Serpentine Leptosiphon

Serpentine Leptosiphon © AFengler

Serpentine Linanthus
Leptosiphon ambiguus

Description (Jepson,

  • Eudicotyledon
    • Eudicots are a major lineage of flowering plants; see family for general characteristics
  • Phlox Family (Polemoniaceae)
  • Annual herb
  • Stem generally erect, threadlike, and branching
  • Leaves
    • Opposite (2 leaves at each junction with stem), appearing whorled
      • Small pairs are widely-spaced along stems
    • Palmately compound (separate leaflets radiating from a single point) with deeply-cleft, needle-like leaflets
  • Flowers
    • Inflorescence (flower arrangement) usually solitary from leaf axil (junction with stem) or a few-flowered cyme (a flower cluster on which the central or terminal flower blooms first)
      • Long flower stalks (peduncles) to 2 in.
    • Funnel-shaped flower with 5-petaled, dish-like face (salverform)
      • Petals lavender to pink
      • Throat ringed white to yellow, with violet below
      • Stamens (male flower parts) with yellow-orange pollen are exserted (extending beyond petals)
    • Ovary superior (above the attachment of other flower parts)
  • Fruit a capsule (a dry, multi-chambered fruit that splits open at maturity)
  • Height to 8 in.


  • Native and endemic (limited) to California
    • Grows in valley grassland, foothill woodland, and northern coastal scrub, generally on serpentine soils
    • 95% of plants occur on ultramafic soils, e.g.serpentine; see ultramafic affinity rankings (Calflora 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: 4.2 (Watch list: limited distribution or infrequent throughout a broader area in California)
  • Grows at elevations to 3,280 ft.

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

  • No documented wildlife or human uses found for this species

Name Derivation

  • Leptosiphon (lep-toe-SY-fon) – from the Greek leptos, “slender,” and siphon, “tube”
  • ambiguus (am-BIG-yoo-us) – from the Latin ambiguus,  “uncertain” or “ambiguous,” possibly referring to its uncertain relationship with other Leptosiphons with more typical, compact flowerheads


  • Previously in the genus Linanthus
    • Linanthus – from the Greek linon, “flax,” and anthos, “flower”
    • Often still used in common names for Leptosiphon species

ID Tips

  • May be confused with 3 other species of Leptosiphon at Edgewood, along with one non-native member of the Flax family (Linaceae), narrow-leaved flax (Linum bienne)
    • Small-flowered leptosiphon (L. parviflorus), Edgewood’s most common species 
    • Common leptosiphon (L. androsaceus)
    • Flax-flowered leptosiphon (L. liniflorus)
Serpentine LeptosiphonSmall-flowered LeptosiphonCommon LeptosiphonFlax-flowered LeptosiphonNarrow-leaved Flax
Inflorescencefew-flowered spraymany-flowered headmany-flowered headfew-flowered sprayfew-flowered spray
Flower Shape flat, open-face

flat, open face

very long, narrow funnel
flat, open face

long, narrow funnel
cupped to open face

short funnel 
cupped to open face

no funnel
Floral Tube Length≤ 0.24 in.≤ 1.8 in≤ 1.3 in≤ 0.08 in.
Petal Colorlavender to pinkwhite to cream¹

often with 2 red dots at yellow base
pale lavender to pinkwhite

purple veins
white to blue

purple veins
Pollen Coloryellow-orangeyellow-orangeyellow-orangeyellow-orangeblue
¹ Edgewood’s small-flowered leptosiphons are creamy white, but the species can also be pink, purple, or yellow

Serpentine Leptiosiphon (LL), Small-flowered Leptosiphon (LM), Common Leptosiphon (M), Flax-flowered Leptosiphon (RM), Narrow-leaved Flax (R)
© AFengler (LL, LM, R), SBernhard (M), KKorbholz (RM)

Serpentine Leptiosiphon (LL), Small-flowered Leptosiphon (LM), Common Leptosiphon (M), Flax-flowered Leptosiphon (RM), Narrow-leaved Flax (R)
© See Specific References

At Edgewood

  • Found in serpentine grasslands
    • No iNaturalist observations are documented because locations of rare species are obscured
  • Flowers March – June

See General References

Specific References

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

Safford, H.D. 2010, Oct. & 2011, Jan. Serpentine endemism of the California flora. Fremontia 38/39: 32-39.

Safford, H.D. and J.E.D. Miller. 2020. An updated database of serpentine endemism in the California flora. Madroño 67: 85-104. BioOne Complete.