Cyperus ustulatus
Common name
coastal cutty grass, giant umbrella sedge, cyperus
Synonyms
Mariscus ustulatus (A.Rich.) C.B.Clarke, Cyperus ustulatus f. grandispiculosus Carse ex Kük.
Family
Cyperaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Sedges
Current conservation status
The conservation 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). 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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
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.
Features
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 C. 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).
Flowering
July - December
Fruiting
July - April
Life cycle
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.
Etymology
cyperus: From the ancient Greek name for sedge, kypeiros
ustulatus: Burned or scorched
Taxonomic note
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.
Where To Buy
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.
Attribution
Description adapted from Moore and Edgar (1970)
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
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