Key Reasons to Go: The primary reason for this flower trip is to look for the rare Ring Mountain Calochortus.

Best Time to Go: May, or when the season turns dry. Even if you don't find the flower, there's nothing not to like about a nice hike on the hillsides of the Tiburon peninsula with its view out over San Pablo Bay as you enjoy your freedom to ascend the "mountain" and look for the flower that Steve's mom says is the "ugliest flower she has ever seen!"

UTM 10 545200 4195946 (NAD83)

Tripping to Tiburon

Ring Mountain sounds like a fantasy destination, but there on the east side of the Tiburon peninsula, just north of San Francisco and smack across the bay from San Quentin prison, surrounded by homes that cost more than the budgets of some small countries, you will find a small mountain of serpentine that in late May or early June is home to one of the strangest looking rare flowers of California: the Tiburon Mariposa, found nowhere else as a native plant!

The particularly interesting thing about this flower is that it went unnoticed (or at least not seen by anyone who knew it was unusual), despite being in a very populated area: it was basically hiding in plain sight, it was only recognized as something novel in 1971 by a local amateur botanist.

After it was found to be a new species, protection became a concern. The property, which had gone undeveloped even until 1971, needed to be protected and was purchased by the Nature Conservancy in 1995. It was turned into the protected native habitat now known as Ring Mountain Preserve and it is open to everyone without charge.

Today you can park on the edge of the road for free, then simply follow the marked trail up and over the hill. Early season visitors will find a nice green environment and a variety of wildflowers sprinkled about in the grasses and at the edges of the rocky outcrops, but it is better to go (again) when the weather heats up and the grasses turn golden. That is when you will find your way up and over the mountain, past the rocks marked as a petroglyph site, and then down along the last third of the trail; that is where you will start to find the well-camouflaged Tiburon mariposa, Calochortus tiburonensis.

Beauty is Relative

Actually, the Tiburon mariposa is pretty, it's just pretty in a different sort of way. While most other calochortus species are bright yellow, or orange, or even pure white, but decorated with purple and yellow nectaries and stripes; C. tiburonensis is sort of organic with its tan and pale green color scheme.

And look at those hairy petals! Man, that's some serious decoration.

It's a nice surprise that something like this is so easy for the casual observer to go and enjoy. The trail is not gated, the path is clearly marked, there are markers along the way to help you identify the common plants and shrubs, and then there you are: smack in the middle of a field with hundreds of rare plants for you to marvel at. And all the time you can look up and gaze out over that beautiful vista of the bay. Not a bad way to spend a day.

Geology and vegetation of Ring Mountain

Fish and Wildlife profile of Calochortus tiburonensis

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