YOSEMITE, Calif. (KSEE/KGPE) – If you see a spaghetti-looking substance on a rock while hiking in Yosemite, park rangers ask that you do not eat it.

Triggered by warm weather in the spring, park officials say what might look like spaghetti on a rock is, in fact, California dodder – an obligate parasite that relies on native plants for nutrients and water.

Park officials say dodder sprouts from seeds, producing lots of very small vines that wrap around another plant’s stem to feed off of it. Not just any host will do – California dodder scouts out plants that are mature and healthy enough for it to live off.

According to the National Park Service, dodder blooms and flourishes throughout the summer. When the colder temperatures and winter months come, that’s when park officials say it dies, leaving behind seeds that remain viable until the following spring.

So is there any risk to humans? Park officials say no.

Like any good parasite, park officials say dodder seldom kills its host and plays a key role in lots of ecosystems by limiting the size of dominant species and reducing the amount of competition between plants for the limited plant food available.