The scarlet wisteria tree is native to southern Brazil, northeastern Argentina, and Uruguay. The botanical name presents some difficulty. The plant was originally named Daubentonia Tripetii Poiret. It was then classified as Sesbania tripetii (Poir.) Hort ex F.T. Hubbard, a name published in a nursery catalog and used horticulturally, but not valid botanically. It is now thought the plant is Sesbania punicea (Cavanilles) Bentham.

The scarlet wisteria tree grows to about four meters in height. The compound leaves are evenly pinnate (no end leaflet). The flowers are a brilliant orangey-scarlet and borne on drooping racemes. The seedpods have four 'wings'. When mature, the seeds loosen and rattle within the pod. (This trait is totally unnerving to field personnel who are expecting to come upon rattlesnakes.)

Sesbania punicea is a nuisance exotic (non-native) in natural areas. It and other species of Sesbania are difficult to control within wetland mitigation areas. As the soil in wetlands becomes inundated, the lower portion of the stem splits and white spongy aerenchyma tissue protrudes through the splits. The plant grows additional spongy adventitious roots which serve to prop the plant in mucky soils.

The photographed plant threw me when I saw it in Mike's landscaping. It was very dramatic and bore little resemblance to the nuisance Sesbania--the flowers were much larger and deeper colored. The racemes were longer with more flowers. The landscape tree was woodier and not as 'rangy' as the invaders I have seen in mitigation areas. Perhaps, care in a landscape accounts for the difference in appearance or those in the horticultural trade are 'selected' for better performance.

Seeds I received from Mike had one hundred percent germination within five days, so it is highly probable this plant will get out of hand quickly in a garden and escape into natural areas.

The Nature Conservancy has additional information about Sesbania punicea. To learn more about the plant, click on the link:

http://tncweeds.ucdavis.edu/alert/alrtsesb.html