Similar to the much more common Albizia julibrissin (Silktree Mimosa), but larger (60+ feet tall), with larger leaflets, with fewer pairs of branchlets on the rachis (~5 vs. ~10), and rough bark.

Durham, NC 9/11/08.

Durham, NC 9/11/08.

The powderpuff flower clusters are similar to those of A. julibrissin, but paler, usually more creamy than pink.

The genus Albizia is frequently misspelled Albizzia.

Albizia lebbeck is a similar species that is naturalized in subtropical and tropical areas of the US, but has even larger, fewer leaflets, yellowish flowers, broader pods, smoother bark, and is not cold-hardy.

Leaf comparison of A. kalkora (coarse yellow green leaflets on top) and A. julibrissin (the fine dark green leaflets). A. kalkora should have 2-4 pairs of pinnae and 5-14 leaflet pairs on each pinna. The leaflets should be pubescent. A. julibrissin should have 4-12(20) pairs of pinnae and 10-30 leaflet pairs on each pinna.

In 2006, Mel Turner discovered that apparent hybrids of Albizia julibrissin x kalkora are frequent along Towerview and Circuit Drives at Duke. Indeed, the majority of trees in the area seem to be intermediate between the two species. Many of the photos on this page are likely this hybrid backcrossed with A. kalkora.

The bark is rough, quite unlike the smooth bark of A. julibrissin.

Comparison of the bark of Albizia julibrissin (in front) and A. kalkora.

Bark of a small tree (same tree as top photo).

Durham, NC 9/11/08.

Durham, NC 6/17/2009.

Durham, NC 6/17/2009.

Durham, NC 6/17/2009.

Hybrids between the two species are very common. On the Duke University campus, most individuals appear to be hybrids, with intermediate numbers of leaflets on each leaf. Here are a few examples.

Durham, NC 6/11/2009.

Durham, NC 6/11/2009.

Durham, NC 6/11/2009.