After a month of keeping my eyes peeled, I finally found a patch of this little brown-striped lily. Fetid adder’s tongue (Scoliopus bigelovii) is easy to miss–it grows low to the ground, with flowers that blend in with the duff. But up close, it is spectacular! The three showy petal-like sepals are delicately striped with brown and white; they arch backward away from the three actual petals that rise upward like slim prongs. At the center of this confection is the three-pointed star of the pistil, and three purplish nubs of stamens which are nestled closely above each sepal.
I don’t actually think fetid adder’s tongue smells all that bad–but it certainly has a reputation for being stinky. Its fragrance is musty, like old mushrooms and forest floor. Which is exactly suited to the purpose of attracting the fungus gnats that are its pollinators. Each gnat rummages toward the smell, covering its head in pollen in the process. You can easily watch these little flies as they doze and flit among the flowers.
This plant is also sometimes called slink pod, because as the seeds develop the weight of the pod causes the stem to droop. Eventually it touches the ground, and often will root there–giving rise to a new plant.
The two leaves of fetid adder’s tongue also are distinctive–these pointed green ovals rise from the duff as the flower is blooming, often unfurling after it is past its peak. Once they emerge you can recognize them even without the flower present, since they are blotched all over with purple bruise-colored spots.
Scoliopus with pollen-decked fungus gnat
Thanks to Amelia and Doreen for giving me tips on where to find these!
Flowers Of Marin 
Damn!