What is so special about the ferns on Palomar Mountain?

Dear Matt:

After 30 years as a San Diego resident, I finally visited the telescope on Palomar Mountain (man, that thing is HUGE). Anyway, as you enter the observatory grounds, there are all these signs that say "NO PICKING OF FERNS" translated into a couple of Asian languages. What's so special about these ferns? Are they some sort of Asian folk remedy?

-- Curious but Fernless in SD

Yum! Fern soup. Fern salad. Cream-chipped fern on toast. The curly baby fiddleheads that grow each spring from Palomar's bracken ferns are considered quite a delicacy. Particularly in Asia. But you can be overcharged for them in restaurants right here in the USA too. Picking anything, ferns or otherwise, on state land (Palomar) is verboten; but you can get a permit to pick fern sprouts on some federal land. Ferns may look all green and woodsy and earthy and healthy, but here's a tip. If you're going to eat them, cook them for at least ten minutes. Raw or undercooked ferns can cause, er, unpleasant digestive reactions -- all-day barfathons, 'notherwords. One type of fern apparently loves sucking up arsenic. As a result, scientists now are studying the feasibility of planting ferns on toxic waste sites to extract ugly substances from the soil.