Protea intonsa explained

Protea intonsa, also known as the tufted sugarbush,[1] [2] [3] is a species of flowering plant in the family Proteaceae,[1] [2] [4] endemic to South Africa,[1] [4] where it is distributed from the eastern Swartberg and Kammanassie Mountains to the Baviaanskloof mountains.[1] [3] In Afrikaans, it is known as klossie-suikerbos.

Taxonomy

Protea intonsa has only been known to exist for half a century or so, it was first described as new to science by the South African botanist John Patrick Rourke in 1971.[5] He had first collected the species in 1967 in the Oudtshoorn Local Municipality on the rocky southeastern slopes of the Mannetjiesberg at 4800feet elevation (collector #860).[5]

An isotype of Rourke's original collection is housed at the herbarium at Kew.[5]

P. intonsa was classified in Protea section Crinitae by Tony Rebelo in 1995, what he calls the "eastern ground sugarbushes", along with P. foliosa, P. montana and P. vogtsiae.[6]

Description

This plant is a small, densely branched shrub up to 30cm (10inches) tall.[3] It is acaulescent, the shrubs having the appearance of low tufts 1feet-2feetft (-ft) in diameter.[5] The stems (rhizomes) grow underground, and have a characteristically scaled bark.[6] It is a long-lived species.[1]

The leaves are linear, narrow and slightly glaucous.[5] [6]

The inflorescences are specialised structures called pseudanthia, also known simply as flower heads, containing hundred of reduced flowers, called florets. These inflorescences are surrounded by petal-like appendages known as 'involucral bracts'. These bracts are pale green or greenish white base colour, this being flushed with carmine. The margins of the bracts are a dull carmine, except for the apex, which is covered in a 7mm long, white-coloured beard of hairs.[5] It is a monoecious species, both sexes occur in each flower.[3] The blooms are produced in late spring,[2] between September and November.[3]

Similar species

Protea intonsa is similar to P. vogtsiae in section Crinitae, both being dwarf shrubs with subterranean stems, and has similar leaves to P. montana, which is a larger mat-forming plant with much-branched stems growing prostrate on the ground.[6]

Distribution

Protea intonsa is endemic to the southwestern part of the Cape Region of South Africa,[1] [4] where it is found in the south of the area where the Western Cape and Eastern Cape provinces meet.[1] It occurs in the eastern Swartberg, Kammanassie and Baviaanskloof mountains.[1] [3] It is found on the Mannetjiesberg, the highest mountain in the Kammanassie Mountains,[2] [5] where it occurs frequently, in patches.[5] The species is often spatially distributed as isolated populations of scattered plants.[3]

Ecology

Habitat

It grows on dry, exposed mountain slopes at altitudes between 1,000 and 1,600 metres.[1] [3] It has only been found to occur in a fynbos habitat sometimes on high mountains, or in grassy fynbos. It is usually found on a substrate derived from sandstone, but near Kango in the Swartberge it occurs on conglomerates.[1]

Wildfires

According to one source, the wildfires which periodically move through the land in which the shrub grows destroy the adult plants, but the seeds can survive such an event,[3] whereas a more recent source states the plants survive fires by being able to re-sprout from underground stems.[1] The florets are pollinated by rodents. The seeds are retained in the old, dry, fire-resistant infructescence on the plant for two years, when they are finally released after fires the seeds are dispersed by the wind.[1] [3]

Conservation

Although the range is restricted to a relatively small area,[1] it is not threatened.[1] [3] The South African National Biodiversity Institute assessed the conservation status of the species for the Red List of South African Plants as 'least concern' in 2019, this assessment had first been given by the same organisation in 2009. It is not threatened by anything serious and is not in danger of extinction.[1]

A population is protected within the Kammanassie Nature Reserve.[2] [5]

Notes and References

  1. Web site: Rebelo . A.G. . Mtshali . H. . von Staden . L. . Tufted Sugarbush . Red List of South African Plants . version 2020.1 . 28 May 2019 . . 6 September 2020.
  2. Web site: Protea intonsa (Tufted protea) . Biodiversity Explorer . Iziko - Museums of South Africa . 6 September 2020.
  3. Web site: Eastern Ground Sugarbushes - Proteas . 11 March 1998 . Protea Atlas Project Website . 28 April 2020.
  4. Web site: Protea intonsa Rourke . 2017 . . . 6 September 2020.
  5. Web site: Specimen Details K000423683 . . Kew Herbarium Catalogue . Board of Trustees of the Royal Botanic Gardens, Kew . 6 September 2020.
  6. Peter . Craig I. . Dold . A. P. . Melidonis . Caitlin A. . Abraham . Susan . 2017 . Protea foliosa . . 65 . 42–48 . 4 September 2020.