Protea eximia (Salisb. ex Knight) Fourc.
Common names: broad-leaf sugarbush, duchess protea, (Eng.); breëblaarsuikerbos (Afr.)
SA Tree No: 88.3
Protea eximia is a robust, easy-to-grow protea, presenting its showy, deep pink, purple-centred flower heads above greyish green foliage.
Protea eximia is a large, upright shrub, 2-5 m tall with a single main trunk and a rather lanky, sparsely branched growth habit. The leaves are greyish green to purplish green and are coated with a whitish bloom that can be rubbed off (glaucous). The leaves are leathery and hairless, narrowly to broadly egg-shaped, 60-100 x 30-65 mm. The base of the leaf, where it attaches to the petiole, is heart-shaped with a deep notch where the petiole is inserted (cordate), and in some plants the two rounded lobes at the base of the leaf are ear-shaped and project quite prominently (auriculate).
The flower heads are large, 100-140 mm long, and up to 120 mm across when fully opened. The outer surfaces of the floral bracts are covered in fine silky hairs (sericeous) and the margins are fringed with hairs (ciliate). The outer series of floral bracts (those lower down on the flower head) are usually greenish or yellowish white or white flushed with pink, with a brown edge. The inner series of floral bracts are long and spoon-shaped, and usually deep pink, although colour varies in wild populations from pink to orange-brown. When the flower head opens, there is a central dark purple ring in the centre.
This is because the tips of the long, narrow flowers massed in the centre of the flower head are covered in purple-black, velvety hairs. At first, no flowers are open and they are all massed together in the centre, so the purple colour is very pronounced. The flowers open from the outside inwards, and as they do so the perianth (with the purple hairs) collapses and separates from the central mass, so the purple ring becomes less pronounced and the colour more diffuse as the flowers open. The collapsed perianths are the thread-like structures that can be seen falling between the floral bracts, and they cause the older flower heads to look rather untidy.
Flowering time is mainly during spring to early summer (August to October) but flower heads are found on the bushes from midwinter until midsummer (June until December).
Protea eximia is easy to tell apart from other proteas by its cordate to auriculate, hairless leaves, spoon-shaped floral bracts and purple-centred flower head. It is most often confused with the hybrids Sylvia and Cardinal, which are hybrids between itself and P. susannae and they have inherited its purple-centred flower head but not its foliage.
Protea eximia is not threatened.
Distribution and habitat
Protea eximia is widespread throughout the mountains of the southern Cape, from the Keeromsberg near Worcester, along the Langeberg, Outeniqua and Tzitzikamma Mountains to Van Stadensberg near Port Elizabeth. It is also found on the Waboomsberg, Klein Swartberg, Rooiberg, Groot Swartberg, Kamanassie and Kouga Mountains and Strydomsberg. Within its distribution range, rainfall varies from 380 mm to 1000 mm per year. P. eximia occurs in dense stands on sandstone slopes, 200-1600 m above sea level. It is found growing in many different habitats, from dense well-watered fynbos at low altitudes, to sparse, arid fynbos on the high mountains where light frost and snowfalls occur during the winter months.
Derivation of name and historical aspects
The genus Protea was named by Linnaeus after the Greek god Proteus who could change his form at will, because the proteas are so different in form. The species name eximia is Latin and means distinguished, excellent or extraordinary - clearly this species made a good impression on Richard Salisbury who proposed the name.
Protea eximia was discovered by James Niven in the Swartberg, probably soon after 1805. He sent seed back to Lee and Kennedy's Nursery in London and the plants flowered in 1809. J.W. Mathews, curator of Kirstenbosch from 1913 until 1936, introduced P. eximia to the garden in 1914 from seed that he collected on the Swartberg Pass.
The Proteaceae is a family of ± 75 genera and ± 1350 species that occur in Africa, Madagascar, southeast Asia, Malaysia, the Pacific Islands, Australasia and South America. There are 16 genera and ± 360 species in southern Africa. The genus Protea contains ± 112 species, all of which occur only in Africa and 89 (79%) of them in southern Africa, mainly in the Western Cape.
Protea eximia is pollinated by the Sugarbird, Promerops cafer. Nectar is found at the base of each flower. To get to it, the Sugarbird has to push its head between the massed flowers. While doing this, pollen is rubbed of onto the bird's head. It then flies off to another bush and transfers its load of pollen to other flowers while it picks up some more.
The flower heads are also visited by many insects, including the protea beetle, which comes in search of pollen and nectar. The protea beetles are large and brush the pollen onto themselves as they move through the flower head and do effect some pollination, but are not the main pollinators. Sunbirds also feed on the nectar, but they do not effect pollination as they 'cheat' by sticking their beaks into the side of the flower heads straight to the base of the flowers, bypassing the pollen.
Fynbos is fire-adapted and plants have developed different strategies to survive fires, the main two being reseeding and resprouting. A reseeder is usually single-stemmed at ground level and the whole plant is killed by the fire, but it produces large numbers of seeds that are often stored on the bush during its lifetime and germinate en masse after a fire. A resprouter is usually multi-stemmed at ground level and although the above-ground parts of the plant are killed, it has a large underground rootstock, known as a lignotuber, which survives and sends out vigorous new growth soon after the fire. Protea eximia is a reseeder. It holds the previous year's seeds in the old flower heads, which are stored on the bush.
Protea eximia is good cut flower, with long-lasting flower heads and long stems, and is cultivated for the export market. There is a degree of variation within the species with different forms of it around. A very striking form that has been named is P. eximia 'Fiery Duchess' with blue-grey foliage and very deep reddish pink floral bracts. P. eximia is also the parent in a number of hybrids e.g. P. eximia x susannae 'Sylvia', P. eximia x susannae 'Cardinal' and P. compacta x eximia 'Pink Duke'.
Growing Protea eximia
Protea eximia is one of the easier proteas to cultivate as it tolerates quite a wide range of soils and conditions, as well as wind and light frost. Plant it in a sunny position, in well-drained soil where there is free air circulation. Water well throughout the year but particularly during autumn-winter-spring. Like other proteas it is a light feeder with a sensitive root system that is adapted to very nutrient-poor soils. It will not tolerate strong fertilizers and manures, but should be fed with well-rotted compost and if using chemical fertilizers, choose a slow-release one or apply very low doses.
Tip young plants regularly to encourage branching. Remove the spent flower heads immediately after flowering to encourage a more compact bush. Also, as it can be a bit lanky and sparsely branched, plant in close groups of three or five so the plants can support each other and achieve a more dense bush. It is a long-lived protea, and can reach 20 or 30 years and show no signs of senescence.
Grow Protea eximia in the fynbos garden, the coastal garden, the water-wise garden or in gardens with alkaline soils where most mountain proteas fail. It tolerates brief, light frosts and can therefore be grown successfully in Highveld gardens and should survive outdoors in Zone 9 (-7 to -1°C / 20 to 30°F). It can be grown in the shrubbery, towards the back of a mixed border, and produces a steady supply of cut flowers during winter to early summer.
Protea eximia can be propagated by seed or cuttings. Sow seed in autumn to early summer, in well-drained soil, lightly covered with clean sand or fine-milled bark and kept moist but not wet. Germination occurs after 3 weeks. Treating the seed with a fungicide increases the number of surviving seedlings. Transplant into individual containers as soon as the first pair of true leaves have developed. Seedlings grow rapidly and the first flowers can be expected in their second or third year.
Take semi-hardwood cuttings from the current season's growth, in autumn or spring. Remove the leaves from the basal third of the cutting, treat with a rooting hormone, and place in a well-drained rooting medium under intermittent mist with a bottom heat of 25°C.
Protea eximia leaves are prone to attack and disfigurement by leaf miners.
- Goldblatt, P. & Manning, J. 2000. Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9. National Botanical Institute, Pretoria & Missouri Botanical Garden, Missouri.
- Leistner, O.A. (ed.). 2000. Seed plants of southern Africa : families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Rebelo, A.G. (Tony). 2001. Proteas. A field guide to the proteas of southern Africa, edn 2. Fernwood Press, Cape Town.
- Rourke, J.P. 1982. The proteas of southern Africa. Centaur Publishers, Johannesburg.
- Vogts, M. 1982. South Africa's Proteaceae, know them and grow them. Struik, Cape Town.
Kirstenbosch National Botanical Garden
Plant Type: Shrub
SA Distribution: Eastern Cape, Western Cape
Soil type: Sandy
Flowering season: Spring, Early Summer, Winter
PH: Acid, Alkaline, Neutral
Flower colour: Purple, White, Pink
Aspect: Full Sun
Gardening skill: Easy