Classification
Class
Magnoliopsida Brongn.
Order
Rosales Bercht. & J.Presl
Family
Rosaceae
Genus
Acaena Mutis ex L.
 Nomenclature
Scientific Name:
Acaena inermis Hook.f., Bot. Antarct. Voy. II. (Fl. Nov.-Zel.) Part I, 54 (1852)
Synonymy:
  • ≡ Acaena microphylla var. inermis (Hook.f.) Kirk, Stud. Fl. New Zealand 134 (1899)
  • = Acaena microphylla var. pallideolivacea Bitter, Biblioth. Bot. 74: 287 (1911)
  • = Acaena microphylla var. robusta Allan, Fl. New Zealand 1, 357 (1961)
Vernacular Name(s):
Blue mountain bidibid; Spineless bidibid; Spineless piripiri
 Description

Rhizomatous perennial; stems mat-forming, c. 1.2 mm diam., < 15 cm long, soon rooting and covered by soil; erect branchlets < 4 cm long. Lvs 1.5–7 cm long; stipules entire, linear; leaflets 11–15, broad-obovate or orbicular-emarginate, 3–7 × 3–7 mm, with 7–12 obtuse teeth, dull grey-glaucous, purplish brown, or pale olive green on both surfaces, with veins and margins of lower surface hairy. Scape 1–5–(7) cm long, pilose; capitulum 4–6 mm diam. at flowering, < 2.5 cm diam. (including spines) at fruiting; florets c. 20; sepals 4; stamens 2; anthers white; styles 2, white; achenes 2. Fr. turbinate, c. 2 × 2 mm, sparsely hairy, with 4 shoulders rounded and not armed, or bearing 1–4 stout red spines < 1.3 cm long and lacking barbs or hairs at tip.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

 Biostatus
Indigenous (Endemic)
 Phenology

Flowering: Nov.–Jan.; Fruiting: Jan.–Apr.

 Bibliography
Bitter, G. 1911: Die Gattung Acaena. Vorstudien zu einer Monographie. Bibliotheca Botanica 74: 249–336.
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]
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. [Not Threatened]
Hooker, J.D. 1852–1853 ("1853"): The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror in the Years 1839–1843, under the command of Captain Sir James Clark Ross. II. Flora Novae-Zelandiae. Part I. Flowering plants. Lovell Reeve, London.
Kirk,T. 1899: The Students' Flora of New Zealand and the Outlying Islands. Government Printer, Wellington, N.Z.