I’ve only seen this on the back side of Arroyo Burro trail, blooming 14-26 June 2011 (hiked the same trail 22 May without noticing it). It was about 1.85 miles from Camino Cielo (or .75 miles from the bottom of the trail). N34.5233232,W119.7598937 On the far side of the trail from the creek.
On 26 June only the flowers on the top of the flowerspike were still blooming, the remainder were turning to seedpods.
Basal leaves had appeared by early March, 2012.
P. michaelii is on the list of rare and endangered plants maintained by CNPS.
This may be distinguished from P. elongata (also in our area) by the shape of the bottom petal (among other things). In P. m. the bottom petal, the lip, is rounded and broad, while in P. e. the lip is triangular and thinner.