Class: | angiosperms |
Order: | Alismatales |
Family: | Lemnaceae |
Name acc. to: | APweb |
Herbar: | list records |
Synonym: | Araceae (acc. to Heywood 2007) |
Description: | Small floating aquatic, pad-like plants, with leaflike struktures, mostly without flowers. With or without roots. |
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| genus: 2 |
| species: 4 |
Habit (i)general appearance of a plant | |
Size of plant: (i)Attention: use flowering or fruiting specimens to assess plant height (many biennial plants possess only a basal rosette in the first year). | to 100 mm
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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? | aquatic, leaves floating (i)Plant submerged in water, but leaves and flowers above surface example: Nuphar water or swamp plant
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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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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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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? | entire (i)Plain margin, not toothed example: Iris
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Leaf veination: (i)Arrangement of the main veins of a leaf. | parallel (i)Most veins arranged parallel to the length of leaf, mostly no pronounced main vein (usually in elongate to linear leaves) example: Most Monocotyledonae, Plantago, Veratrum, a lot of Caryophyllaceae looks like that.
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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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Diameter of flower: (i)Diameter of flower or flower head. | to 5 mm (i) example: Aruncus
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Spur: (i)A hollow, slender, sac-like appendage of the perianth leaves, storing nectar. | no spur (i)Flower without appendage example: Peganum
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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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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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Ovary position: (i)For entirely or partly fused carpels, describe their position in relation to the insertion point of perianth leaves (best done by doing a longitudinal section of a flower). | superior (hypogynous) (i)Base of carpels attached above insertion point of perianth leaves, carpels free or fused example: Delphinium, Anemone
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Sex: (i)Distribution of male and female organs among flowers, only most commonly cases. | bisexual, hermaphrodite (i)All or nearly all flowers of a plant with male and female parts example: Haplophyllum, Chenopodium
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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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