I really should look down more often. I mean to say: how could I never have noticed before the miniature forest landscape that is Common liverwort (Marchantia polymorpha)?
According to the Naturespot website, the ‘umbrella-like reproductive structures [are] known as gametophores. Those of female plants consist of a stalk with star-like rays at the top. These contain the organs which produce the ova. Male gametophores are topped by a flattened disc and produce the sperm.’