Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicotyledons

Order: Malvales

Family: Malvaceae -- mallow

Variety: Depending on the taxonomist, Palouse plants are S. oregana ssp. oregana var. procera or S. oregana var. procera and are common.

Common Name: Oregon checkermallow, Oregon checkerbloom

Species Code: SIOR

Origin: Native to moist, open places from shrub-steppe to open pine forests east of the Cascade Mountains of south central British Columbia, Washington, Oregon, extending into Idaho, Montana and Nevada.

Rare: The species as a whole is common, but see below for more information.

Form: forb, perennial from a thick woody taproot; stems erect, 20-150 cm tall, glabrous or with simple to stellate hairs near the base.

Mature height: 14-40 inches

Duration: perennial

Longevity: medium life-span

Habitat Type: prairie

Wetland Indicator Status: FACW-

Leaves: basal leaves cordate, long petiolate, shallowly lobed; cauline leaves palmately 5-7 lobed, usually stellate-pubescent, petioles reduced upward.

Flowers: borne in an open raceme on pedicels about 3 mm long; calyx 6-9 mm long, variously pubescent, sepals 5; petals 5, light to deep pink, 1-2 cm long.

Flower color: pink

Bloom: June, July

Bloom starts on: late June

Bloom ends on: mid July

Fruit: carpels 2.5-3 mm long, reticulate-rugose, containing a single seed.

Characteristics:
Reproduces sexually by seed.
Sidalcea oregana (Nutt. ex Torr. & Gray) Gray ssp. oregana var. procera C.L. Hitchc.
Sidalcea oregana (Nutt. ex Torr. & Gray) Gray var. procera C.L. Hitchc.
The species has been divided into a number of subspecies and varieties. Depending on the taxonomist, Palouse plants are S. oregana ssp. oregana var. procera or S. oregana var. procera and are common.
S. oregana ssp. oregana var. calva (or S. oregana var. calva) is endemic to the Wenatchee Mountains and is listed as "endangered" under the Endangered Species Act (Washington State Department of Natural Resources 2009).
158,325 seeds/lb (USDA NRCS Pullman Plant Materials Center 2005).
Taprooted.
2n=20, 40 for ssp. oregana var. procera (Hitchcock et al 1969).
2n=20, 40 for ssp. oregana (Baldwin et al 2004).
Diploids, tetraploids, and hexaploids occur within the species as a whole.
S. oregana ssp. oregana var. calva is a hexaploid, 2n=60 (Hitchcock et al 1969).
Plants are gynodioecious, some plants having only perfect flowers and other plants having only pistillate flowers.
Fruit is a 1 seeded carpel.
S. oregana ssp. spicata is pollinated by insects. Bombus flavifrons, B. bifarius and Diadasia nigrafrons are the most frequent visitors to flowers. Bee flies (Bombyliidae, Diptera) and skippers (Hesperiidae, Lepidoptera) are also common. A number of other species, particularly small bees, are infrequent visitors (Ashman & Stanton 1991).
For ssp. spicata, the perfect flowers are protandrous but can be self fertilized. They tend to be larger than the pistillate flowers, although both morphs have equal numbers of flowers (Ashman & Stanton 1991, Ashman 1992, Ashman 1994a, Ashman 1994b). Female flowers have shorter petals, remain open longer, and are receptive of pollen for a longer period (Ashman & Stanton 1991).
Deer will occasionally browse the plants. Weevils sometimes feed on the seed.

Sun requirement: full sun to partial shade

Soil moisture: mesic

Precipitation: 10-28 inches for the species (USDA NRCS PLANTS Database 2009).

Sowing time: fall

Transplant time: spring

Stratification: cold moist stratification might increase germination

Seed yield: medium

Seed harvest: medium difficulty

Seed first harvest: second season

Seed cleaning: medium difficulty

Planting duration: medium

Seed insect problem: none noted

Seed shatter: medium

Seed size: medium

Seed harvest date: early Aug

Seed comments: subject to lodging

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native upland or wetland perennial forb

Propagation:
Seeds are non-dormant (Hoffman 1985).
For ssp. spicata, selfed seed has lower germination in the greenhouse than outcrossed seed. Seed from female flowers had higher germination than seed from perfect flowers in the greenhouse but not in the field. There is no difference between the two morphs in plant size at 1 week or survival after 3 months. Plants from selfed seed grow more slowly. In the field, seed tends to germinate in gopher disturbances (Ashman 1992).
Preliminary data from the USDA NRCS Pullman Plant Materials Center indicates that stratification results in slightly higher germination, but germination is still low. Scarified seed did not germinate.
Reproduces sexually by seed.

Notes: Sidalcea oregana has great looking pink flowers which attract hummingbirds. The stems may grow to 3 feet or more, but it does tend to fall over. Has a long bloom period when moisture is available. Blooms in July. Common names include Oregon checker-mallow, wild hollyhock (Skinner et al 2005).

References:
Ashman, Tia-Lynn, and Irene Baker. 1992. Variation in Floral Sex Allocation with Time of Season and Currency. Ecology 73:1237-1243.

Ashman, Tia-Lynn, and Maureen Stanton. 1991. Seasonal Variation in Pollination Dynamics of Sexually Dimorphic Sidalcea oregana ssp. spicata (Malvaceae). Ecology 72:993-1003.

Ashman, Tia-Lynn. 1992. The Relative Importance of Interbreeding and Maternal Sex in Determining Progeny Fitness in Sidalcea oregana ssp. spicata, a Gynodioecious Plant. Evolution 46:1862-1874.

Ashman, Tia-Lynn. 1994a. A Dynamic Perspective on the Physiological Cost of Reproduction in Plants. The American Naturalist 144:300-316.

Ashman, Tia-Lynn. 1994b. Reproductive Allocation in Hermaphroditic and Female Plants of Sidalcea oregana ssp. spicata (Malvaceae) Using Four Currencies. American Journal of Botany 81:433-438.

Ashman, Tia-Lynn. 2002. The Role of Herbivores in the Evolution of Separate Sexes from Hermaphroditism. Ecology 83:1175-1184.

Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 12/14/09 online at http://ucjeps.berkeley.edu/interchange.html

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Hoffman, George R. 1985. Germination of Herbaceous Plants Common to Aspen Forests of Western Colorado. Bulletin of the Torrey Botanical Club 112:409-413.

Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005. Characteristics and Uses of Native Palouse Forbs in Landscaping. USDA NRCS Pullman Plant Materials Center and Palouse Prairie Foundation. Online at http://www.wsu.edu/pmc_nrcs/Docs/Forbs_for_Landscaping.pdf

USDA NRCS, Pullman Plant Materials Center. 2005. Seed Weights of Some Palouse Native Species. Pullman Plant Materials Center, Pullman, Washington. Online at http://www.wsu.edu/~pmc_nrcs/Docs/Seed_Weights_Palouse_Native_Species.pdf

USDA NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 14 December 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Washington State Department of Natural Resources, Washington Natural Heritage Program. 2009. List of Plants Tracked by the Washington Natural Heritage Program. Accessed 12/14/09 online at http://www1.dnr.wa.gov/nhp/refdesk/lists/plantrnk.html

Links:
Plant Profile from the USDA PLANTS Database
Species information from the University of Washington Herbarium