British distribution: Widespread but uncommon. (UKBAP species, "Low Risk")
Identification and variation
Old specimens can lose much of their colour and become yellowish and then need more care in their separation from similarly old and faded fruitbodies of the H. persistens complex. It should also be noted that H. psittacina may rarely be pink - such an individual, but showing green at the top of the stem, is illustrated on the H. psittacina page. The very viscid H. laeta can be pinkish brown.
Although not common, H. calyptriformis is illustrated in many of the popular identification guides.
It shows little variation, though a white form is known, f. nivea (which might easily be confused with white, conical species of Tricholoma). See the scan of Cooke's classic illustration, reproduced below.
A variant with a coloured stem, larger spores and seemingly differing cap cuticle (lacking a "true ixocutis") has been distinguished as var. domingensis, based on a single collection from the Dominican Republic, but with another collection from the USA and one from southern England (Cantrell & Lodge, 2000). Since the cap cuticle of the English collection was said to match that of normal European var. calyptriformis and since colour in the stem is a variable character, it would seem that more knowledge is needed on spore size variation in this species before it can be clear whether var. domingensis deserves its current acceptance as British, or indeed is generally worthy of taxonomic recognition.
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