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Najas graminea Delile

Brief Summary

Comprehensive Description

    Najas graminea
    provided by wikipedia

    Najas graminea, also known as ricefield water-nymph[2] is a species of aquatic plant found in freshwater habitats, especially still or slow-moving waters, like ponds and rice fields. It grows to a maximum length of 30 cm. The flowers are monoecious. The flowering season is from July to September.[3][4][5][6]

    The natural distribution of this annual plant covers most of Africa as well as the Middle East, Central Asia, East Asia, Southeast Asia, New Guinea, New Caledonia and northern Australia. It has become naturalized in Spain, Italy, Bulgaria, Crimea and California.[7] This plant is also commercialized in the aquarium trade.

    References

    1. ^ The Plant List
    2. ^ "Najas graminea - Ricefield waternymph -- Discover Life". www.discoverlife.org. Retrieved 2017-01-31..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    3. ^ "Najas graminea Ricefield waternymph PFAF Plant Database". www.pfaf.org. Retrieved 2017-01-31.
    4. ^ Alire Raffeneau Delile. 1813. Description de l'Égypte, . . . Histoire Naturelle, Tom. Second 2: 282, pl. 50, f. 3. Najas graminea
    5. ^ Tzvelev, Nikolai Nikolaievich. 1976. Novosti Sistematiki Vysshikh Rastenii 13: 20, Caulinia graminea
    6. ^ Triest, Ludwig J. 1988. Mém. Acad. Roy. Sci. Outre-Mer, Sci. Nat. Nouv. Sér. 22(1): 143, Najas graminea var. longidentata
    7. ^ "World Checklist of Selected Plant Families: Royal Botanic Gardens, Kew". apps.kew.org. Retrieved 2017-01-31.

Distribution

    Distribution
    provided by eFloras
    Throughout the Old World.
    Distribution
    provided by eFloras
    Distribution: Tropics of Africa, Asia and Australia. Introduced into some parts of Europe (Italy, Romania & Bulgaria) and North America.
    Distribution
    provided by eFloras
    introduced; Calif.; Eurasia; Africa; Australia.

Morphology

    Comments
    provided by eFloras
    Because of the deeply auriculate sheaths, Najas graminea is one of the easiest of the North American and Central American Najas to recognize. Najas graminea often becomes weedy in rice fields of southeast Asia.
    Description
    provided by eFloras
    Stem up to 35-40 cm long and upto 0.7 mm thick, without spines; lower intemodes up to 10 cm long. Leaves linear, 10-40 x 0.5-1 mm, acute; with 2-3 teeth on the apex, flexible, minutely serrulate, c. 30 or more teeth on each margin, midrib without spines. Sheath wider than the laminae, prolonged on each side, narrowly triangular or deeply auriculate with 8-15 teeth on each side. Flowers without spathe, 1-2 per axil, staminate in the upper axil. Male flowers: 2-3 mm long, anther 4-thecous. Female flower: style with 2-3 stigmas. Fruits oblong-ellipsoid to subcylindric, 1.75-2.25 mm long. Amok irregular in shape and size, quadragular, rectangular to hexagonal.
    Description
    provided by eFloras
    Stems sparingly branched distally, to 35 cm ´ 0.2--0.5 mm; internodes 0.4--1.9 cm, without prickles. Leaves spreading to ascending with age, 0.8--2 cm, lax in age; sheath 1--1.5 mm wide, apex deeply auriculate; blade 0.5--1 mm wide, margins minutely serrulate, teeth 40 per side, apex acute with 2--3 teeth, teeth unicellular; midvein without prickles abaxially. Flowers 1--2 per axil, staminate and pistillate on same plants. Staminate flowers in distal axils, 2--3 mm; involucre beaks 4-lobed, 1--1.5 mm; anther 4-loculed, 1.5 mm. Pistillate flowers distal to proximal, to 3.5 mm; styles to 1 mm; stigmas 2-lobed. Seeds not recurved, greenish brown, fusiform, 1.7--2.5 ´ 0.4--6 mm, apex with style situated at center; testa dull, 3 cell layers thick, pitted; aeroleareoles regularly arranged in 35 longitudinal rows, not ladderlike, 4-angled, as long aser than broad, end walls slightly raised. 2n = 24, 36, 48 (Asia).
    Elevation Range
    provided by eFloras
    300-2300 m

Habitat

Cyclicity