Phacelia tanacetifolia

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Phacelia tanacetifolia
Phacelia tanacetifolia 2 2003-04-07.jpg
Scientific classification e
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Boraginales
Family: Boraginaceae
Genus: Phacelia
Species: P. tanacetifolia
Binomial name
Phacelia tanacetifolia
Phacelia tanacetifolia - MHNT

Phacelia tanacetifolia is a species of phacelia known by the common names lacy phacelia, blue tansy or purple tansy.


Phacelia is derived from Greek and means 'bundle', in reference to the clustered flowers, while tanacetifolia means 'with leaves resembling those of Tanacetum.'[1]


This is an annual herb which grows erect to a maximum height near 100 centimeters. The wild form is glandular and coated in stiff hairs. The leaves are mostly divided into smaller leaflets deeply and intricately cut into toothed lobes, giving them a lacy appearance. The very hairy inflorescence is a one-sided curving or coiling cyme of bell-shaped flowers in shades of blue and lavender. Each flower is just under a centimeter long and has protruding whiskery stamens.

The seeds are "negatively photoblastic", or photodormant, and will only germinate in darkness.[2]

Range and uses[edit]

Beneficial insects[edit]

It was originally native to the Southwestern United States and northern Mexico,[3] but it is now used in many places in agriculture as a cover crop, a bee plant, an attractant for other beneficial insects, as a green manure [4] and an ornamental plant. It is planted in vineyards and alongside crop fields, where it is valued for its long, coiling inflorescences of nectar-rich flowers which open in sequence, giving a long flowering period.[5] It is a good insectary plant, attracting pollinators such as honey bees.[5]

Biological pest control[edit]

It is also attractive to hoverflies (family Syrphidae), which are useful as biological pest control agents because they eat aphids and other pests.[6]


  1. ^ Gledhill, David (2008). "The Names of Plants". Cambridge University Press. ISBN 9780521866453 (hardback), ISBN 9780521685535 (paperback). pp 229, 370
  2. ^ Serrato-Valenti, S., et al. (1998). A histological and structural study of Phacelia tanacetifolia endosperm in developing, mature, and germinating seed. International Journal of Plant Sciences 159:5 753-61.
  3. ^ "Phacelia tanacetifolia". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 12 January 2018. 
  4. ^ "Green Manure". RHS. Retrieved 15 October 2015. 
  5. ^ a b Phacelia tanacetifolia: A brief overview of a potentially useful insectary plant and cover crop. Small Farm Fact Sheet.
  6. ^ Hickman, J. M. & W. D. Wratten. (1996). Use of Phacelia tanacetifolia strips to enhance biological control of aphids by hoverfly larvae in cereal fields. Journal of Economic Entomology 89:4 832-40.

External links[edit]