Green Bastard Grass, Bastard Grass, Hook Sedge
Uncinia caespitosa Boott var. viridis (C.B.Clarke) Hamlin; Uncinia compacta R.Br. var. viridis C.B.Clarke
Vascular – Native
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.
2n = 88
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.
2012 | At Risk – Naturally Uncommon | Qualifiers: DP, Sp
Previous conservation statuses
2009 | At Risk – Naturally Uncommon
2004 | Sparse
Endemic. North, South and Stewart islands. In the North Island found mainly in and around the Central Volcanic Plateau and the adjoining main axial mountain ranges. In the South Island more widespread from Nelson to Otago and probably Southland. Said to be common on Stewart Island.
Montane to alpine in wet hollows within tussock grassland and herbfield. Never common.
Openly caespitose to shortly rhizomatous bright green sedge. Culms 20-250 mm long, usually < 1 mm diameter, glabrous; basal bracts dull yellow-brown to dark brown. Leaves 7-8 per culm, equal to or less than culms, 1.5-2 mm wide, channelled, somewhat rigid, curving downwards, coriaceous, bright green, glossy, scabrid on margins and undersides. spikes 15-50 x 3-4 mm, sometimes bracteate, female flowers 5-15, close-set, internodes 1-2 mm. Glumes > utricles, deciduous, ovate, subacute to acuminate, pale brown-green to light brown, membranous. Utricles 4.5-5 x 1.5 mm, trigonous, ovate, green to grey-brown, rather dull, smooth aside from prominent lateral nerves, slightly pinched below a 1 mm long stipe, and tapered above to a 1.5 mm long beak.
Rather similar to Uncinia divaricata Boott in Hook.f. from which it is well marked by its bright green rather than yellow-green to brown-green foliage and culms. It also differs by its fewer flowered spikelets. Plants could be confused with U. caespitosa Boott in Hook.f. but that species has longer culms,broader dark green leaves and spikes with 10-40 flowers (5-15 in U. viridis). The utricles of U. caespitosa are 5-7 rather than 4.5-5 mm long and wider (1.5-2 cf. c.1.5 mm).
October - December
October - June
Easily grown from fresh seed and by the division of established plants. Prefers a damp spot in full sun. Dislikes excessive humidity and will not tolerant prolonged drought.
A naturally uncommon, biologically sparse species occurring in widely scattered, sometimes quite extensive populations.
uncinia: From the Latin uncus ‘hook’, meaning hooked or barbed
viridis: From the Latin viridis ‘green’
Where To Buy
Not commercially available.
Fact Sheet Prepared by P.J. de Lange (1 August 2004). Description based on Moore & Edgar (1961) - see also Lehnbach (2011) where this species is treated as a synonym of Uncinia rupestris.
References and further reading
Lehnebach, C.A. 2011: Re-evaluating species limits in Uncinia angustifolia, U. caespitosa s.str., U. rupestris, U. viridis and U. zotovii (Cyperaceae). Australian Systematic Botany 24: 405-420.
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Uncinia viridis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/uncinia-viridis/ (Date website was queried)