Iris macrosiphon, Soda Canyon Road, Napa County, California
Range: Widespread in central California's coastal ranges and facing Sierra Nevada foothills; south to Mariposa and Santa Cruz counties, replaced by I. tenuissima north of the Great Central Valley. Near sea level to around 3,000 feet elevation.
Original material: Corte Madera, Marin County, California 1854
Key identifying features:
1. Long floral tube; 1½ to 4½ inches
2. Tube top bowl-shaped; petals separate near bowl's rim
3. Spathes narrow, enclose ovary and most of tube
4. Individual stems or small clumps
Flower color: Wide color spectrum: usually lavender or lilac-purple with a white signal spot, but sometimes cream, yellow or white; local populations tend to show variations of a single color pattern.
Habitat: Sunny, open woodland sites, grasslands or meadows with filtered or no shade. Replaced by other species in adjacent shaded woodland habitats.
Comments: "Ground iris" is another common name; plants growing in full sun often have very short stems (photo on right). Clumps form when seeds from several generations fall in the same area.
Iris macrosiphon is a widely distributed species made up of many distinctive regional populations, each with its own long and separate history. It
comes into contact with nearly all the other California PCIs, and over millenia, most have contributed to the genetic makeup of today's populations.
In past decades some populations were given their own names. But with so much variation, and features that grade into each other, no one has yet been able to separate unique, consistent subgroups.
The record is further confused by book and magazine articles using the name macrosiphon ("large" + "tube") for misidentified plants of other long-tube species, especially I. fernaldii and I. tenuissima. And sometimes true macrosiphon is found labled with some other name, like "Iris hartwegii". In I. macrosiphon, the ovary is almost always well hidden inside the two spathes, and the petals and sepals divide close along the rim of a bowl-like swelling at the top of the floral tube.