''Prionium serratum'', the palmiet, is a robust, evergreen, semiaquatic,
rhizomatous
In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...
growing to in height. It is the only species in the genus ''Prionium'', and is
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
(
Cape Province
The Province of the Cape of Good Hope (), commonly referred to as the Cape Province () and colloquially as The Cape (), was a province in the Union of South Africa and subsequently the Republic of South Africa. It encompassed the old Cape Co ...
and
KwaZulu-Natal
KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...
).
[Kew World Checklist of Selected Plant Families]
/ref> Some authors have separated ''Prionium'' from the Thurniaceae, putting it instead in its own family, the Prioniaceae.
Description
The stem of ''P. serratum'' is up to in diameter and covered with the black, fibrous bases of old spirally arranged leaves, four-ranked or tristichous, as in the closely related family Juncaceae, a family in which it was previously placed - it also has close affinities with the bergpalmiet (''Tetraria thermalis'') in the Cyperaceae. The strap-like lanceolate leaves are rigid, with a high silica content, narrow, leathery, grey-green, and with toothed margins. The small, brown flowers are on a branched inflorescence about 1 m in length. Plants are hermaphroditic and pollination is anemophilous. The fruit is a dry dehiscent triangular capsule, with three seed chambers and arillate seeds which are hispid (with sclerenchymatous fibres) and winged. The net-like, black fibrous, reticulate leaf sheaths are often found on beaches near rivers with colonies of palmiet (see Gallery). New flower shoots are cooked as vegetables.
Taxonomy and distribution
''P. serratum'' is one of only four species in the family Thurniaceae and the only member of the family native to southern Africa. This species has a disjunct distribution along the southern and south-eastern seaboard from the Western Cape to KwaZulu-Natal on sandstone Stratum, substrates, growing in dense mats in marshy areas, and in and along streams and rivers. Palmiet wetlands are ecosystems that greatly reduce the erosive damage done by floodwater. When palmiet is removed, streams may become choked by sediment and banks eroded by unchecked floodwater.
''Prionium'' is from the Greek for sawblade, while ''serratum'' is Latin for toothed.PlantZAfrica.com
/ref> The name ' was used by Jan van Riebeeck for this plant, doubtless because of its close resemblance to Chamaerops humilis, palmito and the Sabal, palmettos, and it was first noted by the Swedish botanist Carl Peter Thunberg in about 1772. The name evolved into wilde palmiet and then palmiet. Several rivers in the Western Cape have been named Palmiet River for this species growing along their courses - two of the larger ones are the Palmiet River mouthing between Betty's Bay and Kleinmond, and one having its source just west of Formosa Peak and eventually joining the Keurbooms River.
Gallery
Prionium serratum11.jpg
Prionium serratum.jpg,
Prionium serratum06.jpg,
Prionium serratum01a.jpg,
Prionium serratum04.jpg,
References
External links
Image of flowersFibrous tissuePalmiet River
{{Taxonbar, from=Q3019520
Thurniaceae
Aquatic plants
Monotypic Poales genera