- In good conditions,the weed can germinate ,flower and set seeds within four weeks.
- Parthenium is insensitive to photoperiod as well as temperature variations.
- Parthenin is the major sesquiterpene lactone present in Parthenium growing wild in
India, in some races of the weed growing in Mexico, Parthenin is replaced by its
diaseriomer.
- In India, Parthenium was first observed in Poona in 1955.
- Parthenium posses some activity as a depressent to the central nervous system.
- Parthenium is reported to be responsible for largest number airborne contact dermatitis
in India. Almost every part of the Parthenium except root, is reactive.
- Parthenin an incomplete antigen hepatin in presence of sunlight (ultraviolet rays)
combines with albumin in the dermal part f the skin, becomes complete antigen and causes
photosensitive reaction.This is known as photophytodermatitis.
- Consumption of milk from the Parthenium fed livestock could be hazardous to man.
- The occurence of this weed in grassland is reported to reduce forage production upto 90
per cent besides making the land less fertile.
- Parthenium produces an average of 624 million pollens per plant.
- Large plants can produce more than 25,000 seeds which can be distributed by floating on
water or in mud adhering to animals, vehicles and machinery.
- Most of the Parthenium seeds germinate within two years if conditions are suitable,
although a portion of buried seed may remain viable for several years.
- In Australia, Parthenium is a serious problem in perennial grasslands in central
Queensland where it can reduce beef production by as much as A$16.95 million annually.
WHY PARTHENIUM IS NAMED AS PARTHENIUM ?
Parthenium is derived from the Latin word parthenice -a reference to the plant now known
as Tanacetum parthenium (L.)Bern. or Feverfew;hysterophorus is derived from the Greek
hystera (womb) and phorus (bearing) referring to the prolific seeding habit of the
plant.[Source:Navie,S.C.,McFadyen,R.E.,Panetta,F.D. and Adkins,S.W.(1996).The Biology of
Australian Weeds 27.Parthenium hysterophorus L.Plant Protection Quaterly 11(2):75-88.]
Parthenium is also known as Carrot weed (Eng.) or Gajar ghas(Hindi).The reason is that the
Parthenium leaves are alternate,sessile,irregularly dissected and bipinnate,resembling
that of Carrot(Gajar) or Chrysanthemum. Parthenium is also known as White Top,Safed
Topi(Hindi;Safed-white;Topi-cap) and Chatak
chandani(Hindi;Chatak-Bright;Chandani-moonlight) because of its numerous white flowers.
PARTHENIUM HYSTEROPHORUS - BOTANICAL DESCRIPTION
Parthenium is an annual, erect and diffusely branched herb.Its height varies between
50-100 cm. generally.Stems longitudinally grooved and covered with whtie
hairs.Leaves deeply 1-2 pinnately disserted .The size of leaves varies(2-10 x 3-5
cm.).Heads 5 mm. in diameter.Involucral bracts 2-seriate ;outer bracts 3.5 mm long;inner
bracts 3 mm long;thinner ,subtending .Ray florets 4 mm. long ,urceolate with
indistinct lobes ,membranous;disc florets 3.5 mm long;infundibuliform ;5-lobed;Achenes 2
mm.long ,obovate,black crowned with remnant of corolla appendages and style. [Source: Flora of Madhya Pradesh , Vol.I (Eds. D. M. Verma, N. P.
Balakrishnan and R. D. Dixit) Botanical Survey of India, India]
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