Common Name: Weather Prophet

General Information

Dimorphotheca pluvialis is an annual plant growing about 40cm tall. The flowers of this sun loving daisy only open with the warmth of the sun from about 10 o’clock in morning to 4 o’clock in the afternoon. As the sun moves across the sky their flowers follow, always facing the sun[].
A very ornamental plant, it is often grown as summer bedding in temperate areas[]. The plant is being investigated in several maritime countries of Europe as a possible source of oil for industrial uses[].

Known Hazards

None known

Botanical References

Range

Southern Africa - South Africa, Namibia.

Habitat

Not known

Properties

Other Uses Rating
Habit	Annual
Height	0.40 m
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental

Cultivation Details

Plants are not frost-resistant and are grown as summer annuals in temperate zones[].
Prefers a dry, sunny position in a well drained soil rich in organic matter[]. Prefers a sandy, dry to medium moisture, well-drained soil in full sun[]. Tolerates drought and hot summers, but dislikes high humidity[].
Yields in field trials range from 0.5 - 1.5 t/ha, potential maximum yields are 2 - 2.5 t/ha[].
The seeds of this plant are interesting in that two different forms are produced[]. The ones usually sown are flat, papery and fly away easily in the wind. They are formed in the centre of the flower by the disk florets[]. The outer ray florets form seeds which looks like little thorns with thick coats[]. Under favourable conditions the papery seed of the disk florets germinate in abundance, while the seeds of the ray florets have delayed germination to protect the species against unpredictable conditions in their arid environment[].
A very ornamental plant, often grown as summer bedding[].

Edible Uses

None known

Medicinal

None known

Other Uses

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 (such as 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[].

Propagation

Seed - for the earliest crops, sow in pots in early spring in a greenhouse using a freely-draining potting compost[]. Seed takes about 3 weeks to germinate at 16°c[]. Be careful not to overwater at any time since the young plants are prone to damping off[]. Prick out the seedlings into individual pots as soon as the plants are large enough to handle and plant out in their permanent positions as soon as possible after the last expected frosts.
Seed can also be sown in situ in late spring[].