Sparganium subglobosum
Common name
bur-reed, maru
Synonyms
Sparganium antipodum Graeb.
Family
Sparganiaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Herbs - Monocots
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
SPASUB
Chromosome number
2n = c.30
Current conservation status
The threat classification status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened | Qualifiers: DP, SO
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. North and South Islands. Present throughout the North Island though often scarce over large parts of this range. In the South Island very uncommon, known from Nelson, Marlborough, north Westland and from the Canterbury Plains. Also in Australia.
Habitat
Coastal to lowland (up to 400 m a.s.l.). Usually an emergent in shallow water, often on the margins of ponds, lakes and slow flowing streams. Also found in fens, and within the lagg zone of acidic bog systems. Usually preferring open sites, though sometimes found under Willows (Salix L. spp.) in moderately heavy shade.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland).
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Features
Glabrous, summer-green, rhizomatous, perennial herb of aquatic or fertile swamps. Rhizomes ascending, long and slender. Stems usually partially submerged in water, silt, mud or peat. Plants at flowering up to 1 m tall. Leaves most arising from base, somewhat spongy to firmly fleshy; 0.3-1 m tall, up to 10 mm wide, more or less erect; sheathing base channelled; lamina dark green, green to yellow green, linear to narrow linear, deltoid to subrhomboid in cross-section, longitudinal nerves distinct; incomplete cross walls occasionally evident apex obtuse to subacute. Peduncle up to 2 mm diameter, usually shorted than leaves; lower bracts foliaceous, long, often with basal third to one half clasping peduncle. Inflorescence simple or sparingly branched; main axis bearing up to 20 globose capitula; lower 1-6 female, rest male; lateral axis often bearing only male capitula, sometimes with up to 2 female capitula below; capitula sessile and either strictly axillary or without bracts. Flowers white. Male capitula up to 15 mm diameter, flowers numerous; stamens 3 mm long, filaments much > perianth; anthers conspicuous, white, oblong. basifixed, up to 3 times as long as broad. Female capitula to 18 mm diameter, flowers up to 60; perianth scales 4-8, the inner ones smaller; ovary 4 mm long, sessile, narrowly fusiform, unilocular, ovule solitary, pendulous; style short; stigma oval, c.1/2 style-length. Fruit 6 x 3 mm, dry, indehiscent, externally hard, internal spongy; dark green to yellow-green, sessile, obovoid, style base forming a hard, prolonged beak.
Similar taxa
None. The summer-green, soft, bright to dark green, linear leaves which are distinctly deltoid to subrhomboid in cross-section; and the simple to few-branched inflorescence bearing distinctive globose, many-flowered capitula, and/or globose spiky fruits are highly diagnostic of this species
Flowering
September - April
Flower colours
White
Fruiting
November - May
Propagation technique
Easily grown from fresh seed and by division of established plants. Best grown in full sun with the roost permanently submerged. An excellent plant for a shallow pond or slow flowing stream. However, can be grown in partially submerged pots.
Etymology
subglobosum: From the Latin sub- ‘somewhat’ or ‘not quite’ and globosus ‘globe shaped’, i.e. nearly spherical
Where To Buy
Not commercially available
Attribution
Description adapted from Moore and Edgar (1970).
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.