![](https://i0.wp.com/friendsofedgewood.org/wp-content/uploads/valley-tassels_tcorelli.jpg?resize=261%2C512&ssl=1)
Narrow-leaved Owl’s-clover
Castilleja attenuata
NATIVE
Description (Jepson, PlantID.net)
- 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.
Distribution
- 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)
- Owl’s-clovers play a major role in efforts to re-establish the Bay Checkerspot Butterfly at Edgewood
- 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
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)
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 yellow cream sacs (C. rubicundula ssp. lithospermoides)
- Valley tassels is the only one of these with mainly white flowers
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 |
² Beak: 2 upper fused petals
![](https://i0.wp.com/friendsofedgewood.org/wp-content/uploads/castellija_dschiel-dens-purple-cream_tcorelli-valley_combo.jpg?resize=1000%2C311&ssl=1)
© DSchiel (L, LM, R), TCorelli (RM)
![](https://i0.wp.com/friendsofedgewood.org/wp-content/uploads/owls-clover_illustration-combo.jpg?resize=1000%2C355&ssl=1)
© JMason and © LMiller and © Regents of the University of California
At Edgewood
- Found in grasslands
- See iNaturalist for observations of this plant
- Flowers April – May
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. 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.
Miller, L.B. 2004. 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.
Miller, L.B. 2004. 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.
Miller, L.B. 2004. 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.
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]. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.
Regents of the University of California. Castilleja rubicundula subsp. lithospermoides [Illustration of beak, adapted]. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.
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.
General References
Calflora Database. 2014. Berkeley, California.
Calscape. 2018. California Native Plant Society.
Charters, M.L. 2015. California Plant Names: Latin and Greek Meanings and Derivations.
Charters, M.L. 2017. Southern California Wildflowers: Guide to the Pronunciation of Specific, Generic and Family Names.
Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.
Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.
Flora of North America. efloras.org.
Harris, J.G. and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.
Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.
Native American Ethnobotany DB.
Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.