Geranium maculatum, 2020 Wildflower of the Year

By Elaine Mills, Extension Master Gardener
Photos by Elaine Mills

Geranium maculatum (wild or spotted geranium)

Geranium maculatum (wild or spotted geranium), a perennial native to eastern North America, has been chosen as the Wildflower of the Year for 2020 by the Virginia Native Plant Society. This delightful herbaceous plant can be seen in two demonstration gardens maintained by Extension Master Gardeners (Glencarlyn Library Community Garden and the Shade Garden) this month.


Wild geranium forms a foliage mound of deeply-lobed basal leaves 12 to 18 inches high by 18 inches wide. The lobes of the medium to dark green leaves can vary from 3 to 7, with a palmate (5-lobed) arrangement being the most common.


Flowers are borne in loose clusters of 2 to 5 blossoms at the tops of erect 6-inch flowering stems. The 5-petaled, saucer-shaped flowers measure about 1 ¼ inch across and range in color from pale pink to lavender to rose-purple. The petals are marked with fine, dark veins that function as nectar guides. The flowers attract a variety of native bees, including a specialist pollinator, as well as syrphid flies, butterflies, skippers, beetles, and ants. The plant also serves as the larval host for many species of Lepidoptera and provides seeds for mourning doves and quail.


Distinctive fruit resembles the bill of a crane.

Wild geranium blooms over a month-long period, locally from early April to early May. The distinctive fruit that forms three to five weeks later is said to resemble the bill of a crane, leading to the plant’s alternative common name, Cranesbill. When dry, the fruit capsule opens explosively, catapulting seeds as much as 30 feet away from the parent plant.


Wild geranium tolerates of variety of soil types and pH, although it prefers the moist, well-drained, humus-rich soils characteristic of the upland and well-drained floodplain forests of the mountain and Piedmont regions of Virginia. It is an excellent addition to lightly shaded flower borders or woodland gardens, where it combines well with other native wildflowers. In its native habitat, it is often associated with Uvularia grandiflora (large-flowered bellwort), Polygonatum biflorum (Solomon’s seal), Podophyllum peltatum (mayapple), Phlox divaricata (woodland phlox), and Trillium grandiflorum (great white trillium). In a garden setting it can also be interplanted with Aquilegia canadensis (eastern columbine) and Tiarella cordifolia (foamflower), as well as ferns such as Osmunda claytonia (interrupted fern), and violets. Wild geranium can also naturalize as a ground cover, although it does not spread aggressively.

Wild geranium naturalizes as a ground cover at the National Arboretum

If sited in full sun, wild geranium requires more moisture. The foliage may die back somewhat in hot summer weather, but can be revitalized by supplemental water and a light shearing. The plant does not suffer from any serious pests or diseases, but deer may eat the flowers and sometimes the foliage.

Geranium maculatum is an example of an evolutionary trend in flowering plants away from perfect (bisexual) flowers to unisexual (either male or female) flowers. A 1991 study conducted in Illinois and Indiana, showed that the female-only (pistallate) plants began flowering earlier than those with bisexual flowers.  A study conducted at the University of Georgia in 2006 showed that female plants produced more and larger seeds than the bisexual flowers. Their seeds were also more likely to germinate and produced larger plants. The 10 yellow stamens are fully fertile in bisexual flowers, but rudimentary and non-functional in female flowers. The stigmas of both flower types have 5 star-like branches.


Resources

  • Jon Agren and Mary F. Willson. April 1, 1991. Gender Variation and Sexual Differences in Reproductive Characters and Seed Production in Gynodioecious Geranium maculatum. Botanical Society of America.
  • Shu-Mei Chang. Feb 2006. Female compensation through the quantity and quality of progeny in a gynodioecious plant, Geranium maculatum (Geraniaceae). American Journal of Botany 93 (2): 263-70.
  • John Hayden, VNPS Botany Chair. January 22, 2020. Wildflower of the Year 2020, Wild Geranium (Geranium maculatum). Virginia Native Plant Society.
  • Susan Mahr. May 24, 2013. Wild Geranium, Geranium maculatum. Master Gardener Program, Division of Extension, University of Wisconsin – Madison.
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