Stephen, I would luckily welcome such weed in my garden/on our property. Great sight !
The single flowers of Onc. Sphacelatum are pretty small but the abundace of them on a flower spike makes it to a feast for the eyes.
Wow!!! Tropical beauty, and I bet not too much to worry about. They Just can live without much care. In my garden I have onc. Flexuosum, dend. Kingianum, laelia gouldiana, laelia superbiens, laelia speciosa and dend. Thyrsiflorum.