Cassia × nealiae 'Lunalilo Yellow'
Common Name: pink shower 
Type: Tree
Family: Fabaceae
Zone: 10 to 12
Height: 30.00 to 50.00 feet
Spread: 20.00 to 40.00 feet
Bloom Time: April to September
Bloom Description: Golden yellow
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Shade Tree, Street Tree, Flowering Tree
Flower: Showy, Fragrant
Leaf: Evergreen
Attracts: Butterflies
Other: Winter Interest
Tolerate: Drought


Winter hardy to USDA Zone 9b where it is grown in average, medium moisture well drained soils in full sun. Established trees have some drought tolerance. Site in locations protected from drying winds. Intolerant of hard frost.

A sterile hybrid that should be propagated by grafting or air layering.

Noteworthy Characteristics

Cassia × nealiae, commonly called rainbow shower tree, is a hybrid cross between C. fistula (golden shower tree) and C. javanica (pink-and-white shower tree). It typically grows to 30-50' tall. It is noted for producing a show-stopping bloom of lightly-scented, 5-petaled flowers in 8-12" pendant racemes from April to September, with the biggest concentrations of bloom occurring in July-August. Flower colors include various shades of white, yellow, pink, orange and red, with a flower typically containing two or more combinations of these colors. Each even-pinnate compound leaf (to 12-16" long) has 5-12 pairs of elliptic leaflets (each leaflet to 4" long). Some leaf drop usually occurs in March/April as a prelude to flowering, with leaves returning as flowering begins. This tree is often considered to be semi-deciduous or semi-evergreen because of the brief loss of leaves prior to flowering. Rainbow shower tree was first observed in Hawaii as a natural hybrid. Upon discovery of this hybrid, forester David Haughs (1861-1932) began purposefully pollinating the flowers of C. javanica with pollen from C. fistula to create additional plants. Distribution of the hybrids to the public began in 1918, subsequently resulting in extensive planting of the trees throughout Hawaii. Today, rainbow shower tree is one of the most common street trees now growing along major roads in Honolulu. The common name of rainbow shower tree refers to the shower of rainbow-colored spent flower petals that, at times, rains downward to carpet the ground. Advantages of this hybrid over the individual parents include (1) it is sterile, which results in better and more abundant flowering than either parent (2) it has a fuller canopy of foliage over the winter months, (3) it blooms for a longer period of time, and (4) it produces few if any seed pods which create clean-up issues when they ripen and fall.

Genus name comes from the Greek name for a genus of leguminous plants which provide the senna leaves and pods important in pharmacy.

'Lunalilo Yellow' is a yellow flowered form whose original growing site was on Lunalilo Street in Honolulu. Golden yellow flowers are fragrant. Although it produces a few seed pods each year, the seeds are sterile.


No serious insect or disease problems. Plants have some tolerance for brief light frost with temperatures to 25°F. Mildew and leaf spot may appear. Sterile hybrid that is usually propagated by grafting or air layering.


Ornamental landscape tree. Shade tree.