Ehrhartoideae

Rice Oryza sativa, from here.

Belongs within: Poaceae.

The Ehrhartoideae are a clade of grasses supported primarily by molecular data, characterised by the presence of one female-fertile floret per spikelet (Grass Phylogeny Working Group 2001). The most economically significant member of the clade is undoubtedly Oryza sativa, the rice plant.

Characters (from Grass Phylogeny Working Group 2001): Plants annual or perennial (rhizomatous or stoloniferous), herbaceous to suffrutescent, of forests, open hillsides or aquatic habitats. Culms hollow or solid. Leaves distichous; abaxial ligule absent; adaxial ligule a fringed or unfringed membrane, or a fringe of hairs; blades rarely basally cordate or sagittate (Phyllorachideae), somewhat broad to usually narrow, sometimes pseudopetiolate, venation parallel; sheaths sometimes bearing auricles. Inflorescences paniculate or racemose, bracts outside of the spikelets rarely present (Humbertochloa). Spikelets bisexual or unisexual, with glumes 2 (absent in some Oryzeae), sterile florets 0 to 2, and female-fertile floret 1, disarticulating above the glumes or infrequently primary branches disarticulating as units; lemma lacking uncinate macrohairs, if awned, the awn single; palea well developed; lodicules 2, membranous or rarely fleshy, heavily vascularized; stamens usually 3 or 6 (sometimes 1, 2, or 4); ovary glabrous, apical appendage absent, haustorial synergids absent, styles 2, free, fused basally or for their full length (Zizaniopsis), close, stigmas 2. Caryopsis with the hilum long-linear; endosperm hard, without lipid, containing compound starch grains (rarely simple); embryo small, epiblast usually present (absent in Ehrharta), scutellar cleft usually present (absent in Leersia and Potamophila), mesocotyl internode absent (present but short in Microlaena), embryonic leaf usually with overlapping margins (meeting in Potamophila). Foliar mesophyll nonradiate, an adaxial palisade layer usually absent, fusoid cells absent or sometimes present (Zizania and Zizaniopsis), arm cells absent or present; Kranz anatomy absent; midrib simple or complex; adaxial bulliform cells present. Foliar stomata with domeshaped or triangular subsidiary cells; bicellular microhairs present, panicoid-type; papillae often present in Oryzeae, otherwise absent.

<==Ehrhartoideae [Oryzoideae]
    |  i. s.: Zizania aquatica GPWG01, BB01
    |         Humbertochloa GPWG01
    |         Zizaniopsis GPWG01
    |         Potamophila GPWG01
    |         Microlaena GPWG01
    |           |--M. avenacea A27
    |           |--M. colensoi A27
    |           |--M. polynoda A27
    |           |--M. stipoides A27
    |           `--M. thomsoni A27
    |         Phyllorachis [Phyllorachideae] GPWG01
    |--Ehrharta [Ehrharteae] GPWG01
    |    |--E. bulbosa GPWG01
    |    |--E. calycina GPWG01
    |    |--E. dura GPWG01
    |    |--E. longiflora GPWG01
    |    `--E. panicea C55
    `--+--Leersia GPWG01
       |    |--L. hexandra GPWG01
       |    |--L. oryzoides GPWG01
       |    `--L. virginica GPWG01
       `--Oryza [Oryzeae] GPWG01
            |--O. longistamina GC05
            |--O. meyeriana SR07
            |    |--O. m. ssp. meyeriana SR07
            |    `--O. m. ssp. granulata SR07
            `--O. sativa Linnaeus 1753 CD07
                 |--O. s. ssp. sativa PP03
                 |--O. s. ssp. indica PP03
                 `--O. s. ssp. japonica PP03

*Type species of generic name indicated

REFERENCES

[A27] Andersen, J. C. 1927. Popular names of New Zealand plants. Transactions and Proceedings of the New Zealand Institute 57: 905-977.

[BB01] Bauer, R., D. Begerow, A. Nagler & F. Oberwinkler. 2001. The Georgefischeriales: A phylogenetic hypothesis. Mycological Research 105 (4): 416-424.

[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. 2. Librairie de Victor Masson: Paris.

[CD07] Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis & M. J. Donoghue. 2007. Towards a phylogenetic nomenclature of Tracheophyta. Taxon 56 (3): E1-E44.

[GC05] Granjon, L., J.-F. Cosson, E. Quesseveur & B. Sicard. 2005. Population dynamics of the multimammate rat Mastomys huberti in an annually flooded agricultural region of central Mali. Journal of Mammalogy 86 (5): 997-1008.

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

[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.

[PP03] Pilot, G., R. Pratelli, F. Gaymard, Y. Meyer & H. Sentenac. 2003. Five-group distribution of the Shaker-like K⁺ channel in higher plants. Journal of Molecular Evolution 56: 418-434.

[SR07] Sankar, R. V., K. Ravikumar, N. M. Ganesh Babu & D. K. Ved. 2007. Botany of Anapady MPCA, Palghat district, Kerala with special emphasis on species of conservation concern. Bulletin of the Botanical Survey of India 49 (1-4): 165-172.