Nickernuts are a tropical plant that reaches the coastal areas of South Florida.
"Wild Florida" is a diary series that explores the flora and fauna of the Sunshine State.
The Nickernuts are a group of plants that belong to the legume family, making them relatives of peas, tamarind and peanuts. There are 12 species in the genus Guilandia, and six more in the large genus Caesalpinia that seem to be closely related (and some taxonomists have argued that these should be moved to Guilandia). Also known as Sea Beans or Nicker Beans, they are found mostly in the Caribbean islands, but because the seeds float readily and the beans can survive long periods in salt water, some of them have become widely spread throughout the tropical world.
The name “Nickernut” comes from the Dutch word nikker, which means “marbles”, and refers to the fact that these round marble-like seeds are often used in tropical areas as game pieces for the widespread African game Mancala. (I did a diary on Mancala here: www.dailykos.com/...) The plants are therefore known in many tropical areas as Warri or Owara (both are also names for local versions of Mancala). Nickernuts are also popular for making jewelry, as they are attractively-colored and can be easily strung to form necklaces or bracelets. This has led to the alternate name in some areas of “Sea Pearls”. The plants also contain a chemical similar to quinine, and they are used in some traditional medicines and known as “Fever Beans”.
Two species, both formerly in the Caesalpinia genus but now formally moved to Guilandia, are found in Florida, where they range from the Keys up to around Tampa Bay. G. bonduc, known as the Gray Nickernut, is the more widespread, while G. major is known as the Yellow Nickernut. Both are limited to the tropical and subtropical areas of South Florida, where they are often found along coastal dunes and mangrove forests.
Nickernuts most often grow as a climbing vine, draping itself over other vegetation. But in open areas it can also take the form of a spreading shrub or a small tree. The woody parts bear protective spines, while the long compound leaves are armed with thorns. Like most legumes, the roots have nodules that house bacteria which are capable of drawing nitrogen directly from the atmosphere and adding those nitrogen compounds to the soil.
The yellow flowers bloom in spikes. When fertilized, they form green clamshell-shaped seedpods, about three inches long, that are covered with spines. These turn brown as they mature, and when the seeds are ripe the pods split open. Each pod contains two seeds, each about the size of a glass marble. The immature seeds are green: in G. bonduc the mature seeds are shiny and gray, while in G. major they turn yellowish or brownish.
Florida Nickernut plants serve as hosts for the caterpillars of the rare and endangered Miami Blue and Nickerbean Blue Butterflies.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)