Mirabilis macfarlanei

Common Names:
MacFarlane's four-o'clock
Constance & Rollins
Growth Habit:
CPC Number:
Profile Contributors:
Edward Guerrant, Ph.D.
Fully Sponsored

Reference Links

ITIS - Tropicos - USDA Plants - Fish & WildLife

Participating Institutions

The following Participating Institutions are custodians for this species in the CPC National Collection:
Rae Selling Berry Seed Bank & Plant Conservation Programs
Cincinnati Zoo & Botanical Garden

The conservation of Mirabilis macfarlanei is fully sponsored.
Edward Guerrant, Ph.D. contributed to this Plant Profile.


This showy plant is quite something if you encounter it in the dry areas of Eastern Oregon and Western Idaho. Often growing on dry, steep slopes high above the river, this four-o'clock, with bright magenta flowers and purplish stems, stands out on the brownish hillsides.

Mirabilis macfarlanei was listed as Endangered by the US Fish and Wildlife Service in 1979. It was threatened by many things, including: trampling, grazing, disease, insect damage and horticultural collecting. An initial recovery plan was created in 1985. It called for baseline studies, determination of population trends, and periodic sampling of populations. The species was downlisted to Threatened in 1996 due to the discovery of additional populations and successful recovery efforts. A revised recovery plan was finalized in 2000.

The protection of Mirabilis macfarlanei is especially important because it is host to a rare moth that was discovered in 1983. This Heliodinid moth (Lithariapteryx sp.) is host specific to M. macfarlanei. The moth larvae only feeds on the leaves and flowers of Mirabilis macfarlanei (Baker 1985). In the interests of biodiversity, it is important to preserve both the rare moth and the rare four-o'clock. Because the moth's feeding preferences have the capability of reducing reproduction of the four-o'clock, it is important to protect large numbers of plants. With larger numbers of plants, there will be a greater chance for plants to reproduce.

Above ground, the plant does not look very large. It may consist of a few trailing branches up to a couple of feet across. However, underground, the plant has a thick taproot that may grow up to 8 feet deep! This large underground structure enables it to remain dormant in poor growth years or to recover from above ground disturbances. For example, in 1997, an accidental herbicide spraying by the county weed management board in Idaho severely impacted several thousand stems of Mirabilis macfarlanei on both federal and private land. At least 2,750 of the stems on federal land showed heavy damage from the spraying, but in 1998, monitoring showed that many of the plants had survived (USFWS 2000). The long-term effects are unknown. Seeds collected that year from the affected populations smelled strongly of herbicide, indicating that the herbicide may have impacted seeds produced that year (Andrea Raven, pers. comm. 2001).

The species was named after Ed MacFarlane, who was a riverboat pilot on the Snake River for over 30 years. Ed MacFarlane did not discover the species. It was shown to him by Harold St. John, a botanist, on a trip up the Snake River. For unknown reasons, St. John did not publish his find. Later, Ed MacFarlane showed two other botanists, Lincoln Constance and Reed Rollins, the plant. They described the species and named it after the pilot (Pilz 1978 in Kaye and Meinke 1992).

Distribution & Occurrence


Conservation, Ecology & Research