Alismataceae

Description

Plants herbaceous, annual or perennial, with milky sap, glabrous to stellate-pubescent, submersed, floating leaves, or emergent in fresh or brackish waters. Roots fibrous, few to many, septate or aseptate, at base or lower nodes of stem. Stems corm-like, rhizomatous, or stoloniferous, rhizomes occasionally terminated by tubers. Leaves basal, sessile or petiolate; petioles terete to triangular, mostly 2 or more times length of blade, with sheathing base; blades linear, elliptic, ovate to rhomboid, with or without pellucid markings of dots or lines, margin entire or undulate, apex obtuse, acute, or acuminate, base with or without basal lobes, if without basal lobes, then attenuate, if with basal lobes, then truncate, cordate, sagittate, or hastate, venation reticulate, with parallel primary veins from base of blade to apex and reticulate secondary veins. Inflorescences scapose, mostly erect, rarely floating or decumbent, verticillate, forming racemes or verticils branching to become paniculate, rarely umbellate, without a subtending spathe, bracteolate; bracts whorled, linear, delicate to coarse, smooth to papillose, entire, obtuse to acute. Flowers hypogynous, bisexual or unisexual (plants monoecious, rarely dioecious), subsessile to long pedicellate; perianth actinomorphic, of 6 free segments in 2 series, sepals 3, green, persistent, erect and enclosing flower and fruit or spreading to reflexed, petals 3, delicate, larger than sepals, deciduous; stamens absent or of 6 to many, separate, anthers 2-locular, elongate, basifixed or versatile, dehiscing by longitudinal slits; pollen 5-aperturate, globose, separate; gynoecium absent or of 6 to many separate carpels, spirally arranged, carpels 1-locular, each with 1 or rarely 2 anatropous ovules, placentation basal, styles terminal or lateral, persistent, stigmas linear. Achenes compressed or terete, mostly numerous, often winged, longitudinally ribbed or not ribbed, glandular or eglandular; seeds 1-few, U-shaped; endosperm helobial or nuclear in development, absent in mature seeds.

Distribution

Guianas: present Neotropics: present
A worldwide family of about 75 species in 11 genera; in the Neotropics ca. 40 species in 2 genera; in the Guianas 11 species in 2 genera.

Synonymy

Alismataceae sec. Robert R. Haynes& Lauritz B. Holm-Nielsen - Alismataceae in B. Ståhl, G.T. Prance, C.A. Stace, R.R. Haynes, L.B. Holm-Nielsen, I. Poole, J. Koek-Noorman, F. Lens, S. Jansen, L.Y.T. Westra, J.W. Maas & M.J. Jansen-Jacobs, FLORA OF THE GUIANAS, Series A: Phanerogams Fascicle 27 71. CYRILLACEAE, 79. THEOPHRASTACEAE, 86. RHABDODENDRACEAE, 90. PROTEACEAE, 100. COMBRETACEAE, 113. DICHAPETALACEAE, 167. LIMNOCHARITACEAE, 168. ALISMATACEAE, including Wood and Timber. 2009

    Specimens

    CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
    Cowan, R.S. 38878
    Citation: Cowan, R.S. 38878.

    Cremers, G. 5282
    Citation: Cremers, G. 5282.

    Feuillet, C. 779
    Citation: Feuillet, C. 779.

    Granville, J.J. de 1045
    Citation: Granville, J.J. de 1045.

    Granville, J.J. de 6827
    Citation: Granville, J.J. de 6827.

    Guyana, Republic ofAndel, T.R. van, et al. 1107
    Citation: Guyana, Republic of, Andel, T.R. van, et al. 1107.

    Guyana, Republic ofAppun, C.F. 2164
    Citation: Guyana, Republic of, Appun, C.F. 2164.

    Guyana, Republic ofClarke, H.D. 2469
    Citation: Guyana, Republic of, Clarke, H.D. 2469.

    Guyana, Republic ofCollector unknown 388
    Citation: Guyana, Republic of, Collector unknown 388.

    Guyana, Republic ofCook, C.D.K. 207a
    Citation: Guyana, Republic of, Cook, C.D.K. 207a.

    Guyana, Republic ofCook, C.D.K. 21
    Citation: Guyana, Republic of, Cook, C.D.K. 21.

    Guyana, Republic ofCook, C.D.K. 81
    Citation: Guyana, Republic of, Cook, C.D.K. 81.

    Guyana, Republic ofCooper, A. 436
    Citation: Guyana, Republic of, Cooper, A. 436.

    Guyana, Republic ofCremers, G. 5282
    Citation: Guyana, Republic of, Cremers, G. 5282.

    Guyana, Republic ofCruz, J.S. de la 1272
    Citation: Guyana, Republic of, Cruz, J.S. de la 1272.

    Guyana, Republic ofCruz, J.S. de la 4097
    Citation: Guyana, Republic of, Cruz, J.S. de la 4097.

    Guyana, Republic ofForest Dept. G397
    Citation: Guyana, Republic of, Forest Dept. G397.

    Guyana, Republic ofGillespie, L.J., et al. 1186
    Citation: Guyana, Republic of, Gillespie, L.J., et al. 1186.

    Guyana, Republic ofGillespie, L.J., et al. 2006
    Citation: Guyana, Republic of, Gillespie, L.J., et al. 2006.

    Guyana, Republic ofGoodland, R. 812
    Citation: Guyana, Republic of, Goodland, R. 812.

    Guyana, Republic ofGoodland, R. 977
    Citation: Guyana, Republic of, Goodland, R. 977.

    Guyana, Republic ofGörts-van Rijn, A.R.A., et al. 242
    Citation: Guyana, Republic of, Görts-van Rijn, A.R.A., et al. 242.

    Guyana, Republic ofGraham, E.H. 389
    Citation: Guyana, Republic of, Graham, E.H. 389.

    Guyana, Republic ofGrewal, M.S. & R. Persaud 53
    Citation: Guyana, Republic of, Grewal, M.S. & R. Persaud 53.

    Guyana, Republic ofHarrison, S.G. et al. 1562
    Citation: Guyana, Republic of, Harrison, S.G. et al. 1562.

    Guyana, Republic ofHarrison, S.G. et al. 1727
    Citation: Guyana, Republic of, Harrison, S.G. et al. 1727.

    Guyana, Republic ofHekking, W.H.A. 1253
    Citation: Guyana, Republic of, Hekking, W.H.A. 1253.

    Guyana, Republic ofHitchcock, A.S. 16887
    Citation: Guyana, Republic of, Hitchcock, A.S. 16887.

    Guyana, Republic ofHitchcock, A.S. 16997
    Citation: Guyana, Republic of, Hitchcock, A.S. 16997.

    Guyana, Republic ofHitchcock, A.S. 17044
    Citation: Guyana, Republic of, Hitchcock, A.S. 17044.

    Keys