The New Zealand Plant Conservation Network

Species

Machaerina complanata

Etymology

complanata: Levelled or flattened

Common Name(s)

None Known

Current Conservation Status

2012 - Threatened - Nationally Vulnerable

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 - Threatened - Nationally Vulnerable
2004 - Range Restricted

Qualifiers

2012 - RF
2009 - RF

Authority

Machaerina complanata (Bergg.) Koyama

Family

Cyperaceae

Flora Category

Vascular - Native

NVS Species Code

MACCOM

Structural Class

Sedges

Synonyms

Cladium complanatum Bergg., Baumea complanata (Bergg.) Blake

Distribution

Endemic. Known only from the North Island, where it now occurs locally from Te Paki south to the Kaipara Harbour. It was also once present in the Waikato on the shores of Lake Waaihi, and there are recent subfossil deposits made by this species in peat bogs (now drained) at Papamoa and Te Puke (Bay of Plenty)

Habitat

Coastal to lowland (1-300 m a.s.l.). A species of open habitats which has been collected from estuaries (in salt marsh), consolidated dune swales (which are seasonally wet), freshwater lake and river margins, amongst gum land scrub, under regenerating kauri, from the margins of geothermally active springs and fumaroles, and from acidic peat bogs.

Features

Dark green, tufted and leafy sedge. Culms 05–0.9(-1.3) m tall, c.3 mm wide, smooth, ± compressed. Leaves ± = culms, 4–8 mm wide, flat, distichous, isobilateral equitant, striated, pale green, tip acute, margins glabrous Panicle 0.15–0.50 m long, narrow, erect from a long sheath with short lamina; branchlets flexible, fascicled from upper sheaths. Spikelets, c.5 mm 1ong, light red-brown, 2–3-flowered, 1–2 flowers fertile. Glumes 5–6, ovate, acuminate or acute, chartaceous, striped with brown, scabrid on back towards tip, margins minutely ciliate. Nut, including beak, c.4 × 2 mm, trigonous, red-brown, very shortly stipitate, narrowed above to a long, triquetrous, scabrid beak

Similar Taxa

Machaerina sinclairii is similar but has much wider (10-30(-40) mm) light green (rather than dark green) leaves, some what fluffy brown more pendulous rather than erect to suberect, non-fluffy inflorescences, and the persistant style base of M. sinclairii is about the same length as the nut, and though rather narrow is quite conspicuous. In Machaerina complanata the style-base though persistant , is usually turgid, much shorter than the nut and usually inconspicuous.

Flowering

September - November

Fruiting

November - March (but fruits of varying ages may be found throughout the year)

Propagation Technique

Difficult and should not be removed from the wild. Fresh seed germinates easily (usually within 1-3 months) but plants resent root disturbance and seedlings need to be handled with care as any root damage will kill them. Once seedlings establish it is easy to grow. Does well in wet or dry but prefers full sun. Experimentation with growing conditions at Oratia Native Plant Nurseries showed this species does best when planted in fresh, untreated pine saw dust. Seed set varies from year to year, and there is some indication that it has mast years. For example, 2005 was a particularly good seeding year, while the previous four years were not.

Threats

At all known sites seedlings are scarce (or absent altogether). Many populations are senescent or flower infrequently, and few are on protected land. Indications are that this is a light demanding plant which in the wild is succumbing to natural succession. In heavy shade plants will not flower. In the past this species was regarded as highly threatened, and at that time the key threat had been habitat loss caused by wetland drainage. Recent discoveries over the last 15 or so years indicate that this species is not necessarily confined to wetlands, and potentially can grow in any suitably open habitat.

Chromosome No.

2n = c.50

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 12 Dec 2014