Yellow Starthistle Centaurea solstitialis L.

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Yellow Starthistle Centaurea solstitialis L.

• Common Names
• Golden star thistle, St. Barnabys thistle,
  yellow centaury, yellow cockspur and geeldissel

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What is Yellow Star Thistle?

• Yellow star thistle is an annual dicot with
  several erect branches that each contain a
  flowering head covered in thorny bracts.

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What is Yellow Star Thistle?

• Classification
• Kingdom Plantae Plants
• Subkingdom Tracheobionta Vascular plants
• Superdivision Spermatophyta Seed plants
• Division Magnoliophyta Flowering
  plants
• Class Magnoliopsida Dicotyledons
  
• Subclass Asteridae
• Order Asterales
• Family Asteraceae
  Aster (Sunflower) family
• Genus Centaurea L.
  knapweed
• Species Centaurea
  solstitialis L. yellow star-thistle

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Why is it Bad?

• The thorns on the head of the star thistle
  interfere with livestock grazing, recreation and
  wildlife management
• Yellow Star Thistle is also toxic to horses and
  can cause a potentially fatal disorder called
  chewing disease.
• Reduction of biodiversity due to displacement of
  native vegetation.
• Linda M. Wilson, Cynthia Jette, John Connett,
  Joseph P. McCaffrey. 2003. Biology and Biological
  Control of Yellow Starthistle. USDA Forest
  Service FHTET-1998-17 2nd Ed.

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Why is it Bad?

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Life History- Yellow Star Thistle

• Seed germination in the fall and development into
  overwintering rosettes.
• Rapid growth in late spring with stalk growth
  each with a flower bud.
• Yellow flowers bloom in early summer.
• By late summer the plant begins to dry.

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Life History- Yellow Star Thistle

• Seeds dipersed by wind, water or by clinging to
  fur or clothing during the late summer and early
  fall.
• Yellow star thistle continues to dry over winter
  and eventually loses its thorny bracts and dies.

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Native Land U.S. Introduction

• Yellow star thistle is native to Eurasia.
• Introduced to the U.S. in the 1800s through
  accidentally contaminated seeds.

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U.S. Distribution
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States where C. solstitialis is Listed as Invasive

• California, Idaho, Oregon, Utah, Washington,
  Arizona, Colorado, Montana, New Mexico, Nevada,
  North Dakota and South Dakota.

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Control

• Grazing
• Cattle, sheep and goats will graze on yellow star
  thistle until it develops thorns.
• Toxic to horses.
• Low nutritional value
• Cattle with high yellow star thistle diet
  lose weight. (Callihan and others 1982)

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Control

• Mechanical
• Manual removal- Effective on small patches
  before seed production.
• Tillage- Can quickly reduce yellow star thistle
  seed bank, but can do the same to desirable
  species.
• Mowing- Too early or too late can increase the
  yellow star thistle infestation.
• Too early- Mowing can remove early competition
  by natives.
• Too late- Mowing can scatter yellow star
  thistle seeds.

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Control

• Fire Control
• Prescribed burns are not effective.
• Fire will kill the plant but not the seeds and
  may stimulate seed growth
• Yellow star thistle thrives in areas with
  increased sunlight, soil surface, bare soil and
  decreased competition.

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Control

• Chemical
• Picloram is the most widely used in the western
  states.
• Not registered for use in California.
• Clopyralid is effective for control and least
  damaging to grasses.

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Control

• Chemical cont.
• Picloram resistance observed in yellow star
  thistle in frequently treated areas.
• Most effective when used on early growth.
• It is important to incorporate other modes of
  control.

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Biological Control- Weevils

• Bangasternus orientalis (seedhead weevil)-
  attacks the early bud stages
• Eustenopus villosus (hairy weevil)- Feeds on mid-
  stage buds and lays eggs in late-stage buds
• Larinus curtus (flower weevil)- Lays eggs in open
  flowers

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Case Study

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Biological Control- Flies

• Chaetorellia australis (peacock fly)and C.
  succinea (false peacock fly)- feeds on seedheads
• Urophora siruneseva(seadhead fly)- Forms galls in
  seedheads
• C. Succinea- accidentally released and not
  approved due to damage to safflower.

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Costs

• Ecological
• Dense populations of yellow star thistle use
  deep soil water earlier than natives.
• Natives can experience drought conditions in
  years with normal rainfall.
• (Benefield et. al., 2001) and (Gerlach et. al.,
  1998.)

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Costs

• Economic
• Interference with
• Livestock grazing
• Forage harvesting procedures
• Lower yield and forage quality

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Is it Good?

• Honey
• An important honey source in California and
  other western states
• Medicine
• Used in Turkish folk medicine for ulcer
  treatment.
• Lab tests of flower extract show significant
  antiulcerogenic activity in rats.

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Questions

• ?

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References

• Benefield, Carri B. DiTomaso, Joseph M. Kyser,
  Guy B. 1998. Impacts of yellow starthistle
  density on the soil moisture profile and
  rangeland management. Proceedings, Western
  Society of Weed Science. 51 66. 40408
• Bussan, Alvin J. Dyer, William E. 1999.
  Herbicides and rangeland. In Sheley, Roger L.
  Petroff, Janet K., eds. Biology and management of
  noxious rangeland weeds. Corvallis, OR Oregon
  State University Press 116-132. 35716
• Carlson, John E. Willis, David B. Michalson,
  Edgar L. Callihan, Robert H. 1990. Yellow
  starthistle in north-central Idaho a survey of
  farmers' and ranchers' behavior and attitudes.
  Bulletin No. 712. Moscow, ID University of
  Idaho, College of Agriculture, Agricultural
  Experiment Station. 11 p. 40405
• DiTomaso, Joe. 2001. Element stewardship
  abstract Centaurea solstitialis L. In Weeds on
  the web The Nature Conservancy wildland invasive
  species program, Online. Available
  http//tncweeds.ucdavis.edu/esadocs/documnts/cents
  ols.html 2001, December 19. 40416
• Gerlach, John Dyer, Andrew Rice, Kevin. 1998.
  Grassland and foothill woodland ecosystems of the
  Central Valley. Fremontia. 26(4) 39-43. 40400

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References

• Hastings, Marla S. DiTomaso, Joseph M. 1996.
  Fire controls yellow starthistle in California
  grasslands. Restoration and Management Notes.
  14(2) 124-128. 40398
• Linda M. Wilson, Cynthia Jette, John Connett,
  Joseph P. McCaffrey. 2003. Biology and Biological
  Control of Yellow Starthistle. USDA Forest
  Service FHTET-1998-17 2nd Ed.
• Maddox, Donald M. Mayfield, Aubrey Poritz, Noah
  H. 1985. Distribution of yellow starthistle
  (Centaurea solstitialis) and Russian knapweed
  (Centaurea repens). Weed Science. 33 315-327.
  23467
• Yesilada, Erdem Sezik, Ekrem Fujita, Tetsuro
  and others. 1993. Screening of some Turkish
  medicinal plants for their antiulcerogenic
  activities. Phytotherapy Research. 7(3) 263-265.
  28718
• Zouhar, Kris. 2002. Centaurea solstitialis. In
  Fire Effects Information System, Online. U.S.
  Department of Agriculture, Forest Service, Rocky
  Mountain Research Station, Fire Sciences
  Laboratory (Producer). Available
  http//www.fs.fed.us/database/feis/ 2008,
  December 8.