Serpentine Leptosiphon

Serpentine Linanthus
Leptosiphon ambiguus
NATIVE – CA ENDEMIC

Description (Jepson, PlantID.net)

• 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.

Distribution

• 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

Notes

• 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 Leptosiphon	Small-flowered Leptosiphon	Common Leptosiphon	Flax-flowered Leptosiphon	Narrow-leaved Flax
Inflorescence	few-flowered spray	many-flowered head	many-flowered head	few-flowered spray	few-flowered spray
Flower Shape	flat, open-face … funnel	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 Color	lavender to pink	white to cream¹ … often with 2 red dots at yellow base	pale lavender to pink	white … purple veins	white to blue … purple veins
Pollen Color	yellow-orange	yellow-orange	yellow-orange	yellow-orange	blue

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.