Sticky Monkeyflower

Orange Bush Monkeyflower, Island Monkeyflower
Diplacus aurantiacus
NATIVE

Description (Jepson, PlantID.net)

• Eudicotyledon
  • Eudicots are a major lineage of flowering plants; see family for general characteristics
• Lopseed Family (Phrymaceae)
• Evergreen shrub
• Leaves
  • Opposite (2 leaves at each junction with stem)
  • Narrow, dark green, and leathery, with prominent veins
  • Edges often curled under
  • Hairs on paler undersurface
  • Distinctly sticky!
• Flowers
  • Inflorescence (flower arrangement) of 2-4 yellow-orange flowers at the leaf axils (junction with stem)
  • Long, narrow, calyx tube is hairless (glabrous)
    • Calyx is the collective term for sepals (usually green, outer flower parts)
  • Pedicel (stalk of a single flower) is shorter than the calyx
  • Trumpet-shaped, bilaterally-symmetric, with 5 fused petals
    • 2 upper lobes stand upright
    • 3 lower lobes, often with nectar-guide markings, create a landing platform for pollinators
  • Ovary superior (above the attachment of other flower parts)
• Fruit a capsule (a dry, multi-chambered fruit that is dehiscent [splits open]) with 1 seed
• Height to 4 ft.

Distribution

• Native to California
  • Grows on rocky hillsides, canyon slopes, disturbed areas, chaparral margins, and open woodlands
  • Tolerates serpentine soil
  • See Calflora for statewide observations of this plant
• Outside California, grows from southwestern Oregon south into Baja California, Mexico
• Grows at elevations to 2,625 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

• Wildlife
  • Nectar source for insects and hummingbirds
  • Larval food source (host) for common buckeye (Junonia coenia) and variable checkerspot butterfly (Euphydryas chalcedona)
• Native people
  • Ate the young leaves as salad greens (Ritter 2015)
  • Used to treat sores, burns, diarrhea, and eye irritation

Name Derivation

• Diplacus (DIP-la-kus) – from the Greek di, “two,” and plax/plakos, “a disk,” referring to the double placenta of the seed capsule (Ritter 2015)
• aurantiacus (aw-ran-ti-AYE-kus) – from the Latin for “orange”
• Sticky – refers to the resinous leaves
• Monkeyflower – flower shape suggests a mime or monkey
  • Sticky monkeyflower used to be in the genus Mimulus, named possibly
    • From the Greek mimo, “ape,” because markings on the flowers (or seeds) resemble the face of a monkey
    • Or from the Latin mimus, “an actor or mimic,” because the flower resembles the mouthpiece of a grinning mask worn by classical actors

Notes

• Leaves are adapted to dry, hot summers of our Mediterranean climate
  • Sticky resins help conserve water, as well as prevent browsing
  • Curled edges and hairy undersurface limit the loss of water from heat, cold, and wind
• Two-part stigma (pollen-receiving part of the pistil/female structure) closes when touched to capture pollen carried by arriving pollinator and to prevent self-pollination as the pollinator backs out (Breckling 2008)
  • If pollen from another flower has not been deposited, the stigma will continue to open and close until pollen is finally received (Borenstein 2010)
  • You can induce this closing by lightly pressing the center of the stigma with a fingernail or pencil tip; the stigma will reopen in a few moments
• Diplacus vs Mimulus – In 2018, the scientific name for sticky monkeyflower changed from Mimulus aurantiacus to Diplacus aurantiacus

ID Tips

• Check out this short Jepson video for tips on identifying sticky monkeyflower, called here by an alternative common name, orange bush monkeyflower
  • At 1:52 min. into the video, you can see the stigma close when touched
• Edgewood has 3 other monkeyflowers: the diminutive purple mouse-ears (Diplacus douglasii), small-leaved monkeyflower (Erythranthe microphylla), and seep monkeyflower (Erythranthe guttata)

	Purple Mouse-ears	Small-leaved Monkeyflower	Seep Monkeyflower	Sticky Monkeyflower
Growth Habit	annual herb	annual herb	perennial herb	shrub
Height	≤ 1.6 in.	≤ 1 ft.	≤ 2 ft.	≤ 4 ft.
Flowers	magenta with gold-striped throat	yellow	yellow with orange-red spots	yellow-orange
Leaves	ovate	elliptic to round	ovate to round	narrowly elliptic to linear
Habitat	usually serpentine barrens	seeps and streambanks	seeps and swales	coastal scrub, chaparral, woodland openings
Trails	upper Clarkia and upper Sunset	upper woodland of Edgewood	lower Clarkia	common, especially on lower Clarkia

At Edgewood

• Found commonly in coastal scrub and open woodlands
  • See iNaturalist for observations of this plant
• Flowers March – July

See General References

Specific References

Borenstein, C. 2010. Mimulus: Masses of Monkeyflowers.

Breckling, B. 2008. Spring Wildflowers of Henry W. Coe State Park and the Inland San Francisco Bay Area. Pine Ridge Association.

Ritter, M. 2018. California Plants: A Guide to Our Iconic Flora. Pacific Street Publishing, San Luis Obispo, California.

Ross, E.S. 1996. Mimulus aurantiacus. Insect/plant relationships: A photographic essay. Fremontia, April 1996.