| Class: | angiosperms |
| Order: | Alismatales |
| Family: | Najadaceae |
| Genus: | Najas |
| Scientific name: | Najas marina L. |
| Name acc. to: | Gubanov 1996 |
| Herbar: | list records  |
| Synonym: | N. Major All. (acc. to Gubanov) (acc. to Grubov 1982) |
| Description: | Dioeciously aquatic plant 10-60 cm long; stem and leaves studded with sparse spines. Leaves linear acute-dentate, 1.5-4 x 0.2-0.4 mm, in verticils by 3, sessile, with sheathing base. Flowers solitary in leaf axils, unisexual small green. Fruit elliptic 2.5-8 x 1.5-4.5 mm. |
| Confuse with: | The accepted classification of the species in subsp marina and subsp. intermedia with numerous synonyms is cited in Wisskirchen 1998. We have seen 2 mongolian sheets determined as N. marina subsp. intermedia (Gorski)Casper. |
| Comments: | Najas is a large hydrophilous genera distinguished from Potamogetonaceae in its linear (opposite or whorled) leaves and unisexual sessile axillary flowers with 1 carpel. |
| Link to Flora of China: | http://www.efloras.org/browse.aspx?flora_id=2&name_str=Najas+marina |
| open map in a new window |  |
| Habitat: | Lakes channels and old river beds |
| Habit (i)general appearance of a plant | |
| Growth form: (i)Herb, shrub, tree or climber. | annual (i)Completing its life cycle within one year or one growing season; roots weak and thin
herb (i)Herbaceous, erect plant, up to 2m high, mostly with a leafy shoot; if perennial, shoots die to the ground each season, shoots are not woody
example: Artemisia pectinata   inherited by family Najadaceae: herb
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| Parasite status: (i)Is the plant a half- or full parasite? | no parasite/saprophyte (i)Plant fully autonomous, leaves with chlorophyll
example: Most plants, Ranunculus inherited by family Najadaceae: no parasite/saprophyte
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| Water or terrestrial plant: (i)Where do the plants grow? | water or swamp plant inherited by family Najadaceae: water or swamp plant
aquatic, submerged (i)Completely submerged water plant, onlys flowers may appear at the surface
example: Zannichellia inherited by family Najadaceae: aquatic, submerged
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| Leaf (i)expanded, usually photosynthetic organ of a plant (including phylloclades) | |
| Leaf development: (i)Structure and development of leaves. | flattened blade (i)Cross-section of lamina flat, plain inherited by family Najadaceae: flattened blade
common leaf (i)Green, often divided in blade and petiole
example: Cotoneaster inherited by family Najadaceae: common leaf
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| Leaf arrangement: (i)Arrangement of leaves at the stem. | whorled or fascicled (i)Three or more leaves per node or leaves crowded.
example: Galium, Nitraria  inherited by family Najadaceae: whorled or fascicled
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| Simple or divided leaves: (i)Are the leaves simple or completely divided in several parts? Blade of the leaf entire or (more or less) deeply dissected. Attention: There are various appearances of the leaf margin (from entire to toothed and lobed). Here, we ignore this and ask only for dissections that separate the leaf for more than one third of its length or width, whatever is smaller. Sometimes, it is difficult to tell apart compound leaves from a shoot system with simple leaves: look for stipulae and/or axillary buds at the ground of the leaves: if only some possess these structures, the others are most likely leaflets of a compound leaf. | simple (i)Non-divided leaf, but margin may be incised nearly to the ground  inherited by family Najadaceae: simple
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| Shape of blade: (i)Easy for simple leaves. In compound leaves use the general shape of leaflet. Always check the ground for largest leaves of a plant. To be worked out: how to handle pinnate leaves? | elliptic (including ovate and obovate) (i)Elliptic: broadest at the middle and narrower at the two equal ends; ovate: egg-shaped, attached at the broad end; obovate: attached at the narrower end
example: Limosella aquatica  inherited by family Najadaceae: elliptic (including ovate and obovate)
linear incl.grasslike or oblong (i)Leaves more than two times longer than broad with more or less parallel margins; see character: stipule for ligula
example: Dracocephalum ruyschiana, Poaceae, Scutellaria scordifolia, Pinus  inherited by family Najadaceae: linear incl.grasslike or oblong
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| Length of leaves: (i)How long is the leaf, be carefull in compound leaves, measure the complete leaf. | from 11 mm to 20 mm inherited by family Najadaceae:
from 21 mm to 50 mm inherited by family Najadaceae:
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| Leaf margin: (i)Structure of leaf margin (or that of a leaflet in case of compound leaves). Attention: Here we ask for the leaf margin, defined as all those dissections that separate the leaf for less than one third of its length or width, whatever is smaller. To be worked out: how to handle margin of pinnate leaves? | serrate / dentate / crenulate (i)Margin saw-like or rounded teethed
example: Betula, Lophanthus (crenulate)  inherited by family Najadaceae: serrate / dentate / crenulate
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| Petiole: (i)Leaf divided into stalk (petiole) and blade. | without (i)Leaves without petiole (stalk), sessile
example: Poaceae, Iris  inherited by family Najadaceae: without
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| Stipule: (i)Leaflets at the base of the petiole, these are smaller and of different shape. | none (i)Without stipules
example: Euphorbia, Ericaceae s.l. inherited by family Najadaceae: none
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| Flower (i)reproductive portion of the plant, consisting of sepals, petals, stamens, and pistils | |
| Flower appearance and pollination: (i)General appearance of the flower. | not attractive, wind-pollinated or some water plants (i)Small, colourless or green flowers
example: Betula, grasslike plants: Carex, Setaria, Juncus inherited by family Najadaceae: not attractive, wind-pollinated or some water plants
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| Perianth arrangement: (i)Attention: in some plants, flowers may be dimorphic in different ways (dioecious or gynodioecious). If flowers vary, record the characters of the most showy flowers. | absent or strongly reduced (i)No perianth leaves ensheathing stamen and/or carpels
example: Callitriche  inherited by family Najadaceae: absent or strongly reduced
simple, similar (i)Only one type of perianth leaves (tepals)
example: Tulipa  inherited by family Najadaceae: simple, similar
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| Stamen number: (i)Attention: We ask for the reproductive organs of the flower dispersing pollen. Count only fully fertile stamens, not staminodia (e.g. Parnassia). | 1 (i)
example: Orchis inherited by family Najadaceae: 1
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| Stamen fusion: (i)To which degree are the stamens fused? Attention: Whereas the pollen sacs itself are often free., their stalks (filaments) may be fused. Here, we count them as fused if they are together over at least one thirth of their length. | free (i)Stamens with separate bases
example: Malus inherited by family Najadaceae: free
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| Pistil number: (i)Number of pistils (female floral organs: style, if developed; stigma and carpels/ovary together build the pistil). | 1 (i)One carpel, but clearly one stigma
example: Pyrola, Primula, Alyssum inherited by family Najadaceae: 1
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| Carpel fusion: (i)To which degree are the carpels (modified leaf forming simple pistil or part of a compound pistil) fused. | fused (i)Carpels united into an ovary, only styles are free
example: Malus, Berberis inherited by family Najadaceae: fused
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| Style number: (i)Portion of the pistil connecting the stigma to the ovary. | 1 inherited by family Najadaceae: 1
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| Stigma number per style: (i)Number of stigmas per style. | > 3 (i)More than three stigmas, resulting from more than three fused carpels with or without develped style inherited by family Najadaceae: > 3
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| Sex: (i)Distribution of male and female organs among flowers, only most commonly cases. | unisexual (i)
example: Rhodiola inherited by family Najadaceae: unisexual
dioecious (i)Male and female flowers at different individuals
example: Antennaria inherited by family Najadaceae: dioecious
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| Inflorescence (i)flowering part of a plant, describes the arrangement of the flowers on the flowering axis | |
| Inflorescence: (i)Structure of the inflorescence. | Solitary flowers (i)Each flower grows on an own leafy stem there may be more than one, if the plant has many leafy shoots
example: Viola, Saxifraga hirculus, Rubus arcticus inherited by family Najadaceae: Solitary flowers
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| Fruit (i)the seed bearing organ, with or without adnate parts; a ripened ovary and any other structures which are attached and ripen with it. Aggregate fruits are handled like simple fruits for determination. | |
| Consistency: (i)Fleshy fruits or dry fruits, see dispersal adaptations for further classification. | dry (i)With a dry outer shell, no fleshy parts, but seed (embryo) could be edible inherited by family Najadaceae: dry
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| Type of fruit: (i)Common fruit types (including pseudocarp). | Indehiscent fruits inherited by family Najadaceae: Indehiscent fruits
Solitary fruits (i)    inherited by family Najadaceae: Solitary fruits
nut or nutlet (i)Dry fruit with a single, hard stone inside (and usually a large often edible embryo)  inherited by family Najadaceae: nut or nutlet
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| Opening of fruit: (i)Mode of dehiscence at maturity to release seeds. | not opening / indehiscent (i)Fruits remain closed at maturity and disperse with seeds inside
example: Corylus (nut), Vaccinium (berry) inherited by family Najadaceae: not opening / indehiscent
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| Size of fruit: (i)Size of the fruit including appendage. | from 5 mm to 10 mm (i)
example: Silene: small capsule opening with teeth inherited by family Najadaceae:
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| Dispersal: (i)Appearance of fruit or seed (if single) and adaptations to dispersal. | Otherwise (i)All parts dry, no conspicuous adaptations inherited by family Najadaceae: Otherwise
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| Seed number: (i)Estimate the number of seeds per fruit, if recognizable seeds are in the fruit (in rare cases a fruit may contain one seeded nuts: rose hip, carex). | 1 (i)A single seed (stone) or seed and fruit wall tightly connected
example: Prunus, Amygdalus: drupe inherited by family Najadaceae: 1
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| Root / shoot below ground (i)plant part below ground (in most cases), including below ground shoots, without leaves | |
| Root type: (i)Organisation of the roots. | homorhizous (i)Many equal roots
example: Monocotyledonae inherited by order Alismatales: homorhizous
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| Distribution (i)region where the plant is likely to be found | |
| Distribution (Veg. Zones): (i)acc. to Grubov 1952 | Depression of Great Lakes (i)In distribution data often named as '10' 
acc. to: Gubanov 1996 |