Red Cage

Description

The red cage is easy to recognise: the mature fruiting body is a spherical, red or orange lattice with large meshes, usually 5–20 cm tall. It grows out of a whitish "egg", the remains of which stay at the base like a cup. The inside of the lattice is coated with an olive-brown, sticky slime that smells very unpleasant, like rotting meat.

It is a warmth-loving species originating from southern Europe, and in Poland it is rare and introduced. It grows on garden soil, lawns, in leaf litter and in flower beds covered with wood chips. The fruiting body appears quickly, in as little as a few hours, and collapses after about a day.

It resembles Clathrus archeri, which does not form a closed lattice, only several arms spreading out in a star shape. The red cage is inedible and there is no reason to collect it.

Identification features

Cap

No true cap. The young fruiting body is a whitish or greyish "egg" up to 6 cm in diameter, smooth at first, covered with a network of polygonal areas before it ruptures, with a gelatinous layer up to 3 mm thick. The mature receptacle is spherical or oval and hollow inside, made of spongy, interlaced arms forming meshes of unequal size (7–20 angular windows and 80–120 small mesh holes). Colour ranges from red to pale orange, lighter toward the base; it depends on temperature and humidity. The arms are up to 1.5 cm thick at the top, thinner toward the bottom, with a ribbed or wrinkled surface. Height 5–20 cm.

Hymenophore (underside of the cap)

No gills or tubes. Spores form in an olive-green to olive-brown, sticky, foul-smelling spore-bearing mass (gleba) that covers the inner surface of the lattice except near the base.

Stem

No stem; the lattice sits directly in the remnant of the egg envelope, which forms a cup-like volva at the base. The fruiting body is anchored to the substrate by cords of mycelium (rhizomorphs).

Flesh

The receptacle is spongy; a cross-section of an arm shows one wide inner tube and two irregular rows of outer tubes. The gleba has a very unpleasant smell resembling rotting meat, which attracts flies and other insects. The red and orange colours come mainly from carotenoids: lycopene and beta-carotene. Do not taste the flesh.

Spore print and spores

Spore print colour: no data. Spores elongated, oval-elliptical, smooth, 4–6 × 1.5–2.5 µm (descriptions give slightly different ranges). Basidia six-spored.

Habitat and distribution

Ecology. Saprotroph decomposing wood and plant debris. Grows singly or in groups in deciduous leaf litter, on garden soil, lawns, near woody debris, often in flower beds mulched with wood chips. Dispersed by insects attracted by the smell of the gleba.

Distribution. Considered native to southern and central Europe, Macaronesia, western Turkey, North Africa and western Asia; it has been introduced to every continent except Antarctica, often with imported garden mulch. Rare in Central Europe. In Poland it is rare and introduced; the first specimen was found in the 1980s at the Central Cemetery in Szczecin. In Ukraine it is protected and listed in the Red Data Book. In Poland it is not under species protection and is not on the list of fungi approved for sale.

Fruiting. No clear data for Poland; in North America from October to March. The receptacle develops from the egg in as little as a few hours and collapses after about a day.

What can it be confused with?

• Clathrus archeri — The fruiting body forms several (usually 4–8) tentacle-like red arms, which in a young specimen are joined at the tip and then spread out in a star shape; there is no closed lattice with meshes.
• Clathrus columnatus — The fruiting body consists of two to five long, vertical, orange or red columns joined at the top, rather than a lattice.
• Clathrus crispus — A tropical species; the meshes of the lattice have corrugated rims, which C. ruber lacks.

Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.

Interesting facts

• The species was already being illustrated in the 16th century; in 1560 Conrad Gesner mistook it for a marine organism.
• The German Mycological Society chose it as Mushroom of the Year 2011.
• In the former Yugoslavia and in rural France it was called the "witch's heart" (veštičije srce, cœur de sorcière).
• In 1980 Poczta Polska issued a stamp with the red cage, with a face value of 2 zł, in the series "Protected Inedible Mushrooms".