Yellow Cream Sacs

Castilleja rubicundula ssp. lithospermoides
NATIVE

Description (Jepson, PlantID.net)

• Eudicotyledon
  • Eudicots are a major lineage of flowering plants; see family for general characteristics
• Broomrape Family (Orobanchaceae)
• Annual herb, semi-parasitic
  • Hairy and glandular (sticky)
• Leaves
  • Alternate (1 leaf at each junction with stem), with blades attached directly to the stem (sessile)
  • Lance-shaped
• Flowers
  • Inflorescence (flower arrangement) is a dense spike (single stem bearing stalkless flowers)
    • Bracts (modified leaves) at base are green and lobed
  • Bilaterally-symmetrical flowers are yellow
    • Tube-shaped, partially covered by bracts and sepals (usually green, outer flower parts)
    • 5 petals in two sets
      • 2-lobed upper lip creates a straight beak (a slender projection)
      • Lower lip forms 3 inflated pouches
    • Stigma (pollen-receiving part of the pistil/female structure) exserted atop the beak
  • Ovary superior (above the attachment of other flower parts)
• Fruit is a capsule
• Height to 28 in.

Distribution

• Native to California
  • Grows in grasslands
  • 55-64% 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
• Outside California, grows in southwestern Oregon
• Grows at elevations to 2,950 ft.

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

• Wildlife
  • Larval food source (host) for several butterfly species, e.g. common buckeye (Junonia coenia), Leanira checkerspot (Chlosyne leanira), variable checkerspot (Euphydryas chalcedona), and the endangered Bay checkerspot (E. editha bayensis)
  • Yellow cream sacs play a role, along with other related owl’s-clovers (see chart), in efforts to re-establish the Bay Checkerspot Butterfly at Edgewood
• Native people
  • Harvested the seeds of Castilleja species, which were an important food source (Anderson 2005)
    • Flowers were used in ceremonial wreaths

Name Derivation

• Castilleja (kas-til-AY-ha) – named for Domingo Castillejo Muñoz (1744-1793), a Spanish surgeon and professor of botany
• rubicundula (roo-bee-KUND-yoo-la) – from the Latin rubicunda, “reddish”
• lithospermoides (lith-oh-sper-MOI-dees) – from the Greek lithos, “stone,” and sperma, “seed”

Notes

• Partial root parasite (hemiparasitic)
  • Capable of photosynthesis, but obtains nutrients and water from a variety of other plants (Heckard 1962)
  • Specialized root structures called haustoria (singular, haustorium) penetrate the host plant’s roots
• Plants in the genus Castilleja are known to hybridize
• Formerly in the Figwort family (Scrophulariaceae)
• Edgewood’s yellow cream sacs is classified as a subspecies
  • Subspecies indicates a geographically-separated population with distinct morphological characteristics; when not isolated, interbreeding is possible
  • Variety indicates a population with small morphological variations, e.g. color, seen throughout the geographic range of the species; interbreeding is possible
  • In practice, botanists have not consistently applied these ranks

ID Tips

• May be confused with 3 other grassland Castilleja species at Edgewood: dense-flowered owl’s-clover (C. densiflora ssp. densiflora), purple owl’s-clover (C. exserta ssp. exserta), and valley tassels (C. attenuata)

	Dense-flowered Owl’s-clover	Purple Owl’s-clover	Valley Tassels	Yellow Cream Sacs
Hairiness	slightly hairy	densely hairy (cobwebby)	slightly hairy	hairy
Inflorescence	dense spike	dense spike	narrow spike	bulging spike
Flower
Sepal Color	green to pink … light pink tips	magenta … pink tips	green … white or yellow tips	green
Petal Color	mostly white with pink … yellow and purple accents	white and magenta or pink … yellow and purple accents	white to pale yellow … yellow and purple accents	bright yellow to cream
Pouch¹	inflated	inflated	slightly inflated	greatly inflated
Beak²	straight … not hairy	hooked … densely hairy	straight … not hairy	straight … not hairy

At Edgewood

• Found in serpentine and non-serpentine grasslands
  • See iNaturalist for observations of Castilleja rubicundula
• Flowers April – 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.

Anderson, M.K. 2005. Tending the Wild. University of California, Berkeley.

Heckard, L.R. 1962. Root parasitism in Castilleja. Abstract. Botanical Gazette 124(1). The University of Chicago Press Journals.

Mason, J. 2004. Scrophulariaceae — Figwort family characteristics [Illustration of owl’s clover beak, adapted]. T. Corelli. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California. (c) CC BY NC 3.0.

Miller, L.B. 2004. Castilleja attenuata [Illustration, adapted]. T. Corelli. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California. (c) CC BY NC 3.0.

—–. Castilleja densiflora ssp. densiflora [Illustration, adapted]. T. Corelli. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California. (c) CC BY NC 3.0.

—–. Castilleja exserta ssp. exserta [Illustration, adapted]. T. Corelli. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California. (c) CC BY NC 3.0.

—–. Castilleja rubicundula ssp. lithospermoides [Illustration, adapted]. T. Corelli. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California. (c) CC BY NC 3.0.

Mitchell, M. 2017. Orobanchaceae: Broomrape family — Castilleja (paintbrush & owl’s-clover). Monterey County Wildflowers, Trees, and Ferns – A Photographic Guide.

Regents of the University of California. Castilleja exserta subsp. exserta [Illustration of beak, adapted]. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.

—–. Castilleja rubicundula subsp. lithospermoides [Illustration of beak, adapted]. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.

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(2): 85-104. BioOne Complete. PDF hosted by San Diego State University, San Diego, California.