculae are normally used to carry food and nest-building material, and the gleba of Staheliomyces may be used for one of these purposes, but the authors did not observe the bees after they had collected the gleba.