The hefty fine is in place to protect a rare plant only found in the park, near Castlemaine.

Ballantinia antipode, more commonly known as Southern Shepherds Purse, was thought to be extinct until it was rediscovered in the park in 1983.

The small annual native plant grows on moist moss mats attached to granite rock surfaces and can be identified by minuscule white flowers on its upper stems.

Parks Victoria and the Department of Human Services are concerned some mountain bike riders in the area have been creating new trails down granite rock surfaces, destroying the rare plant.

As a result Parks Victoria and DSE have increased their protection measures and are conducting more ranger patrols and increasing surveillance in the area.

Parks Victoria ranger in charge of Northern Goldfields David Major said most mountain bike riders in the Park did the right thing and stayed on the tracks.

“We have a great relationship with the Central Victorian Mountain Bike Association and have worked with its members to educate them about the plant and how their activities can adversely affect it,” Mr Major said.

“However, it takes just a few thoughtless riders to destroy this endangered plant and wipe it off the face of the planet.”

DSE threatened species project officer Terri Williams said the Southern Shepherds Purse was protected by law.

She said anyone who destroyed the plant or had a significant impact on it faced fines of up to $55,000.

“Mount Alexander Regional Park is the last place on earth this beautiful plant exists,” she said.

“We encourage riders to use the tracks at Mount Tarrengower instead and leave this rare flora alone.”