The New Zealand Plant Conservation Network

Species

Sparganium subglobosum

Etymology

subglobosum: From the Latin sub- 'somewhat' or 'not quite' and globosus 'globe shaped', i.e. nearly spherical

Common Name(s)

burr-reed, maru

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Sparganium subglobosum Morong

Family

Sparganiaceae

Flora Category

Vascular - Native

NVS Species Code

SPASUB

Structural Class

Monocotyledonous Herbs

Synonyms

Sparganium antipodum Graeb.

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.

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.

Threats

Not Threatened

Chromosome No.

2n = c.30

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 11 Aug 2014