Cyperus ustulatus
Common names
coastal cutty grass, giant umbrella sedge, cyperus
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Sedges
Detailed description
Robust, 0.6–2.0 m tall, with leaves crowded at base of culms. Culms triquetrous, glabrous, striated. Leaves 0.6–1.2 m long, 8–15 mm wide, lamina coriaceous, strongly keeled, multitubular with numerous septa prominent on the abaxial side, margins and keel very sharply and minutely serrulate; sheath brown. Inflorescence a terminal umbel 40–140 mm long, of 6–12 unequal rays; rays usually unbranched, rarely with secondary branches at base; involucre of numerous leaf-like bracts very much > inflorescence. Spikelets 8–13 mm long, numerous, dark brown or yellow-brown, crowded on each ray into a dense spike 35–70 mm. long. Glumes 5–20 in each spikelet, ovate-oblong, obtuse or mucronate, hard, smooth and shining, keeled, red-brown with white nerves, 2–(3) lowermost and 1–2 uppermost glumes smaller, empty, the remainder fertile. Stamens with persistent filaments. Nut 1.5–2 × c. 0.5 mm., c. ½ length of glume, linear-oblong, trigonous, brown.
Similar taxa
Distinguished from Cyperus insularis by its light green leaves (C. insularis has grey-green leaves and involucral bracts). It has a brown adaxial midrib whereas C. insularis is grey-green. Its leaf sheaths are brown to red-brown and are rigid and hard (whereas in C. insularis they are light pink to purple-pink and flexible and soft). The culm in C. ustulatus is green, distal 5–15 mm is always brown to red-brown and long persistent after flowering. The culm of C. insularis is green, rarely pale brown in distal part and is upright at flowering but weakens and collapses at seed fall after flowering. There are other floral characters which also distinguish these species, for these and other details see Heenan & de Lange (N.Z.J.Bot. 43: 351–359 (2005)—link provided below).
Distribution
Abundant in the North Island and northern South Island, west to Fiordland, and not threatened. Naturally uncommon at its eastern South Island limit, where it is known only from Tai Tapu, Motukarara, Banks Peninsula and the Rakaia River mouth. Also on the Chatham Islands, where it is not very common.
Habitat
Coastal to lowland sites in open ground. Tolerant of a wide range of habitats and conditions but evidently preferring wetland margins, seepages, streamsides, lagoon and estuary margins.
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 | Not Threatened
Detailed taxonomy
Family
Cyperaceae
Synonyms
Mariscus ustulatus (A.Rich.) C.B.Clarke, Cyperus ustulatus f. grandispiculosus Carse ex Kük.
Taxonomic notes
In many populations seed is not formed due to the endemic smut fungus Bauerago (Ustilago) gardneri (Vankey) Vankey which infects the spikes. Infected spikes can be recognised by the abundance of pollen-like yellow powder—the fruiting bodies of the smut fungus—within the spikelets. Plants bearing this smut were formerly thought to be a genetic form and were named Cyperus ustulatus f. grandispiculosus Carse ex Kük.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
July–December
Fruiting
July–April
Life cycle and dispersal
Nuts are dispersed by water, granivory and attachment (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed, and often self sows in gardens. A quite attractive plant now prove popular in cultivation. However it should be planted with caution, the leaf, keel and culm margins are very sharp and can cause very deep cuts.
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). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Cultivation
Over the last decade this species has become very popular and is now widely sold by most nurseries either as Cyperus ustulatus or Mariscus ustulatus.
Etymology
cyperus: From the ancient Greek name for sedge, kypeiros
ustulatus: Burned or scorched
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.
CYPUST
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Heenan PB, de Lange PJ. 2005. Cyperus insularis (Cyperaceae), a new species of sedge from northern New Zealand. New Zealand Journal of Botany 43: 351-359: https://doi.org/10.1080/0028825X.2005.9512958.
Moore LB, Edgar E. 1970. Flora of New Zealand, Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Government Printer, Wellington, NZ. 354 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 adapted from Moore and Edgar (1970)
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.