Scientific Name:
Poa imbecilla Spreng. in Biehler, Pl. Nov. Herb. Spreng. 9, no. 14 (1807)
  • Eragrostis imbecilla (Spreng.) Benth., Fl. Austral. 7, 643 (1878) nom. illeg., non Eragrostis imbecilla (R.Br.) Steud. 1854
  • = Poa imbecilla G.Forst., Fl. Ins. Austr. 89 (1786) nom. inval., nom. nud.
  • = Poa sprengelii Kunth, Révis. Gramin. 116 (1829)
  • = Poa matthewsii var. minor Petrie, Trans. & Proc. New Zealand Inst. 34: 393 (1902)
Vernacular Name(s):
Weak poa

Very fine-leaved, light green, shortly rhizomatous, small, lax, perennial tufts 10–50 cm, with conspicuous light-coloured leaf-sheaths, and slender, erect culms » drooping leaves, topped by extremely delicate, green panicles; branching extravaginal; leaf-blades persistent. Leaf-sheath light green, later creamy brown sometimes purplish, membranous, ribbed, glabrous. Ligule 0.2–0.4–(1) mm, apically glabrous, entire, ± rounded, abaxially slightly scabrid. Leaf-blade (2)–5–12–(16) cm × 0.5–1 mm, folded, usually filiform, soft, culm-leaves 1–3 mm wide, flat, minutely scabrid abaxially on midrib towards long, fine, acute, triangular tip, and adaxially just above ligule and on margins. Culm (4)–10–32–(50) cm, nodes swollen, internodes smooth, rarely scabrid below panicle. Panicle (3.5)–8–15–(25) cm, lax and delicate; rachis smooth to finely scabrid above, elongate branches and pedicels filiform, finely scabrid, spreading, with few spikelets. Spikelets 3–4 mm, 3–4–(5)-flowered, light green, often purplish. Glumes ± unequal, obtuse, midnerve often with a few prickle-teeth; lower 0.8–1.5 mm, 1-nerved, linear-lanceolate, upper 1.3–1.8 mm, 3-nerved, ovate-lanceolate; margins finely scabrid. Lemma (1.6)–1.8–2.2 mm, 5-nerved but inner lateral nerves often rather faint, glabrous, margin and nerves near obtuse tip minutely scabrid. Palea 1.2–2 mm, keels obviously ciliate, interkeel and often margins sparsely prickle-toothed. Callus glabrous, very rarely with a few fine hairs. Rachilla 0.5–1 mm, glabrous. Lodicules c. 0.2 mm. Anthers 0.2–0.4 mm. Gynoecium: ovary 0.3 mm; stigma-styles 0.5–0.9 mm. Caryopsis c. 1 × 0.3 mm, tightly enclosed by lemma and palea. 2n= 28. Plate 7A.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 as Poa imbecilla Spreng.]

Indigenous (Endemic)
Bentham, G. 1878: Flora Australiensis. Vol. 7. Reeve, London.
Biehler, J.F.T. 1807 [30 May]: Plantarun Novarum ex Herbario Sprengelii Centarium.
Cheeseman, T.F. 1925: Manual of the New Zealand Flora. Edition 2. Government Printer, Wellington.
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]
Edgar, E. 1986: Poa L. in New Zealand. New Zealand Journal of Botany 24: 425–503.
Forster, J.G.A. 1786: Florulae Insularum Australium Prodromus. Dietrich, Göttingen.
Garnock-Jones, P.J. 1986: South Pacific plants named by K. P. J. Sprengel in 1807. Taxon 35: 123–128.
Kunth, K. S. 1829: Revision des Graminées publiées dans les Nova Genera et species plantarum de Humboldt et Bonpland; précédée d'un travail général sur la famille des graminées, par Charles-Sigismund Kunth. Paris.
Petrie, D. 1902 ("1901"): Descriptions of New Native Plants, and Notes. Transactions and Proceedings of the New Zealand Institute 34: 390–396.