Protea (
Sunset Western Garden Book, 1995:606–607
About 92% of the species occur only in the Cape Floristic Region, a narrow belt of mountainous coastal land from Clanwilliam to Grahamstown, South Africa. Most protea species are found south of the Limpopo River. Protea madiensis grows in Afromontane enclaves across tropical Africa, from Guinea to Sudan, Mozambique, and Angola.[ Protea madiensis Oliv. Plants of the World Online. Retrieved 27 September 2023].] Protea afra ranges from the Cape region to Uganda and Kenya, including in the chaparral zone of Mount Kenya National Park. The extraordinary richness and diversity of species characteristic of the Cape flora are thought to be caused in part by the diverse landscape, where populations can become isolated from each other and in time develop into separate species.
Etymology
The genus
Protea was named in 1735 by
Carl Linnaeus when he was examining male and female plants of a species now known as
Leucadendron argenteum which are very different from each other; he misunderstood them to be two different species, and he compared those forms to the ability of Greek god
Proteus who could change his form at will.
Linnaeus's genus was formed by merging several genera previously published by
Herman Boerhaave, although precisely which of Boerhaave's genera were included in Linnaeus's
Protea varied with each of Linnaeus's publications.
Taxonomy
The family
Proteaceae to which
Protea species belong is an ancient one among
angiosperms. Evidence from pollen fossils suggests Proteaceae ancestors grew in
Gondwana, in the
Upper Cretaceous, 75–80 million years ago.
The Proteaceae are divided into two subfamilies: the
Proteoideae, best represented in southern Africa, and the
Grevillea, concentrated in Australia and South America and the other smaller segments of Gondwana that are now part of eastern Asia. Africa shares only one genus with
Madagascar, whereas
South America and Australia share many common genera – this indicates they separated from Africa before they separated from each other.
Description
Proteas usually flower during spring. Protea flowers have large
perianth made of small florets packed on a woody receptacle, each floret is reddish or pinkish in color and measures between 28.4 and 53.8 millimeters. The
carpel in the flower's center is cream colored.
The ovary is protected by the receptacle, and thus is not seen when looking at the flower, but the
anthers are present at the top of the flower, which can then easily transfer the pollen to the vectors.
Proteas are pollinated by birds, insects, and wind. All the florets open big enough for small and medium beetles to land and feed on their nectar before flying to other heads pollinating them in the process.
Genetics
The common Proteaceae plants, e.g.
Protea,
Leucospermum, and
Leucadendron are diploid organisms, thus they can freely hybridize with closely related species to form new cultivars. Unusually, not all the genera within the family Proteaceae can hybridize freely; for example,
Leucadendron species cannot be crossed with
Leucospermum species because of the difference in their haploid chromosome number (13 and 12, respectively). This genetic incompatibility results in pollinated flowers that yield either no fruit, or seedless fruit, as the resulting plant embryos, from the incompatible pollen and ovum, fail to develop.
Botanical history
Proteas attracted the attention of botanists visiting the Cape of Good Hope in the 17th century. Many species were introduced to Europe in the 18th century, enjoying a unique popularity at the time amongst botanists.
Cultivation
Proteas are currently cultivated in over 20 countries. Cultivation is restricted to Mediterranean and
Subtropics.
Three categories of traits have to be considered before developing a new cultivar. The yield or production capacity of the cultivar must be considered. The ease of handling and packaging of the cut stems and the last category is to consider the perceived market value of the cultivar.
The cultivation of a
Protea plant is time-consuming, so good planning when developing the cross combinations and goals are of great importance of the breeding programme.
Classification
Within the huge family
Proteaceae, they are a member of the subfamily Proteoideae, which has Southern African and Australian members.
Species
(listed by section: a 'section' has a name in two parts, consisting of the genus name and an epithet).
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Protea sect. Leiocephalae
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Protea sect. Paludosae
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Protea sect. Patentiflorae
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Protea sect. Lasiocephalae
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Protea gaguedi (African sugarbush)
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Protea welwitschii (dwarf savanna sugarbush)
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Protea sect. Cristatae
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Protea asymmetrica (Inyanga sugarbush)
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Protea wentzeliana (Wentzel's sugarbush)
-
Protea sect. Protea
-
Protea cynaroides (king protea)
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Protea sect. Paracynaroides
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Protea cryophila (snow protea)
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Protea pruinosa (frosted sugarbush)
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Protea scabriuscula (hoary sugarbush)
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Protea scolopendriifolia (Hart's tongue-fern sugarbush)
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Protea sect. Ligulatae
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Protea burchellii (Burchell's sugarbush)
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Protea compacta (Bot River sugarbush)
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Protea eximia (broad-leaf sugarbush)
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Protea longifolia (long-leaf sugarbush)
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Protea obtusifolia (limestone sugarbush)
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Protea pudens (bashful sugarbush)
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Protea roupelliae (silver sugarbush)
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Protea susannae (stink-leaf sugarbush)
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Protea sect. Melliferae
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Protea sect. Speciosae
-
Protea coronata (green sugarbush)
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Protea grandiceps (red sugarbush)
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Protea holosericea (saw-edge sugarbush)
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Protea laurifolia (gray-leaf sugarbush)
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Protea lepidocarpodendron (black-beard sugarbush)
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Protea lorifolia (strap-leaf sugarbush)
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Protea magnifica (queen sugarbush)
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Protea neriifolia (oleander-leaf protea, narrow-leaf sugarbush)
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Protea speciosa (brown-beard sugarbush)
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Protea stokoei (pink sugarbush)
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Protea sect. Exsertae
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Protea sect. Microgeantae
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Protea sect. Crinitae
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Protea sect. Pinifolia
-
Protea acuminata (blackrim sugarbush)
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Protea canaliculata (groove-leaf sugarbush)
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Protea nana (mountain-rose sugarbush)
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Protea pityphylla (Ceres sugarbush)
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Protea scolymocephala (thistle sugarbush)
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Protea witzenbergiana (swan sugarbush)
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Protea sect. Craterifolia
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Protea sect. Obvallatae
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Protea caespitosa (bishop sugarbush)
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Protea sect. Subacaules
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Protea aspera (rough-leaf sugarbush)
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Protea denticulata (tooth-leaf sugarbush)
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Protea lorea (thong-leaf sugarbush)
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Protea piscina (Visgat sugarbush)
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Protea restionifolia (reed-leaf sugarbush)
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Protea scabra (sandpaper-leaf sugarbush)
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Protea scorzonerifolia (channel-leaf sugarbush)
External links
