Protea Colour Survey
Protea flowerhead colour survey
Most South Africans will already know that Protea flowerheads come in either pink or white, but have you ever asked yourself "Why"? Unlike your garden-variety Hydrangeas, whose red or blue colour depends on soil pH, flowerhead colour in Protea species is genetically determined, just like the colour of your eyes. You or I may prefer one colour over another (hey, colour diversity is the spice of life), but what does it matter to a Protea whether its flowerheads are pink or white?
A research team from the University of Connecticut, USA, led by Dr Jane Carlson and collaborators at Kirstenbosch are teaming up with you to ask that very question: Does flowerhead colour affect how well Protea plants survive or reproduce in their natural environments? Why do we find both white and pink plants of the same species in some sites, but only one colour in others?
To explore how Protea flowerhead colour varies on the landscape scale, we’re asking for your help! We’re targeting the wide-spread Common Sugarbush Protea repens (see above), but we welcome flower colour data on any of the Proteas, most especially the larger, bird-pollinated species listed below.
What we’re asking for is this:
Anytime you’re near a patch of flowering Protea plants, take note of whether the outermost parts (the bracts) of the flowerheads are pale to white or pink.
Within a given area or population, do you see only plants with white/pale bracts, plants with pink bracts, or do you see both? (or if you some other colour, let us know!) Your ‘pink’ bracts can range from light peachy pink to bright pink or red, and the pink can cover the whole bract or be concentrated just on the base or tips. Once you get a sense of which colours are present, take some photos of representative plants and upload them onto iSpot as part of the Protea Colour Survey.
Please add the following information when uploading your observation to iSpot:
Under Description: note how many plants had pale or coloured flowerheads.
e.g.: 35% white, 65% pink OR
15 white plants, 5 pink plants.
Under Descriptive Tags, please insert “Protea Colour Survey”
The map above shows the dominant colour of Protea repens at some of the sites we’ve already visited, but it’s really a work in progress. We’d love your input!
Here's a bit of background: We began this project by looking at how pollinators and seed-eating insects respond to flowerhead colour using four Protea species. Our early findings suggest that sugarbirds and sunbirds don't care too much about flowerhead colour, but seed-eating insects do. In half of our study sites, insect larvae ate more seeds of the white plants, perhaps because pink pigment is associated with distasteful plant compounds. Better defense may come at a cost, however, since pink plants also had smaller, poorer-quality seeds (see Jane's research webpage for more details). We suspect that certain environmental conditions, possibly related to soil type, elevation or aridity, also may favor one colour type over the other, but this has not yet been fully investigated (and why we're asking for your help!) We will begin by using the information you provide on ispot, plus our own observations, to relate the dominant flowerhead colour for each species in a site to relevant soil and climate data extracted from GIS layers. We'll keep you updated as work progresses!
Look at the results of the Protea Colour Survey to date!
Priority species:
- Protea aurea subsp. aurea
- Protea aurea subsp. potbergensis
- Protea burchellii
- Protea compacta
- Protea cynaroides
- Protea lacticolor
- Protea laurifolia
- Protea lepidocarpodendron
- Protea longifolia
- Protea lorifolia
- Protea magnifica
- Protea mundii
- Protea neriifolia
- Protea obtusifolia
- Protea punctata
- Protea repens
- Protea speciosa
Latest observations