Oregon Irises Inspire

Oregon irises
Two terrific Oregon irises, Iris “innominata” (left) and I. tenuifolia ssp. purdyformis.

Adventure and exploration is the reason I went into the field of plant taxonomy and ecology. I wanted to discover the wonders of this world and I wanted to understand how they were connected to all facets of their environment. Our recent trip to the Siskiyou Mountains in southwestern Oregon and California, with our companions and guides Sean Hogan and Preston Pew, provided an opportunity of a lifetime. Since childhood I have dreamed of walking through these hills among the Iris, Camas, Mariposa Lilies and Fritillaries that are only found in this small corner of the world. Sean and Preston’s lifetime of exploration of the area was generously shared and allowed us to observe plants that we never could have seen on our own.

Seed collection is difficult this time of year, but is the preferred method of propagation for most plant species we would like to exhibit in our Rock Garden and Traveler’s Garden. The purpose of trips during flowering rather than fruiting season is to find the best clones and know which to return to for gathering seed. Perhaps more important, we are allowed to see the habitats that we will be installing at Heronswood and thus better understand their structure. Observations and photographs of the characteristic rocks, soil, water, exposure, and inter-relationships of all members of the community are essential to the installation of a true natural community garden.

Fritillaria gentneri
Fritillaria gentneri
What did we see? Way too much to include here, so I will attempt to hit some highlights. Within two hours of arriving at the airport in Medford we were surrounded by what may be the most glorious of our native fritillaries. This tall and handsome plant bears lily-sized flowers of scarlet spotted with yellow. The location was not some far-flung wilderness but rather an old section of graveyard, where native ground cover still exists. It was a surreal experience watching these elegant blooms flutter above a carpet of Henderson’s Shooting Stars and Giant Hounds Tongue, all adjacent to tombstones! Unfortunately, the habitat for this endangered plant has been badly degraded throughout its tiny range.

Most of us are familiar with Pacific Coast Iris hybrids. These plants come in an amazing array of colors and are derived from a large suite of species that freely hybridize in the garden. They make great garden plants in our area, being tolerant of drought, tough as nails, and beautiful. Their attributes make them ideal candidates for planting in a world where climate and water availability are changing. The wild species, from known locations, are not commonly seen in botanical gardens, but are abundant in the Siskiyous, and every plant seems to have a different and alluring color.

In the open, rock-strewn serpentine barrens, we found narrow-leaved Iris chrysophylla. Most plants of this species have flowers in various shades of cream with darker radiating lines along the falls (the lower 3 tepals). Higher up the slopes and along the course of the Illinois River, both on and off serpentine, we encountered a superb Iris with golden flowers (above) that is similar to, but not exactly the same as the golden Iris innominata. These medium-sized plants were among the most thrilling of the trip as they exhibit variation in color from creamy-yellow to brilliant gold. They may be an undescribed species or represent a stable hybrid that has overtaken the area. The true I. innominata is seen along the Rogue River and though we didn’t find them in flower, Sean Hogan found some glorious colonies after we parted company. Another Iris with neon purplish-blue flowers that appears to be Iris thompsonii, was good to see in the wild as we have it now flowering at Heronswood from earlier trips. A tall and stately plant known as Iris tenuissima ssp. purdyformis was located by Ross and I on our last day. The best form displayed a bicolored flower of bluish falls and lighter standards (the upper 3 petals).

All together, I made notes on over 300 species during the trip and can’t wait to return and begin the slow process of moving from seeds to installed plants. We are excited for you to watch the Traveler’s Garden evolve and slowly transform from a blank slate to a functioning woodland filled with serpentine savanna, barren and forest habitats. The object of the Traveler’s Garden is for you to take part in this journey, to be able to walk in our footsteps and see amazing plants that you might otherwise never have the opportunity to meet growing in a close representation of their natural environs. Thank you for your support and your love of Heronswood.

– Dr. Patrick McMillan, Director