Mirabilis multiflora (Torr.) Gray

by Kyle Christie, Native Plants of Arizona 2003
Common names: Colorado four-o’clock, many flowered four-o’clock (1, 2).
Family: Nyctaginaceae (1)
Synonymy: Oxybaphus multiflora (Torr.) Gray in Torr., Allionia multiflora (Torr.) D.C. Eaton, Quamoclidon multiflorum (Torr.) Torr ex Gray (1, 2, 5).
Etymology: Mirabilis translates into “wonderful, extraordinary, or astonishing”. Multiflora translates into “many flowered” (3).

Identification
Growth form: Herbaceous perennial, sprawling, clump-forming, up to .7 M in height, up to 1 M in diameter (4).
Roots: Thick caudex (5). Roots contain ethnogenic compounds(10).
Stem: Decumbent to ascending, nodes swollen, leafy, clump-forming, 30 to 100 cm long (4, 5).
Leaves: Petiolate, thick, orbicular to ovate, 2 to 10 cm long/wide, truncate to cordate base, acute to apiculate apex, variously pubescent, light green (4, 5).
Inflorescence/flowers: Inflorescence solitary in axils and cymose at the ends of branches (5). Flowers apetalous, sepals petaloid, bracts sepaloid and forming a subtending involucre (8). Involucre 15 to 35 mm, campanulate, 5 lobed, subtending 6 to 8 pedicillate flowers. Calyx (appears as corolla) 3 to 6 cm, 5 lobed, the lobes usually 2 cleft, red to magenta to purple (4, 5). Anthers conspicuously yellow.
Fruit: Anthocarp (an achene enveloped by accrescent calyx base) 6 to 8 mm, smooth or slightly furrowed at the base (4, 5, 8).
Similar species: Mirabilis oxybaphoides smaller bracts below the inflorescence and often only one flower open at a time while M. multiflora has a very large bract below the inflorescence and often 2-3 flowers open at one time.

Ecology
Life history: Herbaceous perennial.
Native/introduced: Native to the Southwestern United States.
Photosythetic pathway:
Phenology: Flowers April to September (4, 7). Flowers open in late afternoon and wither by the following morning (9), hence the common familial name (Four-O’clock family).
Distribution: Southwestern United States and Texas to Northern Mexico. Growing in dry communities at 2,100 to 7,500 feet, especially in Pinyon-Juniper woodlands. May sometimes grow under the protection of a Pinyon pine or a Juniper in harsh, dry locations (5, 7).

Uses
Cultivated ornamental (7). Roots used as the source of a jalap substitute, a purgative (8). Navajo make dye from boiled “petals” (6). The Navajo smoke a mixture of Mirabilis and other herbs in traditional ceremonies (6). Tincture made from the roots can be used as an appetite suppressant and as a mild sedative (10).

References
1. Integrated Taxonomic Information System (ITIS) (http://www.itis.usda.gov).

2. USDA, NRCS. 2002. The PLANTS Database, Version 3.5. (http://plants.usda.gov). National Plant Data Center, Baton Rouge, Louisiana 70874-4490 USA.

3. Gledhill, D. 2002. The Names of Plants. 3rd Edition. Cambridge University Press. Cambridge, England.

4. McDougal, W.B. 1973. Seed Plants of Northern Arizona, The Museum of Northern Arizona. Flagstaff, Arizona.

5. Welsh, S. et al. 1987. A Utah Flora. Great Basin Naturalist Memoir No. 9, 1987. Brigham Young University.

6. Elmore, F.H. 1943 (1978). Ethnobotany of the Navajo. A Monograph of the University of New Mexico and The School of American Research. University of New Mexico Press.

7. Busco J. and Morin N.R. 2003. Native Plants for High Elevation Western Gardens. Fulcrum Publishing. Golden, Colorado. Published in partnership with the Arboretum at Flagstaff.

8. Zomlefer, W. 1994. Flowering Plant Families. The University of North Carolina Press. Chapel Hill and London.

9. Epple, A. O. 1995. A Field Guide to the Plants of Arizona. Falcon Publishing. Helena, Mountana.

10. Hogan, P. and Huisinga, K. 1998. An Annotated Catalog of the Native and Naturalized Flora of Arizona. Unpublished.