Some members of the
Chrysanthemum genus, such as the following two, are placed in the
Tanacetum genus instead by some botanists. Both genera are members of the daisy (or aster) family,
Asteraceae. They are all
perennial plants with a daisy-like appearance and
white petals.
-
Tanacetum cinerariifolium
T. cinerariifolium is called the Dalmatian chrysanthemum, denoting its origin in that region of the Balkans (Dalmatia). It looks more like the common daisy than other pyrethrums. Its flowers, typically white with a yellow center, grow from numerous fairly rigid stems. Plants have blue-green leaves and grow to 45 to 100 cm in height. The plant is economically important as a natural source of insecticide. The flowers are pulverized and the active components, called pyrethrins, contained in the seed cases, are extracted and sold in the form of an oleoresin. This is applied as a suspension in water or oil, or as a powder. Pyrethrins attack the nervous systems of all insects, and inhibit female mosquitoes from biting. When present in amounts less than those fatal to insects, they still appear to have an insect repellent effect. They are harmful to fish, but are far less toxic to mammals and birds than many synthetic insecticides and are not persistent, being biodegradable and also decompose easily on exposure to light. They are considered to be amongst the safest insecticides for use around food. Kenya produced 90% (over 6,000 tonnes) of the world's pyrethrum in 1998, called py for short. Production in Tanzania and Ecuador is also significant. Currently the worlds major producer is Tasmania, Australia.
-
Tanacetum coccineum
C. coccineum, the Persian chrysanthemum, is a perennial plant native to Caucasus and looks somewhat like a daisy. It produces large white, pink or red flowers. The leaves resemble those of ferns, and the plant grows to between 30 and 60 cm in height. The flowering period is June to July in temperate climates (Northern Hemisphere). C. coccineum also contains insecticidal pyrethrum substances, but it is a poor source compared to C. cinerariifolium.
- Other species, such as C. balsamita and C. marshalli, also contain insecticidal substances, but are less effective than the two species mentioned above.
Tanacetum cinerariifolium
[h=2][
edit] Insecticides[/h][h=3][
edit] Sprays[/h]Pyrethrum was used for centuries as an
insecticide,[SUP]
[1][/SUP] and as a lice remedy in the
Middle East (
Persian powder, also known as "Persian pellitory"). It was sold worldwide under the brand
Zacherlin by Austrian industrialist
J. Zacherl.[SUP]
[2][/SUP]
The flowers should be dried and then crushed and mixed with water. Though the pesticide is natural, it can still be harmful to humans.[SUP]
[3][/SUP]
- Pyrethroids are synthetic insecticides based on natural pyrethrum (pyrethrins); one common example is permethrin. A common formulation of pyrethrin is in preparations containing the synthetic chemical piperonyl butoxide: this has the effect of enhancing the toxicity to insects and speeding the effects when compared with pyrethrins used alone. These formulations are known as synergized pyrethrins.
[h=3][
edit] Companion planting[/h]
Because of the natural insecticidal properties of the pyrethrums, they are used as
companion plants, to repel pest insects from nearby crops and
ornamental plants.[SUP]
[4][/SUP] They are thought to repel
aphids,
bed bugs (
Cimex lectularius),
leafhoppers,
spider mites,
harlequin bugs,
ticks,
pickleworms and imported
cabbage worms, among others that are in gardens and farms. For example, they are planted among broccoli plants for protection from several common insect pests.
[h=2][
edit] Common names[/h]Common names for
Chrysanthemum cinerariifolium include:
- Pyrethrum
- Pyrethrum daisy
- Dalmatian pyrethrum
- Dalmatian chrysanthemum
- Dalmatian insect flower
- Dalmatian pellitory
- Big daisy
Common names for
Chrysanthemum coccineum include:
- Pyrethrum
- Pyrethrum daisy
- Painted daisy
- Persian chrysanthemum
- Persian insect flower
- Persian pellitory
- Caucasian insect powder plant
sorry for the lengthy explaination but it is good for outside gardeners and people with pets who grow and they should know their options.......from your good friend Bill Nye the Science guy aka PITTSBURGH