Biodiversity & Conservation

Foxtail stonewort - Lamprothamnium papulosum

Lamprothamnium papulosum

Image Steve Trewhella - Lamprothamnium papulosum in the Fleet. Image width ca XX cm.
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Distribution map

Lamprothamnium papulosum recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

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  • WC_Act_1981
  • UK_BAP
Taxonomy icon Taxonomy Taxon English term
Phylum Chlorophyta Green seaweeds and stoneworts
Class Charophyceae
Authority (J. Groves, 1916)
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Found in Dorset (The Fleet), Fort Gilkicker Moat (Hampshire), Harbour Farm Lagoons, Bembridge (Isle of Wight), Great Deep (West Sussex) and in 9 saline lagoons in the Outer Hebrides. Extinct populations recorded from Dorset and the Isle of White.
Habitat information icon Habitat information Found in fairly still, brackish, nutrient-poor water on sand, gravel, small pebbles and silty substrata. Lamprothamnium papulosum usually grows in water of fluctuating salinity less than 2 m deep, and is often associated with Ruppia maritima or Ruppia cirrhosa communities. This stonewort prefers water of salinities of between 8-28 psu, or 6 gl-1 to 31 gl-1 and total phosphorus lower than 103 g l-. Variation in salinity appears to be important, with >15 gl-1 (24-28 ppt) being optimal for vegetative growth, with a salinity range of > 4 gl-1. Lamprothamnium papulosum has also been recorded from hypersaline conditions in Spain (Jonkers et al., 2003) and Australia (Davis & Lipkin, 1986).
Some disturbance by livestock/animals may benefit Lamprothamnium papulosum by reducing competitive vascular plants. Habitats for Lamprothamnium papulosum may be transient, due to salinity fluctuations or desiccation in the absence of rainfall/freshwater inputs. Lamprothamnium papulosum is able to quickly recolonize from the spore bank when suitable conditions reoccur. However the saline lagoons habitat itself is rare and threatened.
Text page icon Description Lamprothamnium papulosum has slender pale green stems, sometimes with yellowish tips, reaching up to 40 cm in height which are anchored in the sediment by fine rhizoids. The main stem gives rise to whorls of simple, equal sized branchlets. The stem of each branchlet bears whorls of slender spines at regular intervals and branchlets are simple either unencrusted or slightly encrusted. The whorls of branchlets become closer together at the top of the stems to give a bushy, 'foxtail' appearance. Lamprothamnium papulosum grows either solitarily or in clumps. Identification of Lamprothamnium papulosum may not be verifiable based on morphological/anatomical information, therefore ideally a small sample should be sent to the National Stonewort Recorder (Nick Stewart) for expert identification.
Identifying features
  • Thin, upright stems up to 40 cm in height, anchored in the sediment by rhizoids.
  • Whorls of simple spine-like leaves at regular intervals.
  • Whorls equally spaced along the stem, becoming contracted and closer together at the top of the stem, giving a bushy 'foxtail' appearance.
  • Branchlets are simple and covered in whorls of fine spines.
  • Due to morphological plasticity, expert confirmation of identification is adviced.
Additional information icon Additional information Lamprothamnium papulosum appears to be declining throughout its range and is vulnerable to habitat destruction.

This review can be cited as follows:

Catherine Wilding & Penny Avant 2004. Lamprothamnium papulosum. Foxtail stonewort. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 09/02/2010]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=3629>