Common Madia

Elegant Madia, Tarweed
Madia elegans
NATIVE

Description (Jepson, PlantID.net)

• Eudicotyledon
  • Eudicots are a major lineage of flowering plants; see family for general characteristics
• Sunflower Family (Asteraceae)
• Annual herb
  • Whole plant hairy, with gland-tipped (sticky) hairs on upper stems and leaves
  • Strongly aromatic
• Leaves
  • Blades lanceolate to linear, seldom toothed
  • Hairy and glandular (sticky), especially upper leaves
  • Lower leaves opposite (2 leaves at each junction with stem)
  • Upper leaves alternate (1 leaf at each junction with stem)
• Flowers
  • Inflorescence (flower arrangement) of large, yellow radiate flowerheads (see Sunflower family), each head with two kinds of flowers
    • Ray flowers (15-22) are yellow and female (pistillate)
      • Often have a maroon base, like the Edgewood population
    • Disk flowers (25-80+) are yellow and male (staminate), with yellow-brown anthers (pollen-producing parts)
  • Phyllaries (vase-like set of bracts, modified leaves, collectively called the involucre) are hairy and densely glandular (sticky)
    • In a single series (row), one for each ray flower
  • Ovary inferior (below the attachment of other flower parts)
    • Each ovary is enfolded, pocket-like, by a phyllary
• Fruit is an achene (a single-seeded, dry fruit that does not split open), more specifically called a cypsela because of the inferior position of the ovary
  • Only ray flowers produce fruits
    • Only 2 of 10 species in the Madia genus produce only ray fruits; the other species, M. subspicata, is not found in Edgewood
• Height to 98 in.

Distribution

• Native to California
  • Grows in open, grassy, or disturbed sites, in coarse or clay soils, including serpentine
  • See Calflora for statewide observations of this plant
• Outside California, grows in Nevada and from Washington, south into Baja California, Mexico
• Grows at elevations to 11,155 ft.

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

• Wildlife
  • Seeds are eaten by small mammals and numerous bird species, e.g. California quail (Callipepla californica), California towhee (Melozone crissalis), and dark-eyed junco (Junco hyemalis)
  • An an important late-summer nectar source for bees, butterflies, and other insects
  • Host (food source for the larval stage) for the small heliothodes moth (Heliothoides diminutiva)
• Native people
  • Seeds of tarweeds (Hemizonia and Madia species), which are abundant, aromatic, and rich in oil, were a prized component of pinole for many California native peoples (Lowry 2009)
    • Pinole is a general term for various flours made from the ground, toasted seeds of wildflowers and grasses, eaten dry or moistened and shaped into balls or cakes (Anderson 2005)
    • “Pinole” is a Hispanic version of an Aztec word
  • Harvesting, done by women moving across fields and beating seeds into baskets, could occur before or after fields were burned to stimulate regrowth (Anderson 2005, Williams 2003)
    • If fields were burned before harvesting, the seeds were already roasted when beaten from the scorched, still-standing, but no longer sticky plants (Williams 2000)

Name Derivation

• Madia (MAD-ee-a) – from the Chilean native name madi, used to refer to the coast tarweed, Madia sativa
• elegans (EL-e-gans) – from the Latin, meaning “elegant”

Adaptations

• Well-adapted, like most tarweeds, to flower and fruit during our Mediterranean climate’s long dry summers and autumns (Lowry 2009)
  • Develops deeper roots than most annuals to capture ground water before bolting
  • Trichomes (plant hairs) increase humidity
  • Mucilage (a thick, gluey substance) in stems and leaves retains moisture (Pierce 2012)
  • Late-summer blooming ensures few competitors for pollinators
• By late morning on sunny days, as the humidity decreases, common madia rolls up its flowers to protect its pollen (Pierce 2012) and opens them again in evening when humidity increases (Klamath 2015)
  • This process is an example of hydronasty, a nastic response to humidity
  • Nastic responses occur when a plant part, such as a flower or leaf, moves in response to a stimulus (Mauseth 2012), e.g., humidity (hydronasty), light (photonasty), temperature (thermonasty), or touch (thigmonasty)
    • Nastic responses are caused by changes in turgor pressure 
    • They are independent of the direction of the stimulus and usually are reversible and repeatable
  • Nastic responses differ from tropic responses
    • Tropic responses are directional growth movements–a plant grows toward or away from a stimulus, e.g., light (phototropism), gravity (gravitropism) or touch (thigmotropism)
    • All plants have tropic responses, but only some plants have nastic responses
  • Edgewood’s other tarweeds do not close diurnally
• Fruits, produced only by the ray flowers, are each cupped by a glandular (sticky) phyllary, aiding in the seed’s dispersal by catching onto passing animals
• Terpenes, a group of chemical compounds exuded from glands, deter herbivory (Grenada 2017)
  • Cattle enjoy young plants, but eschew mature, highly glandular plants, causing some ranchers to kill tarweeds (Lowry 2009)
• Terpene-exuding glands also provide an indirect defense against herbivory
  • Glandular plants are visited by various large and small herbivorous insects
  • Smaller insects, e.g., aphids and small flies, are trapped by the sticky glands and attract predatory insects, e.g., the spine-collared assassin bug (Pselliopus spinicollis)
  • Predatory insects also eat larger visiting insects, e.g., some weevils and mealybugs, and the small heliothodes moth caterpillar (Heliothodes diminutiva), that would otherwise eat the tarweed
  • In a controlled study, UC researchers found that hayfield tarweed and common madia plants with trapped insects produced more flowers and seeds (LoPresti 2017)
  • Watch this short video showing the assassin bug in action (KQED 2021)

Notes

• The Tarweed-Silversword subtribe (Madiinae) includes some 127 species, principally in California, where it likely originated, and Hawaii (Flora; Baldwin 2000)
  • California’s tarweeds are traditionally called “true tarweeds”
    • Most species are summer-flowering annuals in summer-drought habitats
    • Leaves and phyllaries are usually hairy and glandular
    • Most species have radiate heads of yellow or white flowers
    • Each phyllary cups or encloses a single ray flower
    • Anthers are usually dark
    • Chaffy bracts usually create a ring between the ray and disk flowers
  • Edgewood has 10 tarweeds in 5 genera
    • Achyrachaena species: blow-wives (A. mollis)
    • Hemizonia species: hayfield tarweed (H. congesta ssp. luzulifolia)
    • Lagophylla species: common hareleaf (L. ramosissima)
    • Layia species: tidy-tips (L. platyglossa), tall layia (L. hieracioides), and woodland tidy-tips (L. gaillardioides)
    • Madia species: common madia (M. elegans), threadstem tarweed (M. exigua), slender tarweed (M. gracilis), and coast tarweed (M. sativa)

ID Tips

• Look for the distinctive maroon color ar the base of the flowers
• This plant provides an impressive summer display in the native garden at Edgewood’s Bill and Jean Lane Education Center

At Edgewood

• Found in non-serpentine and serpentine grasslands
  • See iNaturalist for observations of this plant
• Flowers June – November

Specific References

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

Baldwin, B.G., and B.L.Wessa. 2000, Dec.1. Origin and relationships of the tarweed-silversword lineage (Compositae-Madiinea). American Journal of Botany.

California Native Plant Society Yerba Buena Chapter. The tarweeds.

Granada Native Garden Newsletter. 2017, Oct. 15. Tarweeds — and their evil cousin!

Klamath-Siskiyou Native Seeds. 2015, Aug. 28. Late season bloomer: Common madia (Madia elegans).

KQED San Francisco. 2021, Sept. 8. You can’t unsee the assassin bug’s dirty work [Video]. Deep Look. YouTube.

LoPresti, E., B. Krimmel, and I. Pearse. 2017, Dec. 20. Entrapped carrion increases indirect plant resistance and intra-guild predation on a sticky tarweed. Abstract. OIKOS.

Lowry, J.L. 2009, July 1. The scent of summer. Bay Nature.

Mauseth, J. 2012. Botany: An Introduction to Plant Biology (5th ed.). Jones & Bartlett Learning. Burlington, Massachusetts.

Peirce, P. 2012, Sept. 21. Daytime napper Madia elegans trying to survive. SFGate.

Prigge, B.A., and A.C. Gibson. 2013. Madia elegans. A Naturalist’s Flora of the Santa Monica Mountains and Simi Hills, California. Web version, hosted at Wildflowers of the Santa Monica Mountains National Recreation Area. United States Department of Interior, National Park Service.

Stevens, M., and B. Obrien. 2003, May 21. Common madia Madia elegans D.Don ex Lindl. Plant Guide. United States Department of Agriculture, Natural Resources Conservation Service, National Plant Data Center and Rancho Santa Ana Botanic Garden, Claremont, California.

Williams, G. W. 2000. Early fire use in Oregon. Fire Management Today 60(3): 13-20.

Williams, G. W. 2003. References on the American Indian use of fire in ecosytems. Intertribal Timber Council.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Charters, M.L. 2015. California Plant Names: Latin and Greek Meaning 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.

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.

Native American Ethnobotany DB.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.