In south Mexico

Jul 20, 2007 18:16 GMT  ·  By

400 million years old mushrooms were known to grow as big as trees. But this one has been recently picked up, in a forest, close to a coffee plantation, in Mexico's southernmost state of Chiapas, Southern Border University Center officials said on Tuesday. The white mushroom was 20-kilo (41-lb) heavy and 70 cm (27 in) tall, belonging to the species Macrocybe titans, and could feed a family of four for over a day. This species usually grows a stem 5 in (13 cm) wide and 11 in (30 cm) tall while the cap can be 100 cm (40 in) in diameter. There are about 7 species of Macrocybe (family Tricholomataceae).

It was found near Tapachula, close to the Guatemalan border. "The mushroom belongs to a species that already had been found previously in Chiapas," said the custodian of the Micol?gica Collection of the Ecosul, Ren? Andrade.

This tropical mushroom grows in forests, from Chiapas and Florida to Brazil Puerto Rico, Martinique and Ecuador, but it is not known as an eatable species, and experimenting is not recommendable, as even if many related species in the Tricholomataceae are good to eat, some are poisonous. Better known species are Pleurotus (oyster mushrooms), honey fungi (Armillaria), the East Asian Tricholoma matsutake (matsutake), and the North American T. magnivelare (pine mushroom).

It is apparently saprobic (it eats death plant materials), growing alone or, more often, in clusters in grassy or sandy areas, or in ground disturbed by landscaping or, in Costa Rica, from leaf cutting ant (Atta) colonies. This is a little bit unusual, as most forest mushrooms form ectomycorrhizal symbioses with the trees' roots (the fungi deliver water and minerals to the tree and tree offers food made through photosynthesis). Most other Tricholomataceae are ectomycorrhizal fungi, forming symbiosis with various species of coniferous or broad-leaved trees.