Xanthocerus sorbifolium - Shinyleaf Yellowhorn
Family - Sapindaceae
Size - 15 to 20 feet in height, spread is approximately 2/3rds the height. Habit is upright and stiff. Appears to grow at a slow to moderate rate, 1 to 1 1/2' per year. Despises being container grown, at least in my experience.
Foliage - Alternate, pinnate, 6"-8" in length with an odd number of leaflets. Leaflets are approximately 2" to 21/2" in length. Fall color is a dingy yellow.
Flower/Fruit/Seed - Flowers are clustered in panicles on the terminal ends of branches and lateral branches. Individual flowers are white, roughly 1" across. The throat is initially yellow, turning to a carmine red. Flowering occurs in early to middle April and lasts for about 10 days. Fruit is a 3 valved capsule containing 3 dark brown pea sized seeds. Begins blooming at a very young age.
Pests and Diseases - Seems to get infected by a leaf blotch in late summer which can cause partial or total defoliation.
Landscape Use - With pruning it could be used as a accent in the residential landscape. Its habit doesn't give a whole lot to be worked with. Seems to be rather stiff and unkempt looking especially when young. Winter habit is coarse and unrefined. This tree is so virtually unknown I am doubtful that it will ever become available or used much. Rarely seen outside of gardens or collections, and is more of a novelty or collectors item. Could 'possibly' make a nice plant with some attention.
Performance - 5 Should do well in to the southern reaches of zone 7, cold hardiness should be fine in to the northern reaches of zone 5. Prefers full sun but will still do well in part shade for a portion of the day. Prefers loamy soils with adequate moisture, will not tolerate wet soils, it is tolerant of calcareous soils. Keep from windy sites. Can be injured by late freezes as it flowers very early with the foliage.