Danthonioideae

Common wallaby-grass Austrodanthonia caespitosa, from here.

Belongs within: Poaceae.
Contains: Danthonia.

The Danthonioideae is a clade of mostly Southern Hemisphere tussocks and pampas grasses, though the type genus Danthonia has a Holarctic distribution. The genus Pentaschistis is found in Africa whereas Austrodanthonia and Chionochloa are Australasian. Danthonioideae are distinguished from other grasses by the presence of haustorial synergids in the ovule. The pampas grasses of the genus Cortaderia have been widely grown as ornamentals, and have become significant invasives in some parts of the world. Species of Chionochloa, snow tussocks, are a significant part of the high alpine vegetation in New Zealand.

Characters (from Grass Phylogeny Working Group 2011): Plants perennial (caespitose, rhizomatous or stoloniferous) or less commonly annual, herbaceous or rarely suffrutescent, of mesic to xeric open habitats in grasslands, heathlands, and open woodlands. Culms solid or very rarely hollow. Leaves distichous; abaxial ligule usually absent (sometimes present in Cortaderia, Karroochloa and Pentaschistis); adaxial ligule a fringe of hairs or a fringed membrane; blades relatively narrow, without a pseudopetiole, venation parallel; sheaths not auriculate except in Pentameris thuarii. Inflorescences paniculate or less commonly racemose or spicate, bracts outside of the spikelets absent (but the subtending leaf more or less spatheate and disarticulating with the inflorescence in Tribolium pusillum). Spikelets bisexual (but sometimes without bisexual florets in Cortaderia) or unisexual (Cortaderia, Lamprothyrsus), glumes 2 and usually equal, female-fertile florets 1 to 6(to 20), with apical reduction and a rachilla extension usually present, laterally compressed, disarticulating above the glumes and between the florets, less commonly below the glumes; lemma lacking uncinate macrohairs, awn single and from a sinus; palea well developed, sometimes relatively short; lodicules 2, free (rarely joined), fleshy or rarely with an apical membranous flap, glabrous or ciliate, often with microhairs, sometimes heavily vascularized; stamens 3; ovary glabrous or rarely with apical hairs (Pentameris), apical appendage absent, haustorial synergids present, only weakly developed in a few taxa, styles 2, the bases usually widely separated, stigmas 2. Caryopsis with the hilum short or long-linear; endosperm hard, containing compound starch grains (simple in Prionanthium); embryo large or small, epiblast absent, scutellar cleft present, mesocotyl internode elongated, embryonic leaf margins meeting (overlapping in Danthonia decumbens). Basic chromosome numbers: x = 6, 7, 9. Foliar mesophyll nonradiate, an adaxial palisade layer absent, fusoid cells absent, arm cells absent; Kranz anatomy absent; midrib simple, usually with one bundle, an arc of bundles in Cortaderia; adaxial bulliform cells present or absent. Foliar stomata with domeshaped or parallel-sided subsidiary cells (rarely high dome-shaped or slightly triangular); bicellular microhairs present, panicoid-type, sometimes absent; papillae usually absent but often present in Chionochloa and Merxmuellera.

<==Danthonioideae [Danthonieae]
    |--Merxmuellera macowanii GPWG01
    `--+--Danthonia GPWG01
       `--+--Karroochloa purpurea GPWG01
          `--Austrodanthonia GPWG01
               |--A. caespitosa OS04
               |--A. laevis GPWG01
               |--A. occidentalis GK00
               |--A. penicillata B00
               |--A. pilosa B00
               `--A. setacea OS04

Danthonioideae incertae sedis:
  Cortaderia [Cortaderieae] GPWG01
    |--C. araucana D03
    |--C. dioica [=Arundo dioica Spreng. 1825; incl. C. argentea Stapf 1897, Gynerium argenteum] S06
    |--C. jubata AC93
    |--C. pilosa D03
    |--C. rudiuscula S06
    |--C. selloana LH97
    `--C. splendens L97
  Pentaschistis GL06
    |--P. airoides GL06
    |--P. caulescens GL06
    |--P. clavata Galley in Galley & Linder 2006 GL06
    |--P. eriostoma GL06
    |--P. horrida Galley in Galley & Linder 2006 GL06
    |--P. juncifolia Stapf 1899 GL06
    |--P. pallida GL06
    |--P. pictigluma GL06
    |--P. pusilla GL06
    |--P. rigidissima GL06
    |--P. rosea GL06
    |--P. trifida Galley in Galley & Linder 2006 GL06
    `--P. triseta GL06
  Pentameris thuarii GPWG01
  Tribolium pusillum GL06, GPWG01
  Prionanthium GPWG01
  Chionochloa GPWG01
    |--C. australis G01
    |--C. bromoides LM98
    |--C. conspicua W91
    |--C. flavescens W91
    |    |--C. f. ssp. flavescens W91
    |    `--C. f. ssp. lupeola W91
    |--C. juncea NL98
    |--C. oreophila W91
    |--C. pallens WH02
    `--C. rubra W91
         |--C. r. ssp. rubra W91
         `--C. r. ssp. occulta W91
  Chaetobromus GPWG01
  Joycea pallida GPWG01, B00
  Notochloe GPWG01
  Notodanthonia GPWG01
    |--N. caespitosa RL06
    `--N. setacea RL05
  Plinthanthesis GPWG01
    |--P. tenuior B78
    `--P. urvillei B78
  Pseudopentameris GPWG01
  Rytidosperma GPWG01
    |--R. nigricans W91
    `--R. setifolium W91
  Schismus GL06
    |--S. arabicus H93
    `--S. barbatus H93

*Type species of generic name indicated

REFERENCES

[AC93] Atkinson, I. A. E., & E. K. Cameron. 1993. Human influence on the terrestrial biota and biotic communities of New Zealand. Trends in Ecology and Evolution 8 (12): 447-451.

[B78] Bentham, G. 1878. Flora Australiensis: A description of the plants of the Australian Territory vol. 7. Roxburghiaceae to Filices. L. Reeve & Co.: London.

[B00] Braby, M. F. 2000. Butterflies of Australia: their identification, biology and distribution vol. 2. CSIRO Publishing: Collingwood (Victoria).

[D03] Dusén, P. 1903. The vegetation of western Patagonia. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 1–34. The University: Princeton (New Jersey).

[GL06] Galley, C. A., & H. P. Linder. 2006. New species and taxonomic changes within Pentaschistis (Danthonioideae, Poaceae) from Western Cape, South Africa. Bothalia 36 (2): 157–162.

[G01] Gibbs, G. W. 2001. Habitats and biogeography of New Zealand’s deinacridine and tusked weta species. In: Field, L. H. (ed.) The Biology of Wetas, King Crickets and Their Allies pp. 35–55. CABI Publishing: Wallingford (UK).

[GK00] Gibson, N., & G. J. Keighery. 2000. Flora and vegetation of the Byenup-Muir reserve system, south-west Western Australia. CALMScience 3 (3): 323–402.

[GPWG01] Grass Phylogeny Working Group. 2001. Phylogeny and subfamilial classification of the grasses (Poaceae). Annals of the Missouri Botanical Garden 88 (3): 373–457.

[H93] Hickman, J. C. (ed.) 1993. The Jepson Manual: Higher Plants of California. University of California Press: Berkeley (California).

[L97] Lange, P. J. de. 1997. Hebe brevifolia (Scrophulariaceae)—an ultramafic endemic of the Surville Cliffs, North Cape, New Zealand. New Zealand Journal of Botany 35: 1–8.

[LH97] Lange, P. J. de, & P. B. Heenan. 1997. Carex ophiolithica (Cyperaceae): a new ultramafic endemic from the Surville Cliffs, North Cape, New Zealand. New Zealand Journal of Botany 35: 429–436.

[LM98] Lange, P. J. de, & B. G. Murray. 1998. Senecio repangae (Asteraceae): a new endemic species from the north-eastern North Island, New Zealand. New Zealand Journal of Botany 36: 509–519.

[NL98] Norton, D. A., & P. J. de Lange. 1998. Hebe paludosa (Scrophulariaceae)—a new combination for an endemic wetland Hebe from Westland, South Island, New Zealand. New Zealand Journal of Botany 36: 531–538.

[OS04] Obbens, F. J., & L. W. Sage. 2004. Vegetation and flora of a diverse upland remnant of the Western Australian wheatbelt (Nature Reserve A21064). Journal of the Royal Society of Western Australia 87 (1): 19–28.

[RL05] Rafferty, C., & B. B. Lamont. 2005. Selective feeding by macropods on vegetation regenerating following fire. Journal of the Royal Society of Western Australia 88 (4): 155–165.

[RL06] Rafferty, C., & B. B. Lamont. 2006. Food choice by western grey kangaroos among plants grown at different nutrient levels. Journal of the Royal Society of Western Australia 89 (1): 7–12.

[S06] Stuckert, T. 1906. Segunda contribución al conocimiento de las gramináceas Argentinas. Anales del Museo Nacional de Buenos Aires, serie 3, 6: 409–555.

[W91] Williams, P. A. 1991. Subalpine and alpine vegetation of granite ranges in western Nelson, New Zealand. New Zealand Journal of Botany 29: 317–330.

[WH02] Worthy, T. H., & R. N. Holdaway. 2002. The Lost World of the Moa: Prehistoric life of New Zealand. Indiana University Press: Bloomington (Indiana).

Last updated: 25 March 2021.