Acacia cultriformis, commonly called Knifeleaf Acacia, is a shrub that I added to my landscape last year. I thought it was unusual looking, and since I was looking for a small multi-trunk tree for an area that gets too much morning sun, it was a nice change from the more commonly chosen Caesalpinia mexicana (Mexican Bird of Paradise.) This Acacia will eventually grow to about 15 feet high and wide. The tough leaves are triangular and are located on the branches. As with most Acacias, it will have little yellow puff-ball flower clusters in spring. Acacia flowers have a wonderful fragrance reminiscent of honey. I located it so that it will eventually shade my large dining room window as well as provide that fragrance when the windows are open in spring.
This plant is good in USDA Zones 9-12 and requires little water once established. It loves full sun, but will take light shade. Interestingly, I've never seen any of these during the many garden tours I've attended, nor have I noticed them used in public areas. I asked the nurseryman at the place I purchased it if this was an indication that there was some problem with it, even though it matches well to our climate and conditions. He said that this shrub is not yet well known here, but he predicts that as locals see these as they grow into small trees they will become more popular, especially with folks who have smaller yards needing small desert-adapted trees.
I'm hoping it doesn't have the negative that many other Acacias have--numerous volunteer plants from easily sprouted dropped seeds. Only time will tell!