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 base of inflorescence 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 part of the pistil/female structure) not projecting (exserted)
    • Ovary superior (above the attachment of 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 (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)
  • 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

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 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. Abstract. 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: Broomrape family — Castilleja (Paintbrush & owl’s-clover). Monterey County Wildflowers, Trees, and Ferns – A Photographic Guide.

Press, M.C. 1998. Dracula or Robin Hood? A functional role for root hemiparasites in nutrient poor ecosystems. Oikos 82: 609-611. JSTOR.

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