| Class: | angiosperms |
| Order: | Alismatales |
| Family: | Najadaceae |
| Editor | S. Rilke, June 2009 |
| Name acc. to: | APweb |
| Herbar: | list records  |
| Description: | Aquatic submerged plants with slender, much branched stems. Leaves oblong, with sheathing base, margin dentate to toothed, crowded in leaf axils (in verticils by 3, rarely opposite). Flowers reduced unisexual, pollination takes place underwater |
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| genus: 1 |
| species: 1 |
| Habit (i)general appearance of a plant | |
| Growth form: (i)Herb, shrub, tree or climber. | 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 
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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
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| Water or terrestrial plant: (i)Where do the plants grow? | water or swamp plant
aquatic, submerged (i)Completely submerged water plant, onlys flowers may appear at the surface
example: Zannichellia
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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
common leaf (i)Green, often divided in blade and petiole
example: Cotoneaster
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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 
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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 
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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 
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 
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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
from 21 mm to 50 mm
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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) 
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| Petiole: (i)Leaf divided into stalk (petiole) and blade. | without (i)Leaves without petiole (stalk), sessile
example: Poaceae, Iris 
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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.
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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
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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 
simple, similar (i)Only one type of perianth leaves (tepals)
example: Tulipa 
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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
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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
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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
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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
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| Style number: (i)Portion of the pistil connecting the stigma to the ovary. | 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
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| Sex: (i)Distribution of male and female organs among flowers, only most commonly cases. | unisexual (i)
example: Rhodiola
dioecious (i)Male and female flowers at different individuals
example: Antennaria
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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
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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
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| Type of fruit: (i)Common fruit types (including pseudocarp). | Indehiscent fruits
Solitary fruits (i)   
nut or nutlet (i)Dry fruit with a single, hard stone inside (and usually a large often edible embryo) 
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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)
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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
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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
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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
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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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