The first of our wild iris are beginning to bloom, despite our recent soggy weather.
Last year we only casually observed this iris blooming on some of the slopes around the property, and knew that we had a yellowish-white species here.
However, it was late in the season and difficult to note much in the way of identifying features as the flowers were fading. We assumed this may have been a variety Iris douglasiana, or Iris macrosiphon. It turns out we were wrong on both counts.
Close inspection of the flowers blooming this spring have revealed our iris to be Iris fernaldii. This is a native species, with a limited range. Iris fernaldii is endemic to the coast ranges of northern and central California, from Mendocino and Tehama counties, south to Santa Cruz and Santa Clara. This species is typically found in mixed evergreen forest, and for much of the year could be easily overlooked as a nondescript, broad leafed, grassy clump.
This iris was more challenging to identify than we expected, as it is very similar in appearance to the pale form of Iris macrosiphon. However, I. fernaldii lacks the bowl-shaped enlargement at the top of the corolla tube that is seen in I. macrosiphon. The corolla tube of Iris fernaldii is more funnel shaped, and more elongated. More of a flare, than a bowl.
Fernald’s iris crosses readily with other native irises that may be found nearby, including Iris douglasiana, Iris innominata, and Iris macrosiphon, which can further confound identification. Thus far this is the only iris we’ve observed on the property, and where it likes to grow, it appears to be quite prolific! The ability of Iris fernaldii to hybridize in the wild, occasionally results in some plants of this species being reported as having lavender flowers. We have only observed the yellowish-white form here on the property.
The flowers of Iris fernaldii appear between April and July, and are comprised of three standards, three falls, and three style arms, under which the stigma and anthers are found.
Iris fernaldii has flowers that are a cream to yellow color, but with a pronounced burgundy-purple veining, with darker yellow prominent veins and a yellow signal. Note that this is a beardless species of iris. Beardless iris usually have a signal (an area of bright contrasting color) that replaces the beard seen in bearded iris.
The petals (or standards) of Iris fernaldii are upright and slightly spreading, shorter and narrower than the sepals (falls), and similar in coloration. The flowering stalk is shorter than the surrounding leaves.
The leaves of this iris species are typically a dark gray-green. Some report that the base of the leaves are burgundy red in I. fernaldii, and white for I. macrosiphon, but much variability in coloration has also been observed (perhaps a result of hybridization between species at some point in time). The leaves emerge from fibrous branching rhizomes as dense, compact clumps.
The seeds produced by native iris are attractive to wildlife, and the flowers provide nectar to insects and hummingbirds.
Numerous Native American tribes, including the Pomo, Karok, and Tolowa are known to have made very fine cordage from wild iris leaves, which in turn was crafted into fishing nets, string, rope, and snares strong enough to catch deer. 
The Society for Pacific Coast Native Iris suggests that this particular species favors the unique soil and climate conditions of central California’s wine growing region. The soils that favor Fernald’s iris, apparently also favor good vineyard crops…which hopefully will be good news for us when we get around to planting a few grapes.
Iris fernaldii spreads via underground rhizomes, although its fibrous roots are difficult to dig, and from seed. It prefers a slightly acidic to neutral soil, will grow in part sun to shade, and tolerates drought quite well. Iris fernaldii is occasionally available through some specialty California native plant nurseries.
In cultivation this species needs good drainage, and reportedly benefits from some summer watering and a light mulch. Here the majority of plants have a southeast to southern exposure, with no supplemental irrigation, and seem quite drought tolerant in our soils. Although the leaves do scorch if exposed to prolonged full sun. We’ll be curious to see if the iris along the edge of the orchard perform better with exposure to occasional supplemental irrigation in the years to come.
 Daniel E. Moerman’s Native American Ethnobotanical Database