Could it have been the water-holding gel modules that one can buy to put in container plantings?

Yep, it sounds like the descriptions of water retaining crystals I've read . . .could someone have placed them in her garden bed last year? I've read that they can last for 5 years.

Google images 'dog vomit slime mold'.

Harmless to the garden, disgusting to human.

Thank you all for responding. I don't think it is the gel modules though. I was the only one that did any gardening for her last year and when I showed her this stuff she was as baffled as I was. What struck me as strange was the mounds were appr. 18" apart and there were 6 or 7 of them. This seemed to me like something that had formed by itself. These weren't in her regular gardens but out on the boulevard where she just has a bunch of daylilies planted. Oh well, just thought I'd try here to see if anyone had ever seen this stuff before. Thanks again, Kris

Yes - many of us have seen this stuff and we call it, as mentioned above, "dog vomit" fungus or mold.

It's not really a fungus but a slime mold. Calling it the "Dog Vomit Slime Mold" isn't very appealing so its scientific name is Fuligo septica. In other words, "sticky stuff".

Dog Vomit Fungus usually appears in late spring or summer following soaking rains. The slime mold is usually found growing in mulched areas near homes and office buildings, but can appear in the woods, too.

The color is bright yellow or sickly orange. The colorful growth occurs when the mold is beginning its fruiting stage. It can appear overnight causing people to question what it is and how it got there. The first instinct is to blame the dog across the street.

This wasn't dog vomit fungus. This stuff looked like a pile of ice. It was appr. 6" deep and 8" in diameter. It was gelatinous and slippery. It did have a tint of yellow but it definitely was not DV fungus.