Scientific: Erythrostemon gilliesii (Synonym: Caesalpinia gilliesii)
Common: There are many common names for this plant. They are in no
particular order - desert bird-of-paradise, desert bird, bird-of-paradise shrub, or bird-of-paradise bush. Sometimes people get Erythrostemon gilliesii confused with Erythrostemon mexicanus and call it yellow or Mexican bird-of-paradise (even though the flowers have bright red stamens). This is problematic and demonstrates why the use of scientific names rather than common names to identify plants is important even if it seems like every few years they are arbitrarily changed by some new metric of phylogenic classification.
Family: Fabaceae (Leguminosae)
Origin: Native to Argentina and Uruguay, but has now naturalized in portions of the Chihuahuan and Sonoran Deserts in close proximity to
inhabited areas.
Taxonomic note: The Caesalpinia group [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 desert bird-of-paradise that was proposed by Gagnon, et al. (2016) in PhytoKeys 71:1-160.
Pronounciation: Er-i-thro-STEM-on gil-ee-ES-ee-i
Hardiness zones
Sunset 12-16, 18-23
USDA 9-11
Landscape Use: Seasonal accent, quick background shrub, though its canopy is too sparse and open to make a screen, nice tropical shrub for transition to desert areas in oasis landscape design themes.
Form & Character: Upright, irregularly rounded and spreading, quite sparse, open, airy, wispy, festive, dry, warm, vulnerable.
Growth Habit: Partially-evergreen, woody, broadleaf perennial shrub, moderate growth to 8- to 10-feet tall with equal spread. This taxon has very brittle wood.
Foliage/Texture: Leaves twice pinnately compound, leaflets to 1/4 inch and less, light green, graying with age, stems without spines but with well defined lenticels; fine texture.
Flowers & Fruits: Yellow flowers with red filaments on terminal spikes, fruits are unsightly green pods in terminal clusters turning to brown pods in summer that are heavy and weigh down branches.
Seasonal Color: Festive yellow/red flower color in spring and fall.
Temperature: Heat loving like Caesalpinia pulcherrima. In Phoenix, the 'desert bird' is partially to fully deciduous during the coldest winters.
Light: Full sun
Soil: Tolerant, but annual fertilization uring late winter will increase foliage canopy density which is otherwise typically sparse to open.
Watering: Definitely needs some summer water in Phoenix.
Pruning: Head back lightly after bloom, but only as needed to promote a more excellent shape, never shear. Unlike Caesalpinia pulcherrima, don't severely or extensively prune the 'desert bird' as it is quite slow to recover. Because the stem wood of this shrub is SO brittle, one can easily prune this shrub with bare hands!
Propagation: Easily propagated by seed
Disease and Pests: None these days, though white flies used to be a problem during late summer and early fall during the later years of the 20th century.
Additional comments: The desert bird of paradise is a good, medium-sized, but very open-canopied and sparsely-foliated accent plant that attracts hummingbirds. Its use in the landscape can evoke connotations of being on vacation at some semi-arid, subtropical, exotic beach along the Pacific coast of southwestern Mexico.
