Microsorium musifolium Copel.
Microsorum musifolium

Crocodile Fern, Crocodylus Fern

 

Sold with the trade name  Microsorium 'Crocodylus'

Correctly Should be Listed as Microsorum musifolium (see text)

Formerly known as Polypodium musifolium 
   

Microsorum or Microsorium?  If you located this plant on many websites you may have been confused by the name spelling.  After a good deal of searching plant literature we've discovered (January, 2007) the correct genus spelling is "Microsorum".  With the assistance of the editors of the University of British Colombia plant web site (UBC) we were directed to the Australian Plant Names Index (APNI).  On that site a quote from a Mr. Bosman clarifies the conflict.  The genus Microsorum was originally published in 1833.  Botanist Dr. Link went on to publish papers in 1841 using both the spelling Microsorum and Microsorium (with an "i") in the same paper.  Since that time both spellings have been used by botanists to describe the same genus.  Since you can find both spellings on numerous scientific sites (TROPICOS, IPNI, ePIC and others) apparently either is acceptable.  But, in the purely technical sense, Microsorum is the correct genus spelling (first publication takes precedence).  Two separate genus do not exist.  In this instance, the International Plant Names Index (IPNI) uses only Microsorium musifolium so we have left the spelling as published.

On this site we are often hesitant to use the term "rare" when describing many plants.  A rare plant is one that is scarce in nature or somewhat difficult to obtain, not one you can buy on eBay for under $10 almost any day of the year.  When there is evidence a plant is rare we include a "Rare Plant" icon .  There are however a large number of formerly truly  "rare" plants that are now being tissue cultured (cloned) and which can be honestly called at least "semi-rare".  Sellers on the web, especially eBay, claim in bold letters Microsorium musifolium (mew-sih-FOH-lee-um)  or Microsorium 'Crocodylus' (as they love to call it), is rare.  Unusual, certainly.  Rare?  Maybe when it was wild in its native rainforest near Cairns, Australia or Papau New Guinea before it was commonly cloned.  But now?  Don't think so. 

 

And to top it off a noted "plant" website has been leading searchers to believe the name Microsorium 'Crocodylus' is truly a botanical name and the real name (Microsorum musifolium or Microsorium musifolium) is the synonym!  I think someone needs to send those folks a book on botany.  The first name the plant was published under is the accepted botanical name.  All future names that are published in scientific literature (in error) then become synonyms.  Trade names are never considered synonyms!  The name ‘Crocodylus' is a registered trade name given the plant by the company in Australia that first tissue cultured (cloned) the fern.   ‘Crocodylus'  is not part of the plant's actual scientific name and cannot be found in any botanical reference or source.   We have found similar errors on numerous other plants on that website. 

 

You can find Microsorium musifolium, the fern with fronds that are similar in appearance to a crocodile's skin, for sale effortlessly on a dozen websites.  Those "scales" are known scientifically as clathrate scales.  Some sources offer small plants for just a few dollars.  Rare?  No. New?  Hardly.  It is however a fabulously unusual fern (hardly new since it's been around since the planet was created) that is now commonly available.  This very unique fern has elongated strap-like blades which have the appearance of crocodile scales and is capable of producing a thick bushy plant.   Our friend Randy King of King Foliage in Homestead, FL introduced us to this unusual specimen.  Randy sent  an e-mail and told us one was on its way.  Easy to grow, this fern will soon outgrow a terrarium or vivarium with up to three foot fronds so consider it for a good size pot in the greenhouse or garden provided you live in a warm climate.  The plant prefers moderate to fairly bright light and high humidity but does not grow well if the roots are kept wet.  Avoid over watering!  

 

Microsorium musifolium is said by some to be a "hardy" fern whose fronds contain a labyrinth of darkly pigmented veins which become more conspicuous as the plant ages.  The fern grows from a rhizome and is capable of climbing.  The frond collects humus, has a thin blade texture,  and produces numerous small sori (spore cases) scattered all over the underside of the frond along the veins.  The plant is a native of Malaysia, the Philippines, Indonesia, New Guinea and a rainforest valley near Cairns, Australia and can be epiphytic (grows on trees). The fern was earlier known as Polypodium musifolium and most literature says the fern does not appreciate temperatures below 55 degrees.  Some websites say it is actually semi-tropical and can be grown in Zone 7A.  We live in 7B but I wouldn't risk loosing the plant just to find out if it is "hardy".  It can be grown in Southern Florida as a landscape plant in bright filtered light most of the year even though temps sometimes drop quite low.   Experienced South Florida growers recommend bringing it indoors for the coldest part of the winter.  Some large growers near King Nurseries in Homestead have reported major losses when the temperature drops too low in the Miami area making us question whether or not it will grow in Zone 7 or 8.

 

Once established, the plant can easily be divided or, if you are experienced in the collection of sori, grown from spores.  Our larger plant in the photograph came from Natural Selections Exotics in Fort Lauderdale.  You can find a link to their website on our links page which can be found at the bottom of the home page of this site.  King Nurseries is a wholesale grower.