P. williamsii is a medium-sized meconostigma plant with attractive glossy and entire leaves. This plant prefers growing in semi-shade or full shade - if grown in full sun, the leaves can burn or become yellow-green in color.
P. williamsii is not known very well in the trade, although for years plants were sold as "P. williamsii" when in fact they were P. stenolobum. When I did my original cross of P. bipinnatifidum (selloum) and P. stenolobum, I was under the belief that P. stenolobum was P. williamsii, so I named my hybrid "P. x willoum".
Below see detail of the stem of P. williamsii; you can also see tags indicating my hybrid work with the blooms.
Above see the bloom of P. williamsii.
And last but not least, the fruit produced by P. williamsii