that was tricky ! I did a word-by-word comparison of the two species descriptions in Vic Flora. The only characters are number of stamens (3 or 6, and not available) and whether leaves are uni-tubular or multi-tubular (also not available). What swung it was the long-sharpness, the clustering, and the outer tepals in J. prismatocrpus are sometimes curved at tip. But ID could easily have gone the other way. I hadn't realised these two were so similar until this afternoon: descriptions are near identical. Happy to change if you think its J. prismatocarpus.