Family: Compositae
Genus: Dimorphotheca
Species: pluvialis
(i) General background on the plant
A herbaceous profusely branching annual species with narrow, dark green, leathery leaves. Height does not exceed about 30cm. The plant is native to South West Africa and is sometimes known as Cape Marigold. The flower head is borne at the end of the branches and has two types of florets - hermaphrodite disc florets and female-fertile / male-sterile ray florets. The ray florets have one large white petal which is often coloured purple at the base giving the appearance of a ring in the inflorescence. Flowering may continue for 3 months or more. The seeds are achenes and the two types of florets produce different seed types, rod-like and winged, the winged type being in the majority. When ripe the seeds are exposed and become creamy-brown when ripe, they then fall to the ground.
The plant is often grown in parks and gardens as an ornamental.
(ii) Details of quality characteristics
The seeds contain 60 - 65% dimorphecolic acid (d9-hydroxy,t10,t12-octadecadienoic acid)(the winged seeds contain a higher proportion of the oil). This is an unusually linked hydroxy fatty acid in that it has two conjugated double bonds. The structure of the fatty acid provides it with unique properties that are totally different from other known hydroxy fatty acids (eg ricinoleic and lesquerolic). Its structure also makes it much more highly reactive than many other fatty acids and therefore potentially suited to a wide range of industrial products, for example in the manufacture of urethane resins, paints, varnishes, lubricants and cosmetics. The enhanced reactivity of dimorphecolic acid necessitates great care in extraction and processing to minimise undesirable reactions.
(iii) Current production and yields
Yields in field trials range from 0.5 - 1.5 t/ha, potential maximum yields are 2 - 2.5 t/ha
(iv) Constraints upon production
Rain Daisy is well suited to the maritime climate of northern and western Europe but is frost sensitive.
Agronomic requirements are are little known as yet. Competition with weeds prior to canopy cover is weak and as yet there is no information available on herbicide useage. Timing is difficult because flowering, and therefore seed maturation, is asynchronous. Seed retention is also poor.
(v) Markets and market potential
Suitable for a wide range of applications such as surface coatings, surfactants, plastic foams or as additives in plastics.
(vi) Other information
Dimorphotheca pluvialis: A New Source of Hydroxy Fatty Acid
The plant is grown as an annual and sown in April to a high population density - up to 100 plants per m2 in narrow rows. It flowers in July and can be harvested in August.
Breeding and development work are being undertaken in several European countries, in particular the Netherlands.
(vii) Contacts
See the following pages in the NF-2000 Database
Rain daisy (Dimorphotheca pluvialis)
AGRE-0046 - Vegetable Oil for Innovation in Chemical Industries VOICI
Crops for Paints/Coatings/Plastics
(viii) References
Smith, N.O., Maclean, I., Miller, F.A. and Carruthers, S.P. (1997). Crops for energy and industry. Office for Official Publications of the European Communities.