Sparassis crispa  (cauliflower fungus)

Cauliflower fungus is widespread and fairly common in Britain, though apparently more scarce in Scotland and Ireland. It is found in much of Europe, but is rarer in some areas, and rated as Vulnerable in Belarus. It is also known from eastern North America, and reported from Asia and Australia, but these reports may represent a different species.

The fruitbodies of Sparassis crispa are cream to pale buff, often with yellowish tints when dry, and with white flesh. They arise from a rooting base, and are much branched, comprising compound lobes forming a dense cauliflower-like mass of up to 30 cm across and 25 cm high. The lobes are flattened or crisped, or sometimes more spoon-shaped, and rather brittle. The wavy lobes are mostly 1 - 2 cm wide, but occasionally wider, with rounded tips. The edges can be entire (smooth) or occasionally somewhat ragged or irregularly toothed. The lobes are fertile on the lower, or sometimes both surfaces. The basidia (spore-producing organs) are 45-60 x 6-7.5 μm, narrowly club-shaped, and 4-spored, with a basal clamp-connection. Slender sterile processes (hyphidia) are present amongst the basidia, are cylindric to rather wavy, or occasionally forked, and are 3 to 4 μm wide. The spores are colourless under the microscope, but pale yellowish in mass and are smooth, subglobose to broadly ellipsoid or ovate, and usually with a single guttule (oil-like drop inside the spore). They measure 5 – 7 x 4 – 5 μm. The flesh hyphae are interwoven, with thin or sometimes somewhat thickened walls, and are 3 – 8 μm in diameter. Inflated elements of up to 20 – 30 μm diameter and some refractive hyphae are present, and clamp connections are frequent throughout.

No specific threats are known, and the species is not considered of conservation concern in Britain. However, it is scarce in parts of Europe and is listed as Vulnerable in the Red Data Book of Belarus.

Cauliflower fungus is edible. The fruitbodies should be collected in good, fresh condition and thoroughly washed to remove dirt and grit from amongst the lobes.

The fruitbodies have been shown to have anti-tumour properties, and to contain chemicals which may stimulate the immune system and inhibit growth of the 'superbug' MRSA (methicillin-resistant Staphylococcus aureus).

As with many fleshy fungi, the fruitbodies are used for breeding by various insects, notably flies (Diptera) including some species of Leia and Mycomya (Mycetophilidae), Lycoriella (Sciaridae), and Spelobia (Sphaeroceridae), though none seems to be specific to Sparassis. The fruitbodies are sometimes eaten by rabbits.
 

Cauliflower fungus is commercially cultivated in Japan and China, and also in the United States, where the culture medium and methods are the subject of a US patent. However, it has reportedly also been grown on steam-treated coniferous sawdust.

Sparassis crispa can occasionally be found in the gardens at Kew, where it has been recorded in association with Cedrus, Pinus and Pseudotsuga species. It normally fruits in autumn (September to November).

Collections of Sparassis crispa and related species from throughout their range worldwide are preserved in the Kew Mycology Herbarium, one of the behind-the-scenes areas of Kew. These specimens are made available for study by bona fide researchers by appointment.

Checklist of the British and Irish Basidiomycota

Fungus Records Database of Britain and Ireland

Encyclopedia of Life

Medicinal Mushrooms

Mushroom Expert – Sparassis spathulata

MykoWeb

Red Book of Belarus - Sparassis crispa