|P. callosum has strap-shaped gray green leaves, to 10 inches long, with dark green mottling. Blooms in spring, solitary, maroon and green flowers, with white striped maroon upper sepals and maroon lips.
Thick, broad, strap-shaped green leaves, often mottled with light grey-green. Orchid-shaped blooms with a distinctive pouch are borne singly. Prefers cool to intermediate temperature and ample moisture. Some species require night chilling. Mottle-leafed species require less chilling at night. High humidity preferred during summer months.