demersum Images: Click on each image to see a larger version and details of the record
Photo: Helen Pickering
Off Bovu Island, Zambezi River
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Ceratophyllum oxyacanthum Cham. Ceratophyllum tuberculatum Cham.
Rigid hornwort (English)
Description: Submerged aquatic herb. Stems up to 3m long and 2 mm in diameter, longitudinally grooved. Leaves in whorls of 7-11, 8-40 mm long, filiform, forked 1-2(3) times; margin with spine-tipped teeth, particularly in the apical segments. Flowers axillary, unisexual on the same plant; male flowers in many 1-3-flowered clusters per branch; female flowers solitary, few per branch. Fruit ovoid, ellipsoid to obovoid with an apical spine and 2 prominent basal spines, and raised dark spots on the surface.
Derivation of specific name:
Habitat: Occurring an most types of permanent fresh water, even in brackish estuaries, often forming thick mats just below the surface.
Altitude range: (metres)
Up to 1600 m
Worldwide distribution: Subcosmopolitan in temperate and tropical regions.
Growth form(s): Aquatic.
Red data list status:
Insects (whose larvae eat this species):
Display spot characters for this species
Content last updated: Saturday 23 January 2010
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Other sources of information about Ceratophyllum demersum: Our websites: Flora of Mozambique
Ceratophyllum demersum Flora of Zambia
Ceratophyllum demersum External websites: African Plant Database
Ceratophyllum demersum Biodiversity Explorer
(Biodiversity of southern Africa):
Ceratophyllum demersum EOL
(Encyclopedia of Life):
Ceratophyllum demersum ePIC
(electronic Plant Information Center):
Ceratophyllum demersum Flora Zambesiaca
Ceratophyllum demersum Google
(Germplasm Resources Information Network) taxonomy for plants report for
Ceratophyllum demersum IPNI
(International Plant Names Index):
Ceratophyllum demersum JSTOR Plant Science
Ceratophyllum demersum Kew Herbarium catalogue
Ceratophyllum demersum Tropicos
Ceratophyllum demersum West African Plants database
Copyright: Mark Hyde, Bart Wursten and Petra Ballings, 2002-13
Hyde, M.A., Wursten, B.T. & Ballings, P.
Flora of Zimbabwe: Species information: Ceratophyllum demersum var. demersum.
http://www.zimbabweflora.co.zw/speciesdata/species.php?species_id=123480, retrieved 6 December 2013
Site software last modified: 13 October 2013 5:45am (GMT +2)