How I wonder what you are…

Flanders Moss NNR

A few weeks ago, when monitoring out on one of the more remote sections of Flanders Moss, we came across a peculiar substance on one of the bog’s mossy hummocks. White, translucent and gelatinous, it is one of a number of substances known by the name ‘star jelly’ – and it is strange stuff indeed.

Star jelly has been recorded for centuries. In the eleventh century, the physician John of Gaddesden mentioned ‘stella terrae’, star of the earth, as a potential cure for abscesses – even then, the substance was associated with stars and meteors.

The 16^th century poet John Donne wrote in his poem Epithalamions X: ‘As he that sees a starre fall, runs apace,/ And finds a gellie in the place’; in the next century the poet Abraham Cowley wrote that ‘When they [stars] fall and meet th’ opposing ground/ What but a sordid slime is found?’  However, it wasn’t simply the fancy of poets, but the commonly held belief of many people that falling stars transformed into jelly when they hit the ground.

It remains unclear what led to this association, though the theory has been satisfactorily debunked – meteors are not scattering extraterrestrial goo across the countryside.

But what is it?

It seems likely that the term star jelly is used to describe a number of strange, gelatinous substances including slime moulds, which appear slimy during part of their life cycle, and Nostoc, a genus of cyanobacteria, which can swell into a jelly after rain.

However, the Flanders Moss star jelly appears to have been neither of the above. Instead, its colour and consistency point to it being the remains of unfertilised frog or toad spawn. This is indigestible by predators, who variously dismember their prey and leave the jelly behind, or swallow their prey and regurgitate the jelly. This expands on contact with water, explaining the large masses of jelly that are found. In autumn and winter, the eggs are tiny and not visible by the naked eye – but under an eyeglass, tiny black specks were visible in the star jelly.

In researching star jelly, I was somewhat surprised how little investigation has been conducted into the substance, or substances – and how many search results still pointed to it falling from the stars. Perhaps, after all, we’d rather like to believe it. It is a little more magical than frogspawn vomit, after all… but the truth is quite as interesting as the fiction.

A 2014 paper in the Glasgow Naturalist offers a fuller explanation of this phenomenon.