Ring Mountain

Ring Mountain is located at the northern end of the Tiburon Peninsula in south central Marin County. This 602 feet high mountain has distinctive mineralogy, flora, fauna, and Indian petroglyphs. Rocks on the mountain are part of the Franciscan Complex and are associated with many different minerals. The Mountain is capped by large sheets of serpentine that range from 10 to 50 feet thick and are probably more than 150 million years old. The Nature Conservancy acquired title to 377 acres in 1985 and has created a wildlife preserve which is open daily year round. Collecting of rocks or plants is prohibited. There is a 1 1/2 mile moderately steep trail loop. Spring wildflowers are at their best from April through June. Three notable plant species occur naturally only on the harsh serpentine soils of the Tiburon Peninsula: Castilleja neglecta, Streptanthus niger and Calochortus tiburonensis.

Ring Mountain Click for map


Allium lacunosum var. lacunosum was photographed by Nhu Nguyen. This taxa occurs on serpentine outcrops by the thousands. The petals fade to a rusty brown and are persistent as the seeds mature.

Allium lacunosum var. lacunosum, Nhu NguyenAllium lacunosum var. lacunosum, Nhu NguyenAllium lacunosum var. lacunosum, Nhu NguyenAllium lacunosum var. lacunosum, Nhu NguyenAllium lacunosum var. lacunosum, Nhu NguyenAllium lacunosum var. lacunosum, Nhu Nguyen

Brodiaea elegans photos taken by Nhu Nguyen.

Brodiaea elegans, Ring Mountain, Nhu NguyenBrodiaea elegans, Ring Mountain, Nhu Nguyen

Calochortus luteus was photographed on a site on the Tiburon peninsula, at the base of Ring Mountain. Photo by Mary Gerritsen

Calochortus luteus, Mary Gerritsen

Calochortus tiburonensis is a very "secretive" plant. You can be looking right at it, and not even see it! The colors are well camouflaged against the back drop of dried grasses, and greenish-brown rocks. The photos below are by Mary Gerritsen

Calochortus tiburonensis, Mary GerritsenCalochortus tiburonensis, Mary GerritsenCalochortus tiburonensis, Mary Gerritsen

Chlorogalum pomeridianum photos were taken by Nhu Nguyen. Photos 1-4 taken June 2010 are of various aspects of the flowers. Photo 5 shows the glaucous blue leaves.

Chlorogalum pomeridianum, Nhu NguyenChlorogalum pomeridianum, Nhu NguyenChlorogalum pomeridianum, Nhu NguyenChlorogalum pomeridianum, Nhu NguyenChlorogalum pomeridianum, Nhu Nguyen

Delphinium hesperium subsp. hesperium was photographed by Nhu Nguyen.

Delphinium hesperium ssp. hesperium, Nhu NguyenDelphinium hesperium ssp. hesperium, Nhu NguyenDelphinium hesperium ssp. hesperium, Nhu Nguyen

Triteleia laxa photographed by Nhu Nguyen.

Triteleia laxa, Ring Mountain form, Nhu Nguyen

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Page last modified on February 15, 2014, at 05:22 PM