Mirabilis multiflora aka Froebel's Four O'clock

Mirabilis multiflora is a perennial in the Nyctaginaceae family. Its common names include Colorado four o'clock and four o'clock plant. It grows in the southwestern United States and Mexico. Kew places its native range from southeastern Utah to northeastern Mexico. It lives in desert and dry shrubland, among other habitats. It is not native to Britain or Ireland.

The plant reaches about 3.3 feet [1 metre] in height. In the wild, it grows on hillsides and mesas. It often grows among rocks and shrubs. It also occurs in pinyon-juniper woods and ponderosa pine forests. These sites include both sandy and gravelly ground. Recorded elevations range from about 984 to 7,546 feet [300–2,300 metres]. Its perennial growth relies on tubers, which gardeners can lift for winter storage.

Plants for a Future gives July to August as its flowering season. Plants can bloom in their first year from seed. Each flower has both male and female organs. The supplied species accounts give no flower colour or fruit details. They also lack species-level descriptions of leaves, stems and bark. The RHS describes such traits for the genus only.

For garden beds, use fertile soil that drains well. The plant accepts sandy, loamy and clay soils. It can grow in mildly acid, neutral or mildly alkaline ground. Give it full sun or shade for part of the day. Plants for a Future says it prefers moist soil. This differs from the dry habitats noted in its native range. That source lists USDA zones 7–10 and tolerance near 14°F [−10°C] in a suitable site. It also warns that frost can harm it in Britain. Gardeners there can grow it as an annual or lift the tubers. Store lifted tubers somewhere cool and free from frost. Sow seed under glass in spring, then plant out after frost. Spring division offers another way to raise plants.

Plants for a Future records food and medicinal uses for the root. Dried root powder has been mixed with cereal flour for bread. The account links this use with reduced appetite. It also records root use for stomach discomfort and poultices for swellings. These are reports of traditional use, not proof of safe treatment. Large amounts reportedly cause intoxication, and historical use included inducing visions. Although the source lists no known hazards, those effects warrant caution. The supplied evidence gives no species-level pest or disease details. Plants for a Future does not flag the species as weedy.