T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Phacelia tanacetifolia (Lacy phacelia)

Kingdom: Plantae
Clade: Tracheophyta
Phylum: Magnoliophyta
Class: Magnoliopsida
Family: Boraginaceae
Genus: Phacelia
Species: P. tanacetifolia
Binomial name: Phacelia tanacetifolia
Common names:  Lacy phacelia, Purple tansy, Blue tansy 

Phacelia tanacetifolia is annual herb native to the South-western United States and northern Mexico. It is related to borage (Borago officinalis).
Though not a problem plant it has escaped in certain areas in New Zealand.

Phacelia tanacetifolia is a beneficial plant which 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 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. It is a good insectary plant, attracting pollinators such as honey bees. It is often used as a companion plant alongside cucumber, tomato, cabbage, kales and broccoli.

It grows erect to a maximum height near 100 centimetres. The stems and leaves are coated in stiff hairs. The leaves are mostly divided into smaller leaflets deeply and intricately cut into toothed lobes, giving them a lacy appearance. 
Phacelia plants usually flower from spring right through summer. 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 centimetre long and has protruding whiskery stamens. The seeds are "negatively photoblastic", or photodormant, and will only germinate in darkness.

Phacelia tanacetifolia growing wild at the DOC camp, Lake Arapuni, Waikato