A recent survey of the Himachal Pradesh Forest Department has pointed out that the deadly weed Lantana, called Phool Lakri in local parlance, has affected the mountain bio-diversity in more than 1,800 sq km of forest lands in the State.

The weed which is a flowering exotic shrub is now found in abundance in the State and is seriously threatening the natural regeneration of majority native plant species. Though there are also other weed species found in the hill State like Parthenium (Congress Grass), Ageratum (Neela Phoolnu) and Eupatorium but the invasive Lantana is proving to be the most lethal to the rich forest biodiversity of the region.

Lantana is a genus of about 100 species of perennial flowering plantsin the verbena family, Verbenaceae, said experts. Though native to tropical regions of the Americas and Africa, they now exist as introduced species in numerous areas of Asian and Australian Pacific regions. The genus includes both herbaceous plants and shrubs (found mainly in Himachal) growing as tall as five to six feet. Lantana’s aromatic flower clusters called umbels are a mix of red, orange, yellow, blue or white florets. ‘Wild lantanas’ are plants of theunrelated genus Abronia, usually called ‘sand-verbenas’.

Lantana was introduced in India in 1809 in the Indian Botanic Garden, Kolkata as an ornamental plant due to its beautiful aromatic flowers. Prolific seed production and easy dispersal helped it in escaping cultivation and becoming a pest, with serious dimensions. Present all over Himachal Pradesh, it flowers almost throughout the year. This weed is posing serious problems to plantation forestry as it chokes all other vegetation and becomes the dominant species. In deciduous forests, Lantana is considered as a potential fire hazard and it is combustible even when green. Himachal Pradesh struggles with forest fires every summer and suffers huge losses. This weed is also dangerous in national parks and sanctuaries.

Lantana also competes with agricultural crops and has an allelopathic effect — inhibiting the growth of other plants. The Himachal Pradesh government has faced failure in uprooting this enveloping weed which has now entered the fields and orchards of the farmers. The State is yet to have any comprehensive planning to eradicate this problem which has to be done in entirety and requires massive re-plantation of other friendly species like Bamboo, Acacia Catechu (khair) and Phyllanthus Emblica (amla).

The funds allotted by the Centre for the purpose are used in a piecemeal fashion through a campaign suggested by certain environmental NGOs like the Himachal Gyan Vigyan Samiti. The organisation had run a campaign in some panchayats and blocks of the State in the past and had even destroyed the lethal weed with the help of villagers in these areas, said O.P. Bhuraita, a scientist with the organisation. The Samiti had later shifted its focus to the menace of wild animals and monkeys in the countryside, since that has become a foremost threat to the agriculture and fruit growing areas, he said. Agriculture is the mainstay in the hill State and 90 per cent population lives in rural areas.

The previous State government had accepted that the weed species have spread to large areas of forest and wastelands, with the 1999-2000 survey revealing that 136,301 hectares were covered by weeds and Lantana alone had spread to over 130,000 hectares of land. For eradicating the Lantana, the Forest Department has used two methods: mechanical and chemical. Under the mechanical method, the weed is physically removed with tools like ‘monkey jack’. This labour-intensive method has shown good results. However, the chemical methods like spraying glyphosate have environmental andecological impact.

During 2009-2013, the weed has been removed from 6,305 hectares of forest land and the government has targeted to clear 5,000 hectares of forest land of Lantana weed during 2013-14, State Forest Minister Thakar Singh Bharmouri said. To root out Lantana, a cut-root stock method has been adopted. After clearing the weed, foliage fodder is being replanted, he said. The question as to how to eradicate Lantana and other weeds comes up every time here during the Assembly sessions, with precious little being done to help the small and marginal farmers who are forced to quit agriculture due to this problem.