Valley Tassels

Valley Tassels © TCorelli

Narrow-leaved Owl’s Clover
Castilleja attenuata

Description (Jepson,

    • Eudicotyledon
      • Eudicots are a major lineage of flowering plants; see family for general characteristics
    • Broomrape Family (Orobanchaceae)
    • Annual herb
      • Hairy and non-glandular (sticky)
    • Leaves
      • Alternate (1 leaf at each junction with stem), with blades attached directly to the stem (sessile)
      • Linear, usually with deeply-cut lobes
    • Flowers
      • Inflorescence (flower arrangement) is a narrow spike (single stem bearing stalkless flowers)
      • Bracts (modified leaves at flower base) and sepals (usually green, outer flower parts) are lobed and tipped white or yellow
      • Bilaterally-symmetrical flowers are white to pale yellow with purple and yellow accents
        • Tube-shaped, partially covered by bracts and sepals
        • 5 fused petals in two sets
          • 2-lobed upper lip creates a straight beak (a slender projection), with fine short hairs (puberulent)
          • 3-lobed lower lip forms a slender pouch with purple spots
        • Stigma (pollen-receiving structure of the female flower) not projecting (exserted)
      • Ovary superior (attached above other flower parts)
    • Height to 20 in.


      • Native to California
        • Grows in grasslands, foothill woodlands, chaparral, and mixed evergreen forests
        • See Calflora for statewide observations of this plant
      • Outside California, grows from British Columbia, Canada to northern Baja California, Mexico
      • Grows at elevations to 5,250 ft.

      Uses (Picking or removing any natural material from public land is illegal)

        • 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)
        • Native people harvested the seeds of owl’s clovers (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
          • attenuata (a-ten-yoo-AY-ta) from the Latin attenuāre, “to make thin, reduce,” referring to the slender growth habit


            • 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)

            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 cream sacs (C. rubicundula ssp. lithospermoides)
                • Valley tassels is the only one of these with mainly white flowers
              Dense-flowered Owl’s CloverPurple Owl’s CloverValley TasselsCream 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), Cream Sacs (R)
              © DSchiel (L, LM, R), TCorelli (RM)
              Dense-flowered Owl’s Clover (L), Purple Owl’s Clover (LM), Valley Tassels (RM), Cream Sacs (R)
              © See Specific References

              At Edgewood

                • Found in grasslands
                • Flowers April – May

                See General References

                Specific References

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

                    Heckard, L.R. 1962. Root Parasitism in Castilleja. Botanical Gazette 124:1.

                      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.

                            Press, M.C. 1998. Dracula or Robin Hood? A Functional Role for Root Hemiparasites in Nutrient Poor Ecosystems. Oikos, 82:3, pp. 609-611.

                              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.

                                  Shapiro, A.M. and Manolis, T.D. 2007. Field Guide to Butterflies of the San Francisco Bay and Sacramento Valley Regions. University of California Press, Berkeley – Los Angeles, California.