Classification
 Nomenclature
Scientific Name:
Carex horizontalis (Colenso) K.A.Ford in Global Carex Group, Bot. J. Linn. Soc. 179: 33 (2015)
Synonymy:
  • Uncinia horizontalis Colenso, Trans. New Zealand Inst. 15: 334 (1833)
  • = Uncinia rupestris Raoul, Ann. Sci. Nat., Bot. sér. 3, 2: 117 (1844)
  • = Uncinia compacta var. viridis C.B.Clarke, J. Linn. Soc., Bot. 20: 395 (1883)
  • Uncinia caespitosa var. viridis (C.B.Clarke) Hamlin, 19: 52 (1959)
  • Uncinia viridis (C.B.Clarke) Edgar in Moore & Edgar, Fl. N. Zeal. 2, 229 (1970)
  • = Uncinia compacta var. caespitiformis Kük. in Cockayne, Rep. Bot. Surv. Stewart Island 42 (1909)
 Description

Forming a dense turf. Culms (10)–20–30–(40) cm. × c. 0.5 mm., drooping or nodding, glab., or slightly scabrid just below infl.; basal bracts light brown, not shining. Lvs 4–6–(7) per culm, < mature culms, c. 1.5–2 mm. wide, bright green, soft, channelled, scabrid on margins and upper surface towards tip. Spikes 3–5–(6) cm. × 3–5 mm., occ. bracteate, female fls 5–13–(33), lax towards base of spike with internodes to 6 mm. long, more crowded above with internodes 0.5–1 mm. long. Glumes ± = or us. < utricles, deciduous, ovate, acute or acuminate, hyaline with green midrib or very pale brown. Utricles 4.5–5.5–(6) × 1–1.5 mm., ovate-lanceolate, trigonous, green to greenish brown, us. smooth except for a prominent lateral nerve but occ. with a few less distinct nerves, somewhat spreading when ripe, slightly contracted below to a stipe c. 1–1.5 mm. long, tapering above to a beak of 1–2 mm. long.

[From:  Moore and Edgar (1970) Flora of New Zealand. Volume 2. as Uncinia rupestris Raoul]

 Biostatus
Indigenous (Endemic)
 Bibliography
Clarke, C.B. 1883: On Hemicarex Benth., and its Allies. Journal of the Linnean Society. Botany 20: 374–403.
Cockayne, L. 1909: Report on a Botanical Survey of Stewart Island. Government Printer, Wellington, N.Z.
Colenso, W. 1883: Descriptions of a few new Indigenous Plants. Transactions of the New Zealand Institute 15: 320–339.
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96. [as Uncinia viridis (C.B.Clarke) Edgar] [Naturally uncommon]
de Lange, P.J.; Norton, D.A.; Heenan, P.B.; Courtney, S.P.; Molloy, B.P.J.; Ogle, C.C.; Rance, B.D. 2004: Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42(1): 45–76. [as Uncinia viridis (C.B.Clarke) Edgar]
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series No. 22. [Not Threatened; Taxonomically indistinct]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [as Uncinia rupestris Raoul; Uncinia viridis (C.B.Clarke) Edgar] [Naturally Uncommon; Not Threatened]
Global Carex Group 2015: Making Carex monophyletic (Cyperaceae, tribe Cariceae): a new broader circumscription. Botanical Journal of the Linnean Society 179: 1–42.
Hamlin, B.G. 1959: A Revision of the Genus Uncinia (Cyperaceae Caricoideae) in New Zealand. Dominion Museum Bulletin 19: 1–106.
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. [as Uncinia caespitosa var. viridis (C.B.Clarke) Hamlin; Uncinia compacta var. caespitiformis Kük.; Uncinia compacta var. viridis C.B.Clarke; Uncinia horizontalis Colenso; Uncinia rupestris Raoul; Uncinia viridis (C.B.Clarke) Edgar]
Raoul, E. 1844: Choix de plantes de la Nouvelle-Zélande. Recueillies et décrites par M.E. Raoul. Annales des Sciences Naturelles; Botanique sér. 3, 2: 113–123.