Yellow Cream Sacs

Yellow Cream Sacs © DSchiel

Castilleja rubicundula ssp. lithospermoides

Description (Jepson,

    • 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.


      • 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)

        • Host plant for the larvae of several butterfly species, including common buckeye (Junonia coenia), Leanira checkerspot (Chlosyne leanira), variable checkerspot (Euphydryas chalcedona), and the endangered Bay checkerspot (E. editha bayensis)
          • 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”


            • 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 rank is used to recognize geographic distinctiveness, whereas variety rank is appropriate for variants seen throughout the geographic range of the species; in practice, these two ranks are not distinct

            ID Tips

              Dense-flowered Owl’s CloverPurple Owl’s CloverValley TasselsYellow Cream Sacs
              Hairinessslightly hairydensely hairy (cobwebby)slightly hairyhairy
              Inflorescencedense spikedense spikenarrow spikebulging spike
                 Sepal Colorgreen to pink

              light pink tips

              pink tips

              white or yellow tips

                 Petal Colormostly 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
                 Pouch¹inflatedinflatedslightly inflatedgreatly inflated

              not hairy

              densely hairy

              not hairy

              not hairy
              ¹ Pouch: 3 lower fused petals
              ² Beak: 2 upper fused petals
              Dense-flowered Owl’s Clover (L), Purple Owl’s Clover (LM), Valley Tassels (RM), Yellow Cream Sacs (R)
              © DSchiel (L, LM, R), TCorelli (RM)
              Dense-flowered Owl’s Clover (L), Purple Owl’s Clover (LM), Valley Tassels (RM), Yellow Cream Sacs (R)
              © See Specific References

              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, vol. 38:4/39:1, pp. 28-31.

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

                      Mason, J. 2004. Owl’s clover beak [Illustration, adapted]. In 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, Castilleja densiflora ssp. densiflora, Castilleja exserta ssp. exserta, and Castilleja rubicundula ssp. lithospermoides [Illustrations]. In 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-castilleja. Monterey County Wildflowers, Trees, & Ferns – A Photographic Guide.

                            Regents of the University of California. Castilleja exserta subsp. exserta. [illustration of beak, adapted] in Jepson Flora Project (eds.). Jepson eFlora.

                              —–. Castilleja rubicundula subsp. lithospermoides. [illustration of beak, adapted] in Jepson Flora Project (eds.). Jepson eFlora.

                                Safford, H.D. 2010, Oct. & 2011, Jan. Serpentine Endemism of the California Flora. Fremontia, vol. 38:4/39:1, pp. 32-39.

                                  Safford, H.D. and Miller, J.E.D. 2020. An Updated Database of Serpentine Endemism in the California Flora. Madroño, 67(2), pp. 85-104.