Update March 2023: After personal discussion with Dr. Michael Barfuss he has assured me that this is a species in its own right. So now the name reverts to Tillandsia vanhyningii. Update December 2022: This blog post was posted in July 2022. At that time the name change had been accepted for more than six months by the authorities who maintain the Bromeliad Taxon list of current names (http://bromeliad.nl/taxonlist/?), and Tillandsia vanhyningii was on that list. In October 2022, those same authorities decided that this variety should not have be elevated to species level, and the name reverted to Tillandsia ionantha var. vanhyningii.
Someone got promoted to SPECIES status! Tillandsia ionantha var. vanhyningii was first described by Mulford B. Foster in 1957. Foster discovered the now Tillandsia vanyningii (pronounced van-HIGH-nin-gee-eye) in the Sumidero Canyon of Chiapas, Mexico, growing along steep limestone cliffs in large formations. At first glance, Foster was sure it was a new species, but after blooming and observing the plant, it appeared they have the same composition as many other forms of ionantha. In a paper published last year, Carlos Beutelspacher and Roberto Garcia Martinez argued for the reclassification of Tillandsia ionantha var. vanhyningii by elevating it to species status due to the caulescent growth habit not observed in other varieties or cultivars of ionantha. The name change was accepted, and so Tillandsia vanyningii is born. The name, which can be difficult to say honors long time Tillandsia collectors, the Van Hynings.