Woodland Monolopia

Woodland Monolopia © GBarton

Woodland Woollythreads
Monolopia gracilens

Description (Jepson, PlantID.net)

  • Eudicotyledon
    • Eudicots are a major lineage of flowering plants; see family for general characteristics
  • Sunflower Family (Asteraceae)
  • Annual herb
  • Stems slender and branching
  • Leaves
    • Opposite at base, then alternate
    • Linear to ovate, sometimes toothed
    • Woolly
  • Flowers
    • Inflorescence (flower arrangement) of one or several radiate heads (see Sunflower family)
      • 7-11 yellow female (pistillate) ray flowers, sometimes slightly lobed
      • Numerous bisexual disk flowers, creating a central, golden-yellow dome
    • Phyllaries (vase-like floral bracts, collectively called the involucre) 7-11, in 1 series (rank), 1 per ray flower
    • Ovary inferior (below the attachment of other flower parts)
  • Fruit is an achene (a single-seeded, dry fruit that does not split open)
  • Height to 31 in.
Phyllaries © DSchiel


  • Native and endemic (limited) to California
    • Grows in serpentine grassland, chaparral, and oak woodland
    • 55-64% of plants occur on ultramafic soils, e.g. serpentine; see ultramafic affinity rankings (Calfora per Safford and Miller 2020)
    • See Serpentine Grassland for more about Edgewood’s serpentine soil and the unique communities it supports
    • See Calflora for statewide observations of this plant
  • California Rare Plant Rank: 1B.2 (rare, threatened, or endangered in California and elsewhere)
    • The genus Monolopia is endemic (limited) to California, and M. gracilens grows only in the Bay Area and into the South Coast Ranges
  • Grows at elevations between 330 ft. and 3,940 ft.

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

  • No documented wildlife or human uses found for this species

Name Derivation

  • Monolopia (mon-oh-LO-pee-a) – from the Greek monos, “one,” and lopos, “covering,” describing the single row of phyllaries
  • gracilens (gra-SIL-ens) – from the Latin gracieux, meaning “graceful” or “slender”
  • Woodland monolopia – Despite its common name, woodland monolopia grows in a variety of habitats within its limited range


  • Woolly hairs on leaves reflect harsh sun rays and help maintain humidity
Flowers © GBarton

ID Tips

  • May be confused with goldfields (Lasthenia species), also in the Sunflower family, but the stout stems and thick, woolly leaves of woodland monolopia are very distinctive.

At Edgewood

  • Found in chaparral along the Clarkia trail
    • No iNaturalist observations are documented because locations of rare species are obscured
  • Flowers April – June

See General References

Specific References

Alexander, E.B. 2010, Oct. and 2011, Jan. Serpentine soils and why they limit plant survival and growth. Fremontia 38/39: 28-31.

Safford, H.D. and J.E.D. Miller. 2020. An updated database of serpentine endemism in the California flora. Madroño 67(2): 85-104. BioOne Complete. PDF hosted by San Diego State University, San Diego, California.