Marin Navarretia species

Navarretia is a genus in the Gilia family (Polemoniaceae) that usually flowers late in spring here in Marin.
The species most familiar to us native plant folks is the common skunkweed, Navarretia squarrosa.
It needs no further introduction after we have made a first acquaintance of the significant downside of that pretty little blue wildflower.

The rare white-flowered vernal pool species, Navarretia leucocephala ssp. bakeri, Milo Baker’s navarretia, is the featured species this month. Found at only one site in the county, it can be abundant most years growing along the edges of Hidden Lake on Mt. Burdell.
The flowering season begins in May and lasts as long as the habitat doesn’t dry up completely.

Marin is not known for being prime vernal pool country, so this site is about as good as we get.
With the Navarretia are other locally unusual plants: the fern ally Howell’s quillwort (Isoetes howellii),
button-root celery (Eryngium aristulatum var. aristulatum), vernal-pool boisduvalia (Epilobium pygmaeum),
Howell’s foxtail grass (Alopecurus saccatus), hedge-hyssop (Gratiola ebractata),
and in early spring, floating mats of Lobb’s white water-buttercup (Ranunculus lobbii).

When Mt. Burdell became a public preserve,  three new-to-Marin  species of Navarretia  were found to add to the six species
mentioned in Howell’s Marin Flora of 1970.  Two are CNPS-listed rare species: the featured Navarretia leucocephala ssp. bakeri and
Navarretia cotulifolia, of which only 42 plants were counted this year.
The last of the three is the locally-common species Navarretia pubescens.

Text by Doreen Smith – Photos by Vernon Smith.  Click on the small images to see a larger versions.