Cuscuta spp. - Love vine
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DESCRIPTION: FLOWERS: HABITAT:
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OTHER INFORMATION: Most plants are producers because they have chlorophyll and produce their own food. A few, like dodder are consumers in the sense that they derive food from sources other than photosynthesis. Indian pipe also has no chlorophyll and feeds on dead plant material, but dodder is a parasite of living plants, gaining not just water and minerals (as in some mistletoe) but actual carbohydrates. Each year it produces seeds that fall to the ground and germinate in the soil. The young dodder is a 2-4 inch long threadlike plant which grows to locate its host, then the tiny root system eventually dies once the plant is firmly attached to the host. The stem sends out suckers which gives the plant its nourishment from the host this way. Sometimes plastic-looking spaghetti-like masses form that totally obsure the host plant. These stems, lacking chlorophyll, are generally yellowish-to-reddish, but sometimes are even white. Then in late summer and fall the plant produces numerous tiny white flowers. These flowers produce the 2-celled fruit capsules which burst open to release 1 to 4 seeds, which is the only way the plant reestablishes itself each year. It's interesting how dodder works. Dodder seedlings must attach to a suitable host within a few days of germinating or they die. The young seedling is sensitive to touch and the stem gropes in the air until it makes contact with a plant. The contact is made firm by one or more coils around the stem. If this plant happens to contain foods suitable to the dodder then a secondary stimulus is aroused which causes root-like branches to form (called haustoria, from Latin - haurire, to drink and are evolved from, or modified roots) which penetrate the stem. The part of the plant connected to the root system soon shrivels away so that no soil connection exists afterward. Because it twines around its host plant and has flowers, it's also called "Love vine." Other names for different species (some forming large masses) include local names such as: strangleweed, devil's-guts, goldthread, pull-down, devil's-ringlet, hellbine, hairweed, and devil's-hair. I guess the plants strange look and the fact that it feeds off of some crop plants are, i'm sure, part of the reason it is named so evilly. Dodders lack chlorophyll since they've evolved to gain sustenance from their host plant, but some studies have shown that they may contain some chlorophyll in the buds, fruits and stems. In fact, intact plants when grown on sterile, solid mineral cultures and under low light intensities, developed both chlorophyll a and b. Those plants were difficult to maintain for long periods of time however. Chlorophyll degradation occurred rapidly under full sunlight. It would appear that the amount of food manufactured in these tissues is of little significance to the survival of the plant Dodder attacks a wide variety of hosts, wild and cultivated. It is considered an intolerable pest to crops such as alfalfa, onion, flax, clover, peas, beans, potatoes and many more. It is particularly troublesome where alfalfa, clover and onion are grown for seed because dodder seed is difficult to remove from the rest of the seed crop and thus passed to next year's crops. Dodder seeds can also be spread by irrigation water and in the manures of livestock that have eaten infested hosts, like alfalfa. Apparently dodder seeds can last up to at least 5 years, dormant, waiting for the right conditions. Gardeners can find dodder attacking ornamentals such as chrysanthemum, dahlia, helenium, Virginia-creeper, trumpet-vine, English ivy and petunias. If you find dodder invading your garden, it's best to destroy it along with its host plant, because it rarely can be removed without severe destruction anyway. Removal, especially those that form large masses, thru chemical means are not only limited, but nasty to use and sometimes destructive to the plants they're intended to save. The best removal should be done as early in the season as dodder is discovered, before it goes to seed. If the infested area is a new garden area, start looking for more infestations each year for at least 5 years. There is some evidence that dodders are capable of spreading viral diseases from one host to another. Phytoplasma, the cause of more than 200 so-called yellows diseases (previously thought to be caused by virus) are spread by dodder and other means such as leafhoppers. Dodder has been shown to spread the yellows disease pear decline, aster yellows, tomato big bud, vinca virescence and elm phloem necrosis. Also, certain destructive bacteria have been found to be present in dodder. In the wild, dodder probably doesn't get out of hand because it doesn't have a decent means of seed transport except in those species that infect the plants which are eaten by deer (and the seed passed on to the next group). There are several species of dodder in the area, each difficult to distinguish, but some have specific 'preferred' hosts. Besides the human crops mentioned above, there are quite a number of native plant hosts such as goldenrods, smartweed and the pictured jewelweed. This list includes even some of the more woody-stemmed plants such as blackberry and reportedly some trees, but i haven't found which species. MEDICINAL USE: Now that i've painted a picture of strangling parasitism for this pretty waxy-flowered plant brother, let's see if it has a helpful side. American Indians seems to have harvested the plant while it was in flower, taking the whole plant. They used the plants in a bath for the treatment of tuberculosis. Early settlers, probably taking cues from the natives, put fevered children in a similar bath. It's unclear if this did much good. Indians also thought the plant a useful contraceptive, but i'm not sure used exactly how... topically or internally or what. A poultice made from the entire plant has been used to treat bruises and insect stings. Also it has been used as a bile stimulant and a laxative. Chinese people have been observed gathering the seeds which they used as an eye wash or as a tea for urinary tract problems and one Chinese species has demonstrated anti-inflamatory, cholinergic and CNS depressant activity. Note: Even though dodder is frequently called 'vegetable spaghetti' in literature, it earned that name because of the way it looks and it is not generally considered edible. ONE LAST INSULT: Interestingly, according to the USA Bride Magazine's Flowers and their Meanings, the meaning of the dodder that parasites thyme once offered as a gift indicates "Baseness." Plants in the family as a whole (Cuscuta) indicate "Meanness." All of which doesn't bode well for the already pursued dodder as a destroyer of crops, bane to the gardener, and witchy mass of weirdness to the casual woods-walker. LIST OF KNOWN AMERICAN DODDERS: (I'm unsure which are local and native to
WNC)
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OFFSITE INFORMATION:
If you're interested in Dodder or parasitic plants in general, the place to go is Southern Illinois University's The Parasitic Plant Connection. Dodder and related species has
Many pictures of dodder (and one of smartweed dodder) can be found at the Plant Image Gallery of Texas' A&M University.
Information on the family Cuscutaea is at the Families of Flowering Plants. Also, several photos.
Even the Aussies aren't 'free' of their own parasitic dodder. See the Australian National Botanic Garden's info on this family.
Finland's FUNET has some pictures of the european version.
A discussion (and photo) of Dodder as a parasite is described in the Colorado State University Cooperative Extension webpage.
The UCLA Life Sciences Division webpage has an interesting picture of the California dodder completely obscuring the host plant.
