What is this plant that caused a rash?

I am taking a floriculture class, which is responsible for managing the FFA greenhouse. We found a plant that was interesting looking, and nobody knew what it was, so we disected it today. The leaves looked like corn leaves, but there were bulbs below the soil - like onions. They were light green, with layers that easily peeled apart. There were darker green growths coming from the bulb. It smelled kind of like a mix of cucumber and a bit of onion. The internal layers were coated with extremely slimy, clear liquid. Even though we wore latex gloves, the whole class soon saw a rash appear on their arms. It itched like crazy, so we took a field trip to the nurse’s office. About an hour later, the itch was gone, but evidence of a rash is still slighty visible. Any idea what this plant could be? We can’t narrow it down. And why would we all break out in itchy arm rashes? Weird, but thanks :)