This species has been renamed several times, with some sources listing it as belonging to genus Panacria. For the time being, however, I shall continue to refer to it as Prosthechea.
Prosthechea prismatocarpa came into my collection at Christmas 2016. Having seen mother plants blooming profusely at Burnham Nurseries earlier that year, I was delighted to hear that they had divided the latter and jumped at the chance of adding one to my collection.
According to several sources, this species is a cool to cold grower from the cloud forests of Costa Rica and Panama, and so, as I grow at warmer temperatures, it was with some trepidation that I decided to invest. It has grown well in my warm conditions, with excellent root growth. The only difference I can see by growing it warm is that it blooms significantly earlier than do those at Burnham Nurseries (early May, as opposed to July/August). The new pseudobulbs produced in my care have been shorter and fatter than those it had previously, but I put this down to differing light levels. Leaves are long and strap-like, and rather thick for a species of Prosthechea. It is rather a large plant and not as amenable to houseplant culture as P. cochleata or similar taxa. My plant already occupies a 20cm pot and has only just reached flowering size. Add to this the rather wide spacing of the pseudobulbs, and it is easy to understand why it isn’t more widely grown.
Having said all that, when it blooms, it is simply magnificent. The flowers appear from the top of the newly completed pseudobulb, as is usual with Prosthechea. Individual flowers are only a couple of centimeters across, but there are about thirty flowers per spike, which all open together and are really very eye-catching. They are reported to be fragrant, but I couldn’t detect any scent from my plant. Blooms are very long-lasting, and the last of them persisted until early July.