Growing native seeds for restoration: Seed dormancy and germination of sidalcea malviflora ssp. Virgata (Malvaceae)

Abstract

Sidalcea malviflora ssp. virgata (rose checkermallow) is a native forb in the Pacific Northwest, USA; it is a common species in upland prairies of the Willamette Valley, Oregon, and is a state listed endangered species in Washington State. This species provides a high value nectar supply for butterflies in this region, including the endangered Icaricia icarioides fenderi (Fender's blue butterfly), and is therefore targeted for inclusion in habitat restoration projects throughout the region. In past propagation efforts, S. malviflora ssp. virgata has demonstrated poor germination, indicating that there may be some dormancy in seeds of this species. We characterized dormancy and developed germination protocols to support greenhouse propagation of plants for habitat restoration projects. Sidalcea malviflora ssp. virgata has physical dormancy and may have some physiological dormancy as well. Highest germination (55%) was achieved by scarification followed by four weeks or more of cold moist stratification at 5 °C.