The solitary Gomphocarpus cancellatus fruit near the leafy stem-tip in picture raises the issue of a low fruit production rate from what is usually a large stem-tip flower cluster. This fruit will make up some of what has been lost by releasing numerous seeds in due course.
The fruit tapers to an about truncate tip that curves, in this case towards the stem. Faint, short hairiness is white and downy, present on all plant parts in view, although not everywhere evenly applied (Manning, 2007; Bean and Johns, 2005; iNaturalist).