Avena

Common oats Avena sativa, copyright H. Zell.

Belongs within: Pooideae.

Avena is a genus of grasses including oats Avena sativa and related species, some of which are significant weed species.

Characters (from Z.-L. Wu & S. M. Phillips): Annuals. Culms erect, fairly robust. Leaf blades linear, flat; ligule membranous. Inflorescence a large loose panicle. Spikelets large, pendulous, oblong to gaping, florets 2 to several, the uppermost reduced; rachilla pilose or glabrous, disarticulating below each floret or only below the lowest, or not disarticulating (cultivated species); glumes lanceolate to elliptic, usually subequal and as long as spikelet, rarely strongly unequal or shorter than spikelet, herbaceous to membranous, 7–11-veined, back rounded, smooth, apex acuminate; floret callus acute to pungent, bearded; lemmas lanceolate-oblong, usually leathery, occasionally papery, back rounded, 5–9-veined, glabrous to hispid, awned usually from near middle of back, apex papery, 2-toothed to 2-fid, lobes sometimes extended into fine bristles, awn geniculate with twisted column, sometimes reduced or absent (cultivated species); palea usually shorter than lemma, keels ciliate. Ovary densely hairy. Caryopsis with long linear hilum.

<==Avena
    |--A. barbata Pott ex Link 1800 PL04
    |    |--A. b. ssp. barbata PL04
    |    `--A. b. ssp. atherantha (Presl) Rocha Afonso 1978 PL04
    |--A. brevis D51
    |--A. byzantina D51
    |--A. fatua C55b
    |    |--A. f. var. fatua S06
    |    `--A. f. var. glabrata Petermann 1841 S06
    |--A. hirsuta S06
    |--A. longiglumis GPWG01
    |--A. nuda C55b
    |--A. orientalis C55b
    |--A. pratensis C55a
    |--A. pubescens C06
    |--A. sativa GPWG01
    |--A. sterilis Lin. 1762 S06
    `--A. strigosa D51

*Type species of generic name indicated

REFERENCES

[C55a] Candolle, A. de. 1855a. 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.

[C55b] Candolle, A. de. 1855b. Géographie Botanique Raisonée: Ou exposition des faits principaux et des lois concernant la distribution géographique des plantes de l’époque actuelle vol. 2. Librairie de Victor Masson: Paris.

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

[D51] Dobzhansky, T. 1951. Genetics and the Origin of Species 3^rd ed. Columbia University Press: New York.

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

[PL04] Pohl, G., & I. Lenski. 2004. Zur Verbreitung und Vergesellschaftung von Pennisetum orientale Rich. in Nordeuböa (Griechenland) (Poaceae, Paniceae). Senckenbergiana Biologica 83 (2): 209–223.

[S06] Stuckert, T. 1906. Segunda contribución al conocimiento de las gramináceas Argentinas. Anales del Museo Nacional de Buenos Aires, serie 3, 6: 408–555.