[5] Rhizomes very rarely prostrate, usually erect, forming a woody trunk up to 12 metres (39 ft) tall, 160 to 450 millimetres (6.3 to 17.7 in) in diameter, covered in light brown or white projecting stipe bases, bearing scales near the apex.Evidence of large amount of macro-charcoals in the top layers of soil suggest that Cyathea dealbata establish themselves in areas where anthropogenic fires occur The earliest use of the silver fern as an official emblem was by the New Zealand Army during the Second Boer War.New Zealand peacekeepers have since used both the silver fern and kiwi symbols for different deployments to differentiate from their Australian and British counterparts.[citation needed] Additionally, several British Army units wear the silver fern, normally as a battle honour granted for serving with New Zealand troops.[18] In 1991, the New Zealand Rugby Football Union obtained trade marks for the name “All Blacks” and its own stylised fern, however the scope of the application was broader because they sought to register any 'fern'.In 2005, after a legal case lasting four years, the union failed in its bid to stop anyone else using any fern logo on any black jersey.