Cenchrus caliculatus
Past favourite plant finalist
Common names
large burr grass, devil grass, owee grass
Biostatus
Native
Category
Vascular
Structural class
Grasses
Detailed description
Robust, through somewhat lax, spreading, clump-forming grass arising from a stout, woody rhizome; culms trailing and rooting freely from lower nodes. Branching initially extravaginal becoming intravaginal. Leaf-sheath longer than internodes, firm papery, keeled, smooth, minutely scabrid on narrow membranous margin and on ribs below collar. Ligule 1.0–1.5 mm, truncate with a densely ciliate rim. Leaf-bade 70–200 × 4–9 mm, linear-lanceolate, rounded-truncate at base, flat, firm, undersides smooth, upper surface minutely scabrid on ribs; margins somewhat thickened, minutely scabrid, tapering to a long acuminate apex. Culm 700 × 2–2.5 mm diameter, terete, more or less angled, internodes minutely pubescent-scabrid on ridges below panicle. Panicle 100–250 × 15 mm, spicate; rachis triangular, slightly winged, densely minutely pubescent-scabrid, bearing ovoid clusters of 1–3 spikelets, hidden amongst bristles and densely, spirally arranged along rachis; clusters 7–10 × 4–7 mm, including involucre of stiff bristles, at first appressed, finally borne at right angles to rachis; bristles retrorsely barbed, very variable in length, 0.5–11.0 mm, outermost smaller, terete, inner more planoconvex with margins densely softly long-ciliate, one bristle in each cluster usually exceeding the others. Spikelets 5–6 mm, 2-flowered, < inner bristles, sessile, glabrous, light green to almost colourless. Glumes hyaline; lower 2–4.5 mm, 1-nerved, upper 4–5 mm, 5-nerved. Lower floret with lemma 4.8–6.0 mm, 5-nerved, scabrid; palea keels ciliate, interkeel minutely hairy, margins scabrid; anthers 1.5–2.0 mm, brown with thick orange-yellow filaments. Upper floret with lemma 5.0–5.5 mm, 5-nerved, finely scabrid-papillose; palea finely scabrid-papillose; anthers as in lower floret. Seed 2.2–2.7 mm, more or less ellipsoid.
Similar taxa
In New Zealand none. Cenchrus caliculatus is a very robust species within the genus. In the Pacific it appears to have declined in favour of the widespread, weed C. echinatus L. That species is very much smaller, and has dark maroon-red to purple inflorescences. It is not closely related to C. caliculatus, and has yet to be found in New Zealand.
Distribution
Indigenous. In New Zealand known from Raoul Island (Kermadec Islands group) only. Formerly widespread across the Pacific, now very rare or extinct thtroughout most of its former range.
Habitat
Strictly coastal. In New Zealand known only from rocky bluffs, associated talus and from beach sands in one small part of Raoul Island. Elsewhere in the Pacific it has been recorded growing on basalt rock exposures both inland and on the coast, on calcarenite, uplifted coral and coral sand.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | At Risk – Naturally Uncommon | Qualifiers: RR, TO
Threats
Unclear. This very large grass has declined markedly over the last 40 years, and is now extinct or scarce over large parts of former range. No one is exactly sure why (W. R. Sykes pers. comm.).
Detailed taxonomy
Family
Poaceae
Synonyms
Cenchrus calyculatus Cav. is an orthographic variant
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–May
Fruiting
December–September
Life cycle and dispersal
Spiny florets are spread by attachment and possibly wind (Thorsen et al., 2009).
Propagation technique
Easy from fresh seed, rooted pieces and node cuttings. very cold sensitive.
Other information
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for April 2007 for the full story.
Etymology
cenchrus: From the Greek cenchros which means millet
caliculatus: From the Greek kalux (in Latin calyx) ‘case of a bud’ or ‘husk’, meaning to have a calyculus or epicalyx (whorls or bracts below the calyx)
Manaaki Whenua Online Interactive Key
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.
CENCAL
Chromosome number
2n = 102
Previous conservation statuses
2017 | At Risk – Naturally Uncommon | Qualifiers: RR, TO
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, TO
2009 | At Risk – Naturally Uncommon | Qualifiers: TO, OL
2004 | Range Restricted
Referencing and citations
References and further reading
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Christchurch, Manaaki Whenua Press. 650 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309.
Attribution
Description modified from Edgar and Connor (2000)
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.