The Bladderworts
What are they?
The Bladderworts are an amazing group of plants who satisfy their need for nutrients, in an otherwise nutrient-poor environment, by trapping insects. They do this by means of bladder-like traps which may be found on the subaquatic, root-like stems of the plants.
Where are they found?
Bladderworts grow in wet bogs, either in very wet mud, or floating in open, usually acidic, water. Plants can be hard to find when not in flower.
Identification
Identification of Bladderworts is mostly based on the flowers, but can often be very difficult. The presence or absence of a spur at the back of the flower is important while leaf detail can also be useful.
Eastern Purple Bladderwort Utricularia purpurea
Uncommon in ponds and other more or less permanent wet areas, but where it occurs, it can be plentiful. Flowers July to September. Flowers light lavender pink.
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Lavender Bladderwort Utricularia resupinata
Uncommon in ponds and other more or less permanent wet areas, but where it occurs, it can be plentiful. Flowers June to September. Easily told from the other bladderworts by its pinkish-purple flowers which are half tipped back so that the spur stands out from the rest of the flower.
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Humped Bladderwort Utricularia gibba
Common in bogs and other permanent wetlands. Flowers June to September. Note conspicuous humps in the center of the flower and the relatively short, conical spur.
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Common Bladderwort Utricularia macrorhiza
Occasional in wet bogs and other permanent wetlands. Flowers June to September. Despite the name, ths is not a common species in the Cape May area. The flower looks rather flattened when viewed side-on and the spur on the back of the flower is strongly curved.
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Floating Bladderwort Utricularia radiata
Usually found in permanent open water, where the inflated leaf bases allow it to float at the surface. Flowers May to September. Best told by the inflated leaf bases; flowers with short, inconspicuous spur.
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bladders |
leaf bases |
Zigzag Bladderwort Utricularia subulata
Common in the northern half of the county. Flowers May to July. A tiny species that is almost always found on wet mud rather than in standing water. Flowers may be carried singly or widely-spaced on a zigzaging, thin and wiry stem. The spur is equal to, or slightly longer than, the lower petal and is usually carried hidden beneath it.
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Rush Bladderwort Utricularia juncea
(Southern Bladderwort) An uncommon species of sphagnum bogs and pond edges. Flowers July to September. Flowers rather small and well-spaced from each other on the flowering stem. Spur long and conspicuous. The lower flowers on the spike are often cleistogamous - they self-pollinate without opening, so always appear as though they are still in bud.
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Striped Bladderwort Utricularia striata
A widespread species of sphagnum bogs and pond edges. Flowers June to September. Flowers have a rather long, conical spur; submerged leaves in two forms - thrice-forked and twice-forked, with only the latter bearing traps.
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with traps |