P.W Michael

Plants annual or perennial; with or without rhizomes. Culms 10-460 cm, prostrate, decumbent or erect, distal portions sometimes floating, sometimes rooting at the lower nodes; nodes usually glabrous; internodes hollow or solid. Sheaths open, compressed; auricles absent; ligules usually absent but, if present, of hairs; blades linear to linear-lanceolate, usually more than 10 times longer than wide, flat, with a prominent midrib. Inflorescencesterminal, panicles of simple or compound spikelike branches attached to elongate rachises, axes not terminating in a bristle, spikelets subsessile, densely packed on the angular branches; disarticulation below the glumes (cultivated taxa not or tardily disarticulating). Spikelets plano-convex, with 2(3) florets; lower florets sterile or staminate; upper florets bisexual, dorsally compressed. Glumes membranous; lower glumes usually 1/4-2/5 as long as the spikelets (varying to more than 1/2 as long), unawned to minutely awn-tipped; upper glumes unawned or shortly awned; lower lemmas similar to the upper glumes in length and texture, unawned or awned, awns to 60 mm; lower paleas vestigial to well-developed; upper lemmas coriaceous, dorsally rounded, mostly smooth, apices short or elongate, firm or membranous, unawned; upper paleas free from the lemmas at the apices; lodicules absent or minute; anthers 3. Caryopses ellipsoid, broadly ovoid or spheroid; embryos usually 0.7-0.9 times as long as the caryopses. x = 9. Name from the Greek echinos, hedgehog, and chloa, grass, in reference to the bristly or often awned spikelets.

Echinochloa is a tropical to warm-temperate genus of 40-50 species that are usually associated with wet or damp places. Many of the species are difficult to distinguish because they tend to intergrade. Some of the characters traditionally used for distinguishing taxa, e.g., awn length, are affected by the amount of moisture available; others reflect selection by cultivation, e.g., non-disarticulation in grain taxa, mimicry of rice as weeds of rice fields. There are 13 species in the Flora region: five native and one possibly native, four established, two grown as commercial crops, and one in research.

In North America, the most abundant species appears to be the introduced, weedy Echinochloa crus-galli, which closely resembles the native E. muricata. The confusion between the two species has caused them to be treated as the same species. This confusion is likely reflected in the mapping of both Echinochloa crus-galli and E. muricata. Echinochloa frumentacea and E. esculenta are grown for grain in India and in China and Japan, respectively, but not in North America. Echinochloa oryzoides and E. oryzicola are weeds whose success and distribution reflects their adaptation to the periodic inundations of commercial rice fields.

Cytogenetic data suggest that E. frumentacea and E. esculenta are domesticated derivatives of E. colona and E. crus-galli, respectively (Yabuno 1962) and that E. oryzoides is very closely related to E. crus-galli (Yabuno 1984). Molecular work (Yamaguchi et al. (2005) are consisten with the cytogenetic daa with respect to the origin of the two domesticated taxa and places E. oryzoides in the unresolved clade that includes E. crus-galli and E. esculenta. Yabuno (1966) suggested that E. crus-galli is an allohexaploid produced by natural hybridization between the tetraploid E. oryzicola with a not-yet-discovered diploid species of Echinochloa and subsequent chromosome doubling. Studies using seed protein electrophoresis and isozyme analyses (Kim et al. 1989; González-Andrés et al. 1996; Asíns et al. 1999), and molecular studies involving RAPD markers and DNA sequences (Hilu 1994; Roy et al. 2000) or PCR-RFLP techniques (Yasuda et al. 2001), will help in clarifying the phylogenetic problems in Echinochloa, providing that proper attention is paid to the morphological characterization of the plant materials used and voucher specimens are made.

The map for Echinochloa polystachya has been amended (see comment), the correct varietal epithet for Echinochloa crus-pavonis should be var. macera [for additional comments on the correct varietal epithet, click here], and a reference supporting use of 'colona' for the epithet of E. colona added.

SELECTED REFERENCES Asíns, M.J., J.L. Carretero, A. Del Busto, E.A. Carbonell, and D. Gomez de Barreda. 1999. Morphologic and isozyme variation in barnyard grass (Echinochloa) weed species. Weed Technol. 13:209-215; Barrett, S.C.H. and D.E. Seaman. 1980. The weed flora of California rice fields. Aquatic Bot. 9:351-376; Carretero, J.L. 1981. El género Echinochloa Beauv. en el sudeste de Europa. Anales Jard. Bot. Madrid 38:91-108; Fishbein, M.1995. Noteworthy collections: Arizona. Madroño 42:83; González-Andrés, F., J.M. Pita, and J.M. Ortiz. Caryopsis isoenzymes of Echinocloa [sic] weed species as an aid for taxonomic discrimination. J. Hort. Sci. 71:187-193; Gould, F.W., M.A. Ali, and D.E. Fairbrothers. 1972. A revision of Echinochloa in the United States. Amer. Midl. Naturalist 87:36-59; Hilu, K.W. 1994. Evidence from RAPD markers in the evolution of Echinochloa millets (Poaceae). Pl. Syst. Evol. 189:247-257; Hitchcock, A.S. 1913. Mexican grasses in the United States National Herbarium. Contr. U.S. Natl. Herb. 17³:181-389; Jauzein, P. 1993. Le genre Echinochloa en Camargue. Monde Pl. 88, no. 446:1-5; Kim, K.V., J.H. Kim, and I.J. Lee. 1989. Biochemical identification of Echinochloa species collected in Korea. Proc. Conf. Asian-Pacific Weed Sci. Soc. 12th [Proc. II]:519-531; Kobayashi, H.and S. Sakamoto. 1990. Weed-crop complexes in cereal cultivation. Pp. 67-80 inS. Kawano (ed.). Biological Approaches and Evolutionary Trends in Plants. Academic Press, London, England and San Diego, California, U.S.A. 417 pp.; Michael, P.W. 1983. Taxonomy and distribution of Echinochloa species with a special reference to their occurrence as weeds of rice. Pp. 291-306 in International Rice Research Institute. Proc. Conf. Weed Control in Rice (31 Aug.-4 Sept. 1981). International Rice Research Institute, Los Baños, Laguna, Philippines. 422 pp.; Michael, P.W. 2001. The taxonomy and distribution of Echinochloa species (barnyard grasses) in the Asian-Pacific region, with a review of pertinent biological studies. Proc. Conf. Asian-Pacific Weed Sci. Soc. 18th [Proc. I]:57-66; Nicolson, D.H. 1986. Species epithets and gender information. Taxon 35:323-328; Roy, S., J.-P. Simon, and F.-J. Lapointe. 2000. Determination of the origin of the cold-adapted populations of barnyard grass (Echinochloa crus-galli) in eastern North America: A total-evidence approach using RAPD DNA and DNA sequences. Canad. J. Bot. 78:1505-1513; Vickery, J.W. 1975. Echinochloa Beauv. Pp. 189-211 in J.W. Vickery. Flora of New South Wales, No. 19, Gramineae, Part 2 (ed. M.D. Tindale). New South Wales Department of Agriculture, Contributions from the New South Wales National Herbarium Flora Series. National Herbarium of New South Wales, Sydney, New South Wales, Australia. 181 pp.; Wunderlin, R.P. 1988. Guide to the Vascular Plants of Florida. University Press of Florida, Gainesville, Florida, U.S.A. 806 pp.; Yabuno, T. 1962. Cytotaxonomic studies on the two cultivated species and the wild relatives in the genus Echinochloa. Cytologia 27:296-305; Yabuno, T. 1966. Biosystematic study of the genus Echinochloa. J. Jap. Bot. 19:277-323; Yabuno, T. 1984. A biosystematic study on Echinochloa oryzoides (Ard.) Fritsch. Cytologia 49:673-678; Yabuno, T. and H. Yamaguchi. 1996. Hie no hakubutsugaku [A natural history of Echinochloa]. Dow Chemicals and Dow Elanco, Tokyo, Japan. 196 pp. [In Japanese]; Yamaguchi, H. A. Utano, K. Yasuda, A. Yano, and A. Soejima. 2005. A molecular phylogeny of wild and cultivated Ehinochloa in East Asia inferred from non-coding region sequences of trnT-L-F. Weed Biology and Management 5:210-218..Yasuda, K., A. Yano, Y. Nakayama, and H. Yamaguchi. 2001. Identification of Echinochloa oryzicola and E. crus-galli using PCR-RFLP technique. [Abstract]. J. Weed Sci. Technol. 46, Suppl.:204-205. [Text in Japanese, title in Japanese and English].

T.A. Cope (1995) Echinochloa. Flora of Somalia 4: 222-224

Plants annual or perennial. Leaves: ligules a line of hairs or absent. Inflorescences panicles of spikelike branches distributed along an elongated central axis. Spikelets paired or in short secondary branches, typically desnsely packed in 4 rows, narrowly elliptic to subrotund, flat on one side, gibbous on the other, often hispidulous, tips cuspidate orawned; glumes acute to acuminate; lower glumes about 1/3 the length of the spikelets; lower florets male or sterile, lemmas often stiffly awned, with or without paleas; upper lemmas crustaceous, smooth and glossy, margins inrolled and clasping only the palea edges, tips terminating in a short membranous, laterally compressed, incurved beaks; upper paleas acute, tips shortly reflexed and slightly protrubing from the lemmas. Caryopses broadly ellpitic, dorsally flattened.

Echinochloa includes 30-40 species. They grow in tropical and warm temperate regions throughout the world. Five species grow in Somaliland and Somalia.

Key to the species of Echinochloa in Somaliland and Somalia.

Global distribution of Echinochloa.

Note: GBIF records include introduced and cultivated plants. Consequently, the distribution shown often differs from statements about a taxon's native distribution.

Asíns, M.J., J.L. Carretero, A. Del Busto, E.A. Carbonell, and D. Gomez de Barreda. 1999. Morphologic and isozyme variation in barnyard grass (Echinochloa) weed species. Weed Technol. 13:209-215.

Barrett, S.C.H. and D.E. Seaman. 1980. The weed flora of California rice fields. Aquatic Bot. 9:351-376.

Carretero, J.L. 1981. El género Echinochloa Beauv. en el sudeste de Europa. Anales Jard. Bot. Madrid 38:91-108.

Fishbein, M. 1995. Noteworthy collections: Arizona. Madroño 42:83.

González-Andrés, F., J.M. Pita, and J.M. Ortiz. Caryopsis isoenzymes of Echinocloa [sic] weed species as an aid for taxonomic discrimination. J. Hort. Sci. 71:187-193

Gould, F.W., M.A. Ali, and D.E. Fairbrothers. 1972. A revision of Echinochloa in the United States. Amer. Midl. Naturalist 87:36-59.

Hilu, K.W. 1994. Evidence from RAPD markers in the evolution of Echinochloa millets (Poaceae). Pl. Syst. Evol. 189:247-257.

Hitchcock, A.S. 1913. Mexican grasses in the United States National Herbarium. Contr. U.S. Natl. Herb. 173:181-389.

Jauzein, P. 1993. Le genre Echinochloa en Camargue. Monde Pl. 88, no. 446:1-5.

b 1989. Biochemical identification of Echinochloa species collected in Korea. Proc. Conf. Asian-Pacific Weed Sci. Soc. 12th [Proc. II]:519-531.

Kobayashi, H.and S. Sakamoto. 1990. Weed-crop complexes in cereal cultivation. Pp. 67-80 inS. Kawano (ed.). Biological Approaches and Evolutionary Trends in Plants. Academic Press, London, England and San Diego, California, U.S.A. 417 pp.; 

Michael, P.W. 1983. Taxonomy and distribution of Echinochloa species with a special reference to their occurrence as weeds of rice. Pp. 291-306 in International Rice Research Institute. Proc. Conf. Weed Control in Rice (31 Aug.-4 Sept. 1981). International Rice Research Institute, Los Baños, Laguna, Philippines. 422 pp.

Michael, P.W. 2001. The taxonomy and distribution of Echinochloa species (barnyard grasses) in the Asian-Pacific region, with a review of pertinent biological studies. Proc. Conf. Asian-Pacific Weed Sci. Soc. 18th [Proc. I]:57-66

Nicolson, D.H. 1986. Species epithets and gender information. Taxon 35:323-328.

Roy, S., J.-P. Simon, and F.-J. Lapointe. 2000. Determination of the origin of the cold-adapted populations of barnyard grass (Echinochloa crus-galli) in eastern North America: A total-evidence approach using RAPD DNA and DNA sequences. Canad. J. Bot. 78:1505-1513. 

Vickery, J.W. 1975. Echinochloa Beauv. Pp. 189-211 in J.W. Vickery. Flora of New South Wales, No. 19, Gramineae, Part 2 (ed. M.D. Tindale). New South Wales Department of Agriculture, Contributions from the New South Wales National Herbarium Flora Series. National Herbarium of New South Wales, Sydney, New South Wales, Australia. 181 pp.

Wunderlin, R.P. 1988. Guide to the Vascular Plants of Florida. University Press of Florida, Gainesville, Florida, U.S.A. 806 pp. 

Yabuno, T. 1962. Cytotaxonomic studies on the two cultivated species and the wild relatives in the genus Echinochloa. Cytologia 27:296-305.

Yabuno, T. 1966. Biosystematic study of the genus Echinochloa. J. Jap. Bot. 19:277-323.

Yabuno, T. 1984. A biosystematic study on Echinochloa oryzoides (Ard.) Fritsch. Cytologia 49:673-678.

Yabuno, T. and H. Yamaguchi. 1996. Hie no hakubutsugaku [A natural history of Echinochloa]. Dow Chemicals and Dow Elanco, Tokyo, Japan. 196 pp. [In Japanese].

Yamaguchi, H. A. Utano, K. Yasuda, A. Yano, and A. Soejima. 2005. A molecular phylogeny of wild and cultivated Ehinochloa in East Asia inferred from non-coding region sequences of trn