Scientific: Tara cacalaco (formerly Caesalpinia cacalaco with several synonyms: Coulteria mexicana, Russellodendron cacalaco, and Poinciana horrida)
Common: cascalote
Family: Fabaceae (Leguminosae)
Origin: Latin America north into central Mexico
Taxonomic note: The Caesalpinia tribe [subfamily Caesalpinioideae (family Fabaceae or Leguminosae)] has been in a state of considerable taxonomic flux over the last 30 years. For practicing horticulturists, this has created much industry confusion - a real hot mess! Presently, I am using the botanical name for cascalote that was proposed by Gagnon, et al. (2016) in PhytoKeys 71:1-160.
Pronounciation: TAR-a ka-ka-LA-ko
Hardiness zones
Sunset 12-16, 18-23 (coastal zone 17 with a warm exposure)
USDA 9-11
Landscape Use: Winter seasonal accent, focal point, quick background screen, habitat gardens, small multi-trunk tree.
Form & Character: Used mainly as a large shrub or multi-trunk small tree, arborescent with age, open, festive, warm and attracting.
Growth Habit: Semi-evergreen (briefly deciduous in early spring), woody, perennial, vigorous and upright to 15 to 25 feet or more with and equal to greater spread. Basal suckering is common making this a somewhat difficult taxon to train and maintain as a single trunk standard.
Foliage/Texture: Leaves twice-pinnately compound, leaflets to 3/4 inch or less, medium to dark green, new growth and stems tinged purple, stems also have large, persistent thorns; medium coarse texture.
Flowers & Fruits: Large, mostly yellow candelabra flowers on terminal spikes; fruits are constricted pods, mostly indehiscent, yellowish green when young turning to an interesting reddish-brown at maturity.
Seasonal color: Festive, yellow color in late fall and early winter.
Temperature: Cascalote is heat tolerant (thrives in Phoenix). It is also the most cold tolerant (18oF) of all the plant taxa in the Caesalpinia tribe that are found in Phoenix landscapes.
Light: Full sun
Soil: Tolerant
Watering: Cascalote needs some infrequent, deep supplemental water applied, especially during summer.
Pruning: Cascalote's arborescent habit makes raising the crown and canopy into a small, multi-branched tree a good practice. Prune during spring after bloom.
Propagation: Seed (needs acid scarification), softwood cuttings, grafting, stem air layering.
Disease and Pests: White flies are only a minor problem.
Additional comments: Cascalote is a colorful flowering accent or background shrub (or small multi-trunk tree) for southwestern landscapes. Its blooms can attract hummingbirds, though hummingbirds are not as prevelant in Phoenix during its bloom time (late fall to early winter). In the spring after flowering it tends to go briefly deciduous (which can surprise many to think, "oh man, it just died").
Cascalote does have stout, protruding stem thorns that make it a landscape plant that should not be used close to pedestrian access ways. However, there's one notable exception to this warning. It's the cultivar 'Smoothie' (a grafted selection), which lacks stem thorns. Because of this, 'Smoothie' is currently a wonderful, very popular 'small tree' for water-conserving landscape gardens in the lower deserts of the Southwest.
Medicinal note: Cascalote seed pods are a rich source of tannins, which have antioxidant activity.
