Index of Species Information
SPECIES: Parkinsonia florida
Pavek, Diane S. 1994. Parkinsonia florida. In: Fire Effects Information
System, [Online]. U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
Available: http://www.fs.fed.us/database/feis/ .
Cercidium floridum Benth ex Gray. (Fabaceae) [5,27,55,82]
Cercidium torreyanum (S. Wats.) Sarg. 
SCS PLANT CODE :
COMMON NAMES :
The currently accepted scientific name of blue paloverde is Parkinsonia
florida (Benth.) S. Wats. [62,82,83]. Besides the typical
subspecies that is recognized throughout most of the species range,
peninsular blue pale verde (described as C. f. ssp. peninsulare (Rose) Carter)
occurs in Baja California . Occasionally, blue paloverde hybridizes with
yellow paloverde (P. microphyllum) .
LIFE FORM :
FEDERAL LEGAL STATUS :
No special status
OTHER STATUS :
DISTRIBUTION AND OCCURRENCE
SPECIES: Parkinsonia florida
GENERAL DISTRIBUTION :
Blue paloverde is distributed through the Sonoran Desert. Its range
extends from central and southwestern Arizona into southeastern
California [15,25,35,39,62,68]. Blue paloverde continues southward
through western Sonora, Mexico [5,21,47]. Disjunct populations of blue
paloverde are located in northern Sinaloa and Baja California Sur
FRES30 Desert shrub
FRES40 Desert grasslands
AZ CA MEXICO
BLM PHYSIOGRAPHIC REGIONS :
7 Lower Basin and Range
KUCHLER PLANT ASSOCIATIONS :
K027 Mesquite bosque
K042 Creosotebush - bursage
K043 Paloverde - cactus shrub
SAF COVER TYPES :
SRM (RANGELAND) COVER TYPES :
HABITAT TYPES AND PLANT COMMUNITIES :
Blue paloverde is a characteristic member of the Sonoran Desert
floristic region [38,79]. It is a member of desert scrub communities.
Blue paloverde is a major component in creosotebush (Larrea tridentata)
and white bursage (Ambrosia dumosa) climax communities on lower bajadas
Blue paloverde is a facultative desert riparian species that may be
restricted to washes or arroyos in parts of its range but also occurs in
upland communities. It primarily occurs in communities irregularly
scattered along arroyos . These communities with intermittent water
are variously classified as desert riparian associations ,
pseudo-riparian communities , desert wash woodlands [7,13,53,71],
Colorado River riparian forests , and desert microphyll associations
. Codominants in all of these classifications are honey mesquite
(Prosopis glandulosa var. glandulosa), smoketree (Psorothamnus
spinosus), ironwood (Olneya tesota), desert willow (Chilopsis linearis),
and catclaw acacia (Acacia greggii) [52,58,71].
Blue paloverde is a dominant member of the mixed scrub series with
ironwood and jojoba (Simmondsia chinensis) . Within the broadleaf
woodland subformation, the paloverde series is dominated by either blue
paloverde or yellow paloverde; the understory is sparse in this series
Blue paloverde is listed as a dominant or indicator species in the
(1) A vegetation classification system applied to southern California 
(2) The vascular plant communities of California 
(3) Vegetation of the Santa Catalina Mountains, Arizona: a gradient
analysis of the south slope .
Species associated with blue paloverde but not previously mentioned in
DISTRIBUTION AND OCCURRENCE include desert hackberry (Celtis pallida),
desert lavender (Hyptis emoryi), big saltbrush (Atriplex lentiformis),
Torrey seepweed (Suaeda torreyana), spidergrass (Aristida ternipes), and
Rothrock grama (Bouteloua rothrockii) [23,47,49,68].
SPECIES: Parkinsonia florida
WOOD PRODUCTS VALUE :
The wood of blue paloverde is light to heavy, soft, and close-grained
[30,70]. Blue paloverde is used for fuel .
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Blue paloverde fruits, twigs, and leaves are used as livestock forage
throughout the year . Mule deer, bighorn sheep, and burros browse
its twigs and leaves [15,80]. Small mammals consume blue paloverde
seeds during summer and fall .
In southern Arizona, blue paloverde taller than 6.7 feet (2 m) is used
for nesting . With a large canopy, blue paloverde offers many sites
for bird perching, nesting, and foraging. The blue paloverde-ironwood
vegetation type supports a high density and diversity of breeding birds
[7,16,20]. In south central Arizona, 19 species of breeding birds were
present in mesquite (Prosopis spp.) bosques where blue paloverde
Blue paloverde leaves and stems contain cyanogenic glycosides,
alkaloids, and cinnamic phenolic acid which may deter herbivory .
NUTRITIONAL VALUE :
Blue paloverde aboveground biomass is about 22 percent nitrogen, 50 to
80 percent dry matter, and 17 percent crude protein [4,63,64,80].
Equations are available to predict amounts of dry matter, nitrogen, and
carbon based on blue paloverde height and crown measurements .
COVER VALUE :
VALUE FOR REHABILITATION OF DISTURBED SITES :
Blue paloverde has successfully established by artificial seeding
following highway construction .
Blue paloverde naturally established following removal of invasive
populations of saltcedar (Tamarix ramosissima) . Soil preparation,
planting, and irrigation methods for blue paloverde are discussed in the
OTHER USES AND VALUES :
Blue paloverde fruits have been used by Native Americans for food .
The Pima and Papago in Arizona cooked young blue paloverde fruits and
seeds and ground the seeds for porridge .
The Pima carved blue paloverde into large serving spoons .
OTHER MANAGEMENT CONSIDERATIONS :
Blue paloverde and other species were tested for biomass production for
use in fuelwood and erosion control programs. Blue paloverde and
ironwood ranked lowest of the tested species for biomass production .
Young blue paloverde can tolerate moderate grazing. In greenhouse
tests, blue paloverde sprouted following top removal. At a transplant
site near Travertine Point, California, severely gnawed blue paloverde
transplants survived only when irrigated .
Seed predation by invertebrates such as bruchid beetles can lead to
logarithmic increases in seed mortality of blue paloverde .
Blue paloverde has decreased in some areas of Arizona partly due to the
erosion of broad flat washes into narrow, steep-sided channels . In
the microphyll woodlands of the desert washes, disturbance by offroad
vehicles decreases density and biomass of perennial plants such as blue
Natural recovery following disturbance is slow in wash woodlands in
which blue paloverde occurs. Optimal conditions for reestablishment
occur infrequently. It may take up to 60 years for these woodlands to
reach predisturbance levels of biomass, and 180 years to reach
predisturbance levels of species diversity .
In southeastern California, blue paloverde is a nurse plant for saguaro
(Carnegiea gigantea) . Saguaro eventually outlive or contribute to
the death of paloverde species .
Blue paloverde does not have mycorrhizal nodules . The presence of
other mycorrhizal associations was not discussed.
BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Parkinsonia florida
GENERAL BOTANICAL CHARACTERISTICS :
Blue paloverde is a native, spiny, small tree or subtree [30,35,39,78].
It has multiple stems . Blue paloverde grows to 32.8 feet (10 m)
tall with a trunk diameter of 1.5 feet (0.5 m) and a crown spread of
163.4 square feet (15.2 sq m) [4,5,30,39]. Blue paloverde has
thin-barked, photosynthetic stems [3,66]. Age influences photosynthetic
rate of stems; younger stems have higher photosynthetic rates . Its
pinnately compound leaves are about 1 inch (2.5 cm) long and
drought-deciduous [3,30,54,66,78]. Inflorescences of blue paloverde are
1.5 to 4.7 inches (4-12 cm) long with one or more flowers [55,62,70].
The fruits are flat legumes, 1.5 to 4 inches (4-10 cm) long [39,62,70].
Each legume holds one to eight flat seeds [36,39,70].
RAUNKIAER LIFE FORM :
REGENERATION PROCESSES :
Blue paloverde reproduces sexually and probably asexually. In a
greenhouse study, young blue paloverde sprouted after plants were
clipped to less than one-half of their total height . A close
relative, yellow paloverde, sprouts following top-kill .
Photoperiod controls blue paloverde flower and fruit initiation and stem
growth; however, moisture and temperature determine actual organ
Abiotic and biotic agents aid in seed dispersal. The flat seeds of blue
paloverde prevent air loft and allow downward dispersal into washes.
Fruits and seeds do not float. Occasionally, blue paloverde fruits
disperse unopened. Some seed dispersal occurs via animals. Blue
paloverde has been found occasionally in ant formicaries below the soil
surface. Seeds will germinate in these caches. Birds probably move
seed upstream .
Large seedbanks of blue paloverde may be present. Scarification from
flash floods or other abrasive processes facilitates germination
[36,43,71,73]. Blue paloverde germinates well on sandy deposits .
Shade and litter beneath mature blue paloverde alters seed microsites
and makes germination more likely .
Blue paloverde establishment is limited by climate extremes, low
moisture availability, poor soil characteristics, and herbivory. Rapid,
deep root development is important for blue paloverde establishment. In
greenhouse trials, blue paloverde roots grew an average of 0.3 inch per
day (0.9 cm/day) . Mature blue paloverde has deep root systems that
reach ground water and make blue paloverde less vulnerable to drought
. A herbivory experiment was conducted on blue paloverde at
Travertine Point, California. Seven months after blue paloverde
germinated, rabbits and other rodents grazed 86 percent of the
seedlings. Ninety percent of these grazed blue paloverde seedlings
appeared unlikely to survive .
SITE CHARACTERISTICS :
Blue paloverde occurs in arid and semiarid climates characterized by
high summer temperatures and highly variable rainfall. Precipitation
predominantly falls bimodally, in winter and in summer [40,52,53,66].
Blue paloverde is found at elevations from sea level to 4,000 feet
(0-1,220 m) [4,15,26,34,74]. It occurs on almost level (less than 5%)
to steep slopes .
Blue paloverde predominantly grows in washes, but is also found in
upland habitats. Blue paloverde occurs in moderate to large watersheds
from 1 to 50 square miles (2.6-130 sq km) . It grows on terraces,
high flood plains, arroyos or dry washes, and intermittent streambeds
more than 4 to 5 feet (1.2-1.5 m) wide with deep soil [8,54,79,81]. In
the northern Sonoran Desert at moderately high elevations, blue
paloverde grows in upland positions . Blue paloverde occupies
hills, mountain slopes, and middle to lower bajadas [4,54,65].
Blue paloverde grows in soils with low levels of nutrients, especially
nitrogen and phosphorus . Soil textures it occurs on may be sandy to
gravelly, coarse loamy to fine sand overlain with fine gravel [4,54,65].
SUCCESSIONAL STATUS :
Blue paloverde occurs from pioneer to climax communities, depending on
site characteristics. In fact, classical succession may not occur in
the desert ecosystems where blue paloverde occurs. In the xeroriparian
systems to which blue paloverde belongs, community development is
influenced by catastrophic floods and long recovery periods . After
disturbance of the desert scrub communities, former dominants such as
blue paloverde are the first to appear and replace themselves .
SEASONAL DEVELOPMENT :
Flower and leaf production of blue paloverde vary according to the
amounts of precipitation received . Blue paloverde remains leafless
throughout most of the year . Leaves are produced between mid-July
and late November, depending on the summer rains . Leaves drop
during drought and are not replaced until the following spring .
Blue paloverde typically flowers sporadically after rains from late
March to May, but flowering may extend into July [5,15,30,66,70].
Populations of blue paloverde also may bloom August to October .
Fruits mature about 1 month after flowering, typically from May to July
SPECIES: Parkinsonia florida
FIRE ECOLOGY OR ADAPTATIONS :
Blue paloverde is susceptible to fire; its photosynthetic stems are
probably easily killed by fire. It may sprout from the root crown if
its postfire response is similar to its response to clipping.
The historical fire regime of the Sonoran Desert is mostly unknown .
Thomas  mentioned that fire free periods in the Sonoran Desert are
greater than 250 years. However, Loftin  stated that fires were
relatively common in the Sonoran Desert under appropriate conditions,
especially during summer. Fires that do occur are usually low-severity
due to small fuel loads .
Grazing and vegetation change have probably altered the fire regime from
historic patterns. On the Santa Rita Experimental Range in southern
Arizona, frequent fires were common until 1916 because dense stands of
grass were present. Fires were frequent at the turn of the century in
desert grasslands that border the desert scrub communities where blue
paloverde occurs. By the 1960's, fire frequencies had declined due to
grazing and fire suppression . In south-central Arizona, understory
vegetation beneath paloverde species, ironwood, mesquite, and saguaro
associations changed from grasses to low shrubs due to grazing
pressures. This has altered the fire regime, resulting in less frequent
fires . However, where introduced annual grasses now predominate,
fire frequency may have increased.
The Sonoran savanna grasslands are subtropical, fire-climax communities.
Blue paloverde occurs infrequently in these communities at their
northern limits .
FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find Fire Regimes".
POSTFIRE REGENERATION STRATEGY :
Tree with adventitious-bud root crown/soboliferous species root sucker
Secondary colonizer - off-site seed
SPECIES: Parkinsonia florida
IMMEDIATE FIRE EFFECT ON PLANT :
Blue paloverde with its thin photosynthetic bark is probably top-killed
by fire. Surviving rootstocks may sprout if the response of blue
paloverde is similar to yellow paloverde . If plants are heat
damaged, they may die several months after burning . Seeds are
probably killed by fire unless protected by insulating layers of soil.
DISCUSSION AND QUALIFICATION OF FIRE EFFECT :
PLANT RESPONSE TO FIRE :
In desert plant communities where blue paloverde occurs, 20 years may be
necessary for plant densities to recover to prefire levels [14,32,51].
Four years after a February 1964 fire in a southeastern California
desert scrub community, soils beneath burned and unburned woody plants
were surveyed. Soil beneath burned blue paloverde had a strongly
hydrophobic layer overlain by a slightly hydrophobic layer. Burned soil
had a slightly higher degree of water repellency than unburned soil.
This water-repellent burned soil causes a reduction of available water
moisture and inhibits germination of species such as annuals beneath
blue paloverde . This may protect blue paloverde from some fires.
Native annual plants probably did not create the same large fuel load
that introduced annual species currently provide .
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE :
FIRE MANAGEMENT CONSIDERATIONS :
It is difficult to control shrubs and trees with fire on arid habitats
due to lack of fuel. Two consecutive wet winters are probably necessary
to develop adequate fuel to sustain a fire in the desert scrub .
Prescribed fires once every 10 years would keep blue paloverde in check .
Depending upon the season of burning, soil nutrients may be quickly
translocated following fire on the desert soils where blue paloverde
occurs. Available nitrogen in the soil drops below prefire levels for
several years due to removal of nitrogen-containing ash by run-off.
Dry matter levels are useful for predicting flammability of fuels. Near
Tucson, Arizona, aboveground biomass of blue paloverde was 80.3 percent
dry matter .
SPECIES: Parkinsonia florida
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