Propagation Protocol for Callirhoe involucrata

Keywords
Malvaceae, seed propagation, scarification, physical dormancy, wine cups, purple poppymallow

Nomenclature
USDA NRCS (2002)

Rocky Mountain Native Plants Company (RMNP) is located in Rifle, Colorado. Currently,we are producing more than 2500000 native plants representing approximately 250 different species. RMNP produces and installs native plant materials from a wide range of habitats for restoration projects and for the growing landscaping industry that demands hardy, attractive native plant materials.

One species we grow, Callirhoe involucrata (Torr.& Gray) Gray(Malvaceae), commonly known as wine cups or purple poppymallow, is a striking herbaceous plant that is rapidly gaining popularity in the landscape and horticultural industries. It is also widely used for roadside wildflower plantings and as a reliable, drought-tolerant species for restoration projects because it readily establishes in disturbed areas with droughty soils.

One reason for its recent rise in popularity with landscapers and gardeners is its brightly colored flowers that are produced in profusion throughout the growing season. In southern portions of its range, this species can produce flowers from March to August. Callirhoe involucrata can become a large, semi-erect to sprawling plant, making it suitable for large rock gardens, in mass plantings, or along garden walls and hillsides that utilize its rambling habit. A single plant can be 60 to 90 cm (2 to 3 ft) across, and its height is typically 17 to 55 cm (8 in to 1.5 ft). Leaves are palmate and are covered with fine hairs, which add to the character of the plant. Its numerous flowers are about 3.8 to 6 cm (1.5 to 2.5 in) across. Flowers have 5 satiny petals ranging in color from deep red to magenta or rose pink. Each petal has a splotch of white at the base, which highlights the numerous, pale yellow stamens borne on rose-pink filaments that are fused into a column and surround the stigma. White-flowered forms are also seen in nature. Because this species flowers over a prolonged period, mature fruits can be harvested several times over the summer and fall months. Each schizocarp ripens from green to brown and contains many hard seeds. The small seeds are prominently net veined on each side and have a short beak. Average seed weight is 160200 seeds/kg (72800 seeds/lb), although this can vary by population.

Two botanical varieties are currently recognized. Callirhoe involucrata var. involucrata (Torr. & Gray) Gray is found throughout Wyoming, North Dakota, and Minnesota south to northern Mexico in the western and central US as well as Michigan, Pennsylvania, and Virginia. Callirhoe involucrata var. lineariloba (Torr. & Gray) Gray is found in the southwestern and southern Great Plains states and throughout Texas.

Seed Propagation

Seeds have physical dormancy and should be scarified prior to planting. At RMNP, we use a hot-water scarification treatment. Using wet heat is an effective method for many small-seeded species with hard impermeable seed coats as it provides a rapid, uniform treatment, and results of the treatment can easily be seen within a few hours. Thickness of the seed coat may vary somewhat among sources, so it is a good idea to dissect a few seeds and examine the thickness of seed coats from each lot to help determine duration of the wet-heat treatment.

Seeds are added to boiling water for only 5 to 10 s and then immediately transferred to a vat of cold water, which allows them to quickly cool and prevents embryo damage. The seeds imbibe in the cool water for 1 d and are ready for sowing without further treatment. We direct sow seeds to individual Ray Leach 164-ml (10-in³) containers and lightly cover...