Simplicia buchananii (Zotov) Zotov, New Zealand J.Bot. 9: 542 (1971)

de Lange, Peter J., Smissen, Rob D., Rolfe, Jeremy R. & Ogle, Colin C., 2016, Systematics of Simplicia Kirk (Poaceae, Agrostidinae) - an endemic, threatened New Zealand grass genus, PhytoKeys 75, pp. 119-144 : 128-130

Simplicia buchananii (Zotov) Zotov, New Zealand J.Bot. 9: 542 (1971)

≡ Poa uniflora Buchanan Indig. Grasses N.Z. t49B (1880) non Muhl. (1817)

≡ Simplicia laxa var. buchananii Zotov T.R.S.N.Z. 73: 236 (1943)

Holotype.

' Mt Arthur' A. McKay s.n., 1874, (WELT SP059605 !) (fide Zotov 1971).

Etymology.

Named by Zotov (1971) for John Buchanan FLS (1819-1898), Scottish born draughtsman, and New Zealand’s first government employed botanist ( Taylor 2002). Buchanan first described Simplicia buchananii as a species of Poa , Poa uniflora Buchanan but that species name was preoccupied ( Poa uniflora Muhl.) ( Zotov 1971).

Description

(Fig. 5 ). Plants gracile, tufted, 0.40-0.60(-1.0) m tall. Culms 0.40-0.80 m long, bright green when fresh, wiry, erect (sometimes with apices weakly pendant), culm internodes 3-5, elongated, glabrous; internodes ± equal in length to subtending leaf-sheaths. Culm-nodes slightly swollen when fresh, glossy orange-brown to dark red-brown (0.1-)0.3-0.4(-0.5) mm long. Basal leaf-sheaths stramineous or dull brown, membranous, strongly ribbed, usually glabrous, sometimes scabrid on ribs or evenly, finely pubescent; hairs when present retrorse to patent, minute (0.06-0.08 mm long); mid stem and upper leaf-sheaths stramineous to green, membranous, strongly ribbed, glabrous. Ligule 2.0-3.5(-4.0) mm, membranous, lanceolate, apex erose to very deeply lacerate; glabrous. Leaf-blade 100-200 × (1.8-)3.0(-4.0) mm, green to yellow-green, flat, linear-lanceolate with acuminate apices, finely ribbed; adaxial ribs finely scabrid, abaxial ribs glabrous; margins smooth. Panicle (40-)160(-180) mm long, linear; rachis glabrous, branches (10-)30(-36) mm long, erect, glabrous (sometimes bearing minute antrorse prickle-teeth near pedicels), bearing spikelets almost to base, pedicels 0.6-1.0(-1.2) mm long, ± glabrous (sometimes bearing sparse, minute, antrorse prickle-teeth), ± appressed to branchlets. Spikelets 2.8-3.0 mm, 1(-2)-flowered, lanceolate, light green to stramineous. Glumes green ( ± hyaline), glabrous, ovate-lanceolate to ovate, acute to subacute, 1-nerved, lower and upper glume margins entire, ciliate; lower glume 0.3-1.0 mm, upper glume 1.0(-1.6) mm. Lemma 2.6-3.0 mm, light green to grey, scabrid (densely covered in minute prickle-teeth), 3(-5)-nerved, ovate-lanceolate, acute to mucronate, sometimes with a minute subapical awnlet 0.06-0.08 mm long. Palea 2.4-2.8 mm, scabrid (densely covered in minute prickle-teeth), lanceolate, pale green to green, pubescent, 1-2-nerved. Rachilla prolongation 0.3-0.5 mm, filiform, hyaline, glabrous. Stamens 3. Filaments 0.3 mm long, hyaline. Anthers 0.7-1.5 mm, purple or yellow. Ovary narrowly ovoid to weakly trigonous 1.0-1.25 mm long, green, ± glabrous (basal portion sometimes minutely ciliate); styles apical, 0.10-0.25 mm, hyaline; stigmas plumose, white. Caryopsis 1.3-1.5 mm long, laterally compressed, orange when mature. Chromosome number: 2 n = 28 ( Zotov 1971).

Specimens seen.

North-West Nelson, Gouland Downs, A.P. Druce s.n., Jan 1969, WELT SP069213 ; North-West Nelson, Cobb Valley , Chaffey’s Stream, A.M. Hamilton s.n., 23 Feb 1965, CHR 119546; North-West Nelson, Peel Range, above Lake Henderson , A.P. Druce s.n., Mar 1982, CHR 369973; North-West Nelson, below Balloon Hut, I.M. Ritchie s.n., 29 Mar 1967, CHR 175738; North-West Nelson, Kahurangi National Park , Cundy Creek , M.J. Thorsen 101/09, 11 Apr 2009, AK 304802 ; North-West Nelson, Kahurangi National Park , west of Gordon's Pyramid , M.J. Thorsen 106/09, 12 Apr 2009, AK 305801 ; North-West Nelson, Mt Arthur ,? A. Mackay s.n., c.1879, CHR 13277 ; North-West Nelson , South Arthur Range , west side of Baton Saddle, A.P. Druce 478, Feb 1991, CHR 469403; North-West Nelson , Lockett Range , near Ruby Lake, A.P. Druce s.n., Jan 1982, CHR 387666-387667; North West of Mt FZ (between Glenroy and Sheriff Rivers), A.P. Druce s.n., 13 Mar 1984, CHR 394262 .

Distribution

(Fig. 1 ). Simplicia buchananii is endemic to North-West Nelson, South Island.

Recognition.

Simplicia buchananii is distinguished from Simplicia laxa and Simplicia felix by the tufted growth habit, erect culms, and by the linear inflorescences, whose branches are usually tightly appressed to the rachises (Fig. 5 , for other differences see Table 1 ).

Ecology.

Simplicia buchananii is a biologically sparse species of calcareous rock habitats (including shaded rock outcrops, boulderfalls, rock overhangs and cave entrances) within montane forest ( de Lange et al. 2010).

Conservation status.

Using the New Zealand Threat Classification System ( Townsend et al. 2008) Simplicia buchananii has been assessed as 'Threatened / Nationally Critical’ with the qualifiers ‘DP’ [Data Poor], ‘RR’ [Range Restricted] and ‘Sp’ [Sparse] (de Lange et al. 2013). The threats this species faces were summarised by de Lange et al. (2010) and Smissen et al. (2011). Based on our current knowledge of this species the current threat status remains appropriate.

Figures

Figure 1. Distribution of Simplicia species and showing locations discussed in text.

Figure 5. Simplicia buchananii. A habitat, Kahurangi National Park, North West Nelson, South Island, New Zealand B growth habit and inflorescence C culm, leaf base, sheath and ligule D spikelet showing reduced glumes and lemma (images: J. R. Rolfe).