Flyin' Weeds: ..The case of a Trash Tree, Leucanea leucocephala.

[Silas_Sancona]

A few shots of what happens each year during monsoon season when the wind blows through the neighborhood White Lead Trees, Leucaena leucocephala.. A sparse and short, ( normally )  introduced tree that can be invasive. 

While the green pods are used as a vegetable in some parts of the world, the tree is grown mainly as fast growing, green manure / paper pulp, forage and fodder source. Unfortunately, foliage of this tree produces the toxic Amino Acid, Mimosine, which can cause livestock such as Cattle or Horses that consume it to loose their hair. In some cases, this can be overcome by inoculating these animals with one of a few micro organisms which help neutralize Mimosine in the guts of these animals. 

Seeds also contain toxic amounts of this amino acid making them unattractive to seed eaters. Tree itself is considered Alleopathic and can subdue growth of other plants near it.

In the landscape, most specimens you see here are short, scrappy, and sparse, esp. this time of year when they drop a good proportion of their foliage. At the same time, they are full of 8-12" long papery pods that are easily blown around ..full of seeds that can pop up just about anywhere and are tough to remove if allowed to grow longer than 1 year.

One of those trees no one really wants around, unless you consume the pods i guess.. Luckily, wind direction kept this swarm of pods out of the yard.. This time around..  PLENTY of pods still hanging on those trees, just waiting for the next good windstorm..








 

[tropicbreeze]

Leucaena is widely used here by cattle graziers, they swear by its benefits. They don't have to innoculate all their cattle against the toxicity, the bacteria spread fairly quickly through the herd. But cattle have to be already eating the Leucaena before the innoculation, otherwise the bacteria die of starvation. They have a "code of practice" which requires the graziers to maintain and control the plants to prevent their spread. We all know how well that works.

Leucaena has been bred and hybridized to produce all sorts of varieties. But they haven't developed seed that produce sterile plants. The original plants were brought in about 120 years ago and are well established in many areas. Like any legume they're hard to eradicate. They form very dense thickets which advantage some animals and disadvantage others. Their very highly efficient nitrogen fixing ability benefits some of the surrounding plants but the dense growth and shade wipes out others. Nature always reaches an overall balance. On the individual species level it's very much a mixed bag.

 

[Kailua_Krish]

These awful trees carpet the drier areas of the hawaiian islands and have made reforesting of native drylands species nearly impossible