I recently purchased a plant which the grower referred to as Blechnum gibbum, or dwarf tree fern. I have searched many databases including the BBC, IPNI, and fern societies. Ultimately, I would like to discern the accurate, current name for the plant and plant culture and care information for in-home.
I confirmed the name Blechnum gibbum on the Royal Horticultural Society’s website, as well as in Sue Olsen’s Encyclopedia of Garden Ferns (Timber Press, 2007). For now you can safely assume that Blechnum gibbum is the correct, current name for the plant commonly called dwarf tree fern. It is a member of the family Blechnaceae, native to Fiji, and commonly grown as a houseplant in North America.
According to The New Houseplant Expert by D.G. Hessayon (Sterling, 1991), tree ferns require a temperature range between 60 and 70 degrees Fahrenheit (over 75 is a problem), an east or north facing window (or some shade in a hotter exposure), moist air (misting ferns can help with this), regular watering (particularly in spring and summer), and repotting so that the crown is not buried and the pot is not overly full of roots. The House Plant Encyclopedia by Ingrid Jantra (Firefly Press, 1997) says much the same thing, adding that temperatures below 54 are also a problem and that a light feeding once a month is helpful.