I honestly don't know, Alice. I never looked into that, either here in NJ or at our place in Pennsy.
So far, all the places were we see "plants of value" seem fairly save. Today's posted stand is pretty invisible to most people, you really have to know what you are looking for. And it is not in any danger of being bulldozed, the slope is way to steep and houses are much set back.
We similarly discovered a gigantic stand of Spiranthes cernua on Rt 380 in PA some years ago. In a good year one might see more than a thousand blooming Orchids on a slope right next to the highway. Luckily it is too steep to be mowed!! I would be afraid giving out the exact location, fearing that people might start digging.
To the stands of Cyp acaule and other Orchids at our Pennsy place - they are so well hidden, it took US some years to find exact locations. Comparing it to needles in haystacks is about right. Sometimes we protect rarer emerging plants with a cage, so the Deer don't nibble them away.
