Trisetum

Belongs within: Pooideae.

Trisetum is a genus of about seventy species of grasses found in temperate parts of the world. Lemmas commonly bear an awn above the middle of the back but this is absent in the North American species T. wolfii (Hickman 1993). Trisetum spicatum is a Holarctic species with leaves generally basal and tufted, and inflorescences generally spike-like and dense with spreading awns (Hickman 1993).

Characters (Flora of China): Perennials, tufted, sometimes shortly rhizomatous. Leaf blades narrowly to broadly linear, usually flat; ligule membranous. Inflorescence a moderately lax to spikelike panicle, shining. Spikelets with 2 or 3 florets, disarticulating below each floret; rachilla shortly bearded, extended beyond uppermost floret, tipped by a reduced or vestigial floret; glumes lanceolate, unequal or subequal, shorter than spikelet, keeled, herbaceous or membranous, margins broad, hyaline, lower glume 1(–3)-veined, upper glume 3-veined, apex acute or acuminate; floret callus glabrous or shortly bearded; lemmas lanceolate, laterally compressed, membranous to thinly leathery, 5-veined, glabrous, awned from above middle of back, apex 2-toothed, teeth often aristulate; awn geniculate with twisted column or merely outwardly curved; palea hyaline, slightly to distinctly shorter than lemma, gaping free from lemma margins. Ovary glabrous or almost so. Caryopsis with punctiform hilum; endosperm sometimes liquid.

<==Trisetum
    |--T. aeneumO88
    |--T. antarcticum Trin. 1831 [=Aira antarctica, Avena antarctica]C06
    |    |  i. s.: T. a. var. lasiorhachis Hack. in Cheeseman 1906C06
    |    |--T. a. ssp. antarcticumW91
    |    `--T. a. ssp. tenellumW91
    |--T. canescens [=T. cernuum var. canescens; incl. T. cernuum var. projectum]H93
    |--T. cernuumH93
    |--T. cheesemanii Hack. 1903C06
    |--T. flavescensH93
    |--T. melicoidesV72
    |--T. pumilumG52
    |--T. saxeticolum Cockayne & Allan 1927CA27
    |--T. scitulumO88
    |--T. serpentinumHL01
    |--T. spicatumO88
    |    |  i. s.: T. s. var. pilosiglumeV72
    |    |--T. s. ssp. spicatumO88
    |    `--T. s. ssp. himalaicumO88
    |--T. subspicatumCA27 [=Avena subspicataC55]
    |    |--T. s. var. subspicatumD03
    |    `--T. s. var. glabrifoliumD03
    |--T. wolfiiH93
    `--T. youngiiC06

*Type species of generic name indicated

References

[C55] Candolle, A. de. 1855. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 1. Librairie de Victor Masson: Paris.

[C06] Cheeseman, T. F. 1906. Manual of the New Zealand Flora. John Mackay, Government Printer: Wellington.

[CA27] Cockayne, L., & H. H. Allan. 1927. Notes on New Zealand floristic botany, including descriptions of new species, &c. (No. 5). Transactions and Proceedings of the New Zealand Institute 57: 48–72.

[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).

[G52] Gardner, C. A. 1952. Flora of Western Australia vol. 1 pt 1. Gramineae. William H. Wyatt: Perth.

[HL01] Heenan, P. B. & P. J. de Lange. 2001. A new, dodecaploid species of Uncinia (Cyperaceae) from ultramafic rocks, Surville Cliffs, Northland, New Zealand. New Zealand Journal of Botany 39: 373–380.

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

[O88] Ohba, H. 1988. The alpine flora of the Nepal Himalayas: an introductory note. In: Ohba, H., & S. B. Malla (eds) The Himalayan Plants vol. 1. The University Museum, University of Tokyo, Bulletin 31: 19–46.

[V72] Voss, E. G. 1972. Michigan Flora. Part I. Gymnosperms and Monocots. Cranbrook Institute of Science and University of Michigan Herbarium.

[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.