Events celebrating marijuana in the US this weekend are expected to draw tens of thousands as crowds test the limits of new laws permitting its use by adults.

More than 50,000 are expected to light up outdoors in Denver’s Civic Centre Park to celebrate marijuana legalisation.

Thousands more are going to a Cannabis Cup event at a convention centre, including Snoop Lion, the new reggae- and marijuana-loving persona for the rapper better known as Snoop Dogg.

Marijuana activists from New York to San Francisco consider April 20 a day to celebrate the drug and push for broader legalisation. (PA)

Bluebells are under threat

The next generation could struggle to see native bluebells in UK woodlands as hybrid varieties take over, experts have warned.

Carpets of scented native bluebells are one of the sights of spring but the plant has bred with the non-native Spanish bluebell, which was introduced to ornamental gardens more than a century ago. The native bluebell has dark blue scented flowers which grow on only one side of the stem, while hybrids have unscented lighter blue flowers on both sides of the stem.

Varieties of hybrid and Spanish bluebells can now be seen growing in woodlands alongside native blooms, and the Forestry Commission predicts the British bluebell could be overtaken by hybrids within a generation. (AP)

Thieves target Rhino heads

Four rhinoceros heads with eight horns worth about €500,000 have been stolen from museum storage in Ireland.

Three masked men broke into the National Museum Archives in Swords, north Dublin, and tied up a security man before the robbery, which lasted about an hour.

The rhino heads with horns had been taken off public display more than a year ago and put into storage after a spate of similar thefts from museums and private collections in Europe. (PA)

Dubai’s flashy police cars

Dubai police seem to have a liking for Italian speed: they are making preparations to have a £163,000 (€191,000) Ferrari join an even pricier Lamborghini as the flashy flagship of their fleet.

The two ultra-cars, sporting the green and white police colours, will patrol tourist zones in yet another expression of the city’s endless pursuit of glitz.

Next up? Police say they are working on converting the classic American muscle car Camaro model into a fleet of regular squad cars.

Last week Dubai police unveiled a £360,000 (€421,000) Lamborghini Aventador. (PA)