Accession Count: 3
Common Name:
little leaf palo verde, foothill palo verde
Family Name:
Fabaceae
Botanical Name:
Cercidium microphyllum
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
The foothill palo verde is a small drought-deciduous, woody perennial tree with a multi-trunked form, generally growing from 5-7.5 m (~16-25 feet) (1, 2). It is slightly smaller in size than its close relative Parkisonia florida (blue palo verde). The bark on the trunk is smooth, yellow-green and has the ability to photosynthesize trunk and the stems are many-branched and spiny, forming an open spreading canopy (2). Leaves are deciduous during extreme heat and drought periods, alternately arranged, pinnately compound, green or yellow-green, with each pinnae having 4-7 leaflets (1, 2). Flowers appear in April or May in Southern Arizona, are mostly medium yellow, about 2.5 cm (1 inch) across with a white-cream banner petal (2). The flowers are distinct from the Parkinsonia aculeata (Jerusalem thorn) which have a red-brown splash of color on the banner petal and distinct from Parkinsonia florida (blue paloverde) which has solid and yellow keel and brighter yellow overall corolla (2). Fruit is a short, soft legume pod about 5-8 cm (2-3 inches) long with constrictions between the seeds.
Compound:
Cer mic
Geographic Origin:
Desert Southwest
Ecozone Origin:
Nearctic
Biome Origin:
Natural History:
The foothill palo verde is native to Southern Arizona, more specifically, the Tucson Basin where it grows in dry rocky hillsides and mesas at about 1200 m (4000 feet) elevation (1, 2). In Arizona it is mostly found primarily in the central and western half of the state and in California, it is occasionally found growing in San Bernadino County (2). In the Sonoran Desert, it is the most common of the tree species and, as such, it is considered an indicator species and a co-dominant plant creosote-bush (Larrea sp.), triangle leaf bursage (Ambrosia sp.), brittlebush (Encelia sp.), ocotillo (Fouquieria sp.) and wolfberry (Lycium sp) (2). Collectively, these plants are referred to as the paloverde, bursage desert scrub community (2). It is classified as "Salvage Assessed, Harvest Restricted" meaning a permit from the Department of Agriculture is necessary to transport this species off private property (2).
Cultivation Notes:
Since this plant grows mostly in dry rocky hillsides and mesas and, is less common in washes than its relative blue paloverde (Parkinsonia florida), which requires more regular water, it is clearly very drought tolerant. To satisfy its minimal water requirements, water deeply once per month in the summer and plant in soil with good drainage (1). While foothills palo verde are very hardy, it may suffer damage at temperatures below -9 C (~15F) (1, 2). It is a great tree for sunny areas but, is somewhat susceptible to both the parasitic mistletoe and to palo verde beetles (1). Foothills paloverde trees are slow growing and live more than 70 years of age (2).
Ethnobotany:
The foothill palo verde has wildlife value in that is produces seeds, nectar, and shaded cover 1). This tree is especially important to butterflies, moths, flies, honeybees, native bees, other insects, hummingbirds and small mammals including rodents and granivorous birds in search of nectar, food, shelter or protection (2). The seeds of this species were a valued food source for many of the southwestern tribes (1). Some would grind the seeds into a fine flour, which would then be added to water to make a soup or drink (1). They were eaten both raw and roasted (1). Specifically, Parkinsonia microphylla was used for food by people indigenous to the southwestern United States – the Cocopa used the tree as a source of food (3). Porridge was made by roasting the seeds, grinding them into a flower and make into mush (3). The Mohave ate the roasted seeds as a famine food (3) while the Papago ate the sun-dried beans and the Pima ate the beans fresh (3).
Height:
20 - 50 feet
Width:
16 - 20 feet
Growth Rate:
Slow Growing
Grow Season:
Summer
Flower Season:
Spring
Color:
Yellow
Function:
Shade
Spread:
Non-spreading
Allergen:
Allergenic
Invasive:
Benign
Toxicity:
Benign
Hardy:
Hardy
Water Use:
Low water Use
Citations:
1. Walters, James E, and Balbir Backhaus. Shade and Color with Water-Conserving Plants. Timber Press, 1992.
2. Southwest Desert Flora Retrieved June 15, 2024. https://southwestdesertflora.com/WebsiteFolders/All_Species/Fabaceae/Parkinsonia%20microphylla,%20Yellow%20Paloverde.html
3. Native American Ethnobotany University of Michigan. Retrieved June 15, 2024. http://naeb.brit.org/uses/search/?string=Parkinsonia+microphylla
