In central and south Florida one Central American invader seen volunteering occasionally is Leadwood (Leucæna leucocephala), a tree whose leaves may be used as green manure.
Leadwood has several interestng properties, one being that the wood has a specific gravity that is greater than that of water so it sinks, hence the common name. It also, when the wood is dried, may be used as firewood and it burns hot (good for cooking or heatiing) but leaves no ash! Yet the live trees can also provide a decent firebreak.
The trees can be cut down each year and the fresh leaves turned under as a readily enriching green manure since they are high in nitrogen. (This is also true of comfrey, mentioned above in this thread.) And the trees will grow back rapidly so that by the following year they will be ready to cut for manure again.
Leadwood's leaves can successfully be used as cattle forage, just as is done n Central America, but the amount fed to the cattle must be limited due to an alkaloid contained in them which, if consumed to excess, causes the cattle's hair to fall out resulting in sunburned backs.
It is odd to me that so few people have taken advantage of Leucæna leucocephala for its various useful porperties. It apparently does self-sow here in Florida and seed can be collected from trees as they do have a distinct flowering season, producing large, distinctive heads of white flowers followed by the seed.
OK — HTH
Paul M.
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