Pando trumped - new world's largest plant

A single clone of seagrass has been found covering an (inferred) area of approaching 200 km2, which beats Pando’s 43 acres hands down. I wondering how it compares with the Humongous Fungus.

The distribution is discontinous, which is in opposition to the headlines’ “largest plant on earth”. (I saw a claim a few weeks back of Narcissus ‘Carlton’ as the world’s most massive organism, but few people would treat clonally propagated cultivars as single individuals.)