Pentapogon micranthus
Common name
purple plume grass
Synonyms
Stipa micrantha Cav., Agrostis sciurea R.Br., Dichelachne sciurea (R.Br.) Hook.f., D. crinita var. intermedia Hack., Dichelachne micrantha (Cav.) Domin
Family
Poaceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Grasses
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.
DICMIC
Chromosome number
2n = 70
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 | Threatened – Nationally Vulnerable | Qualifiers: DP, SO, Sp
Previous conservation statuses
2012 | Threatened – Nationally Vulnerable | Qualifiers: DP, SO, Sp
2009 | Threatened – Nationally Vulnerable | Qualifiers: DP, SO, Sp
2004 | Not Threatened
Distribution
Indigenous. Local from Three Kings Islands, and Te Paki south to about Auckland. Also around East Cape and the eastern Wairarapa (northern Aorangi Range). never very common. Outside New Zealand common on Norfolk Island, also known from Australia, New Guinea and Easter Island.
Habitat
Coastal to lowland. Usually in open shrubland, on clay pans or within open grassland. Often on cliff faces, amongst talus, on lava fields on at the back of boulder beaches. Fast becoming scarce.
Features
Stout, rigid, tufted grass with leaves rigid, shorter than the stiffly erect culms. Branching extravaginal. Leaf-sheath straw-coloured often lined with purple or dull brown, with minute, appressed, scattered hairs. Ligule 0.3-1.0 mm long, membranous, truncate, minutely ciliate, undersides scabrid, often asymmetric. Leaf-blade to 200 x 1.5-2.5 mm, stiff, flat, tapered towards apex, undersides sparingly and minutely scabrid, upper surface scabrid on ribs towards apex, minutely scabrid on margins. Culm 0.4-1.0 m, internodes minutely scaberulous throughout, or glabrous but minutely scaberulous below panicle, variously purplish. Panicle 100-250 mm, erect, spicate, often purplish (or tinged with red), branches spreading at first; rachis, branchlets and pedicels closely short-scabrid. Spikelets numerous, close-set on branchlets, delicate. Glumes narrow-lanceolate, acute to acuminate, often suffused with purple or red; lower 3-4 mm long, more or less equivalent in length to lemma, upper 3.5-5.0 mm, greater than lemma. Lemma 2.5-4.0 mm long, sometimes purplish; awn 12-18 mm, very fine, column straight, awn curving above and twisted 2-3 times along whole length, inserted 0.6-0.9 mm below minutely bifid lemma-tip. Palea 2-3 mm long, narrow-linear, keels scabrid above, apex ciliate. Callus hairs 0.3-0.5 mm long. Rachilla prolongation c.0.05 mm long. Lodicules 0.4-0.8 mm long, hyaline, elliptic-oblong, unequally bilobed, sometimes minutely ciliate. Anthers 1, 1.2-1.4 mm long in open flowers, 0.6-0.8 mm long in cleistogamous flowers. Seed 2.0-2.3 x 0.3-0.4 mm.
Manaaki Whenua Online Interactive Key
Similar taxa
Most frequently confused with Pentapogon rarus an eastern Australia species which is now widely naturalised in the North Island and northern South Island. Pentapogon rarus differs from P. micranthus by its usually smaller, narrower panicles, and by the lower glume which is usually greater than rather than shorter than 4 mm long, and obviously much larger than rather than more or less equal in length to the lemma.
Flowering
September - January
Fruiting
October - May
Life cycle
Florets are wind dispersed (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed. Rather short-lived, self sowing readily, and in gardens can be invasive. Does best in dry, open, clay soils.
Threats
Pentapogon micranthus was formerly widespread but over the last 20 years or so its range has contracted considerably. Partly this is due to the progressive loss of the open, coastal shrublands and clay pans it favours, as these give way to taller mature vegetation but mostly it seems to be due to the ever increasing numbers of naturalised plants which are now occupying its favoured habitats. It has been observed that in many of the places it was formerly common, these places are now dominated by Pentapogon rarus, which appears to be expanding its range, and is certainly increasing in abundance.
Etymology
micranthus: Small flower
Where To Buy
Not commercially available.
Attribution
Description modified from Edgar and Connor (2000)
References and further reading
Edgar, E.; Connor, H.E. 2000: Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 pp.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pentapogon micranthus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pentapogon-micranthus/ (Date website was queried)