Plant Bios

by Francesca Gentile

In Organ Pipe Cactus National Monument, many species of plant life exist. Within the monument’s borders there are 643 species of plant life and although the majority of the land does not have plants, the areas such as the oasis Quitobaquito and the sky island hold the vast species of life.[1] Of these species, varieties, or subspecies are among those plants that live in the desert landscape. Trees and shrubs, cacti, and wildflowers are some of the most common species that populate the land. The size of the specimens of plant life include composites plants (characterized by florets arranged in dense heads that resemble single flowers)[2] grasses, legumes, cacti and euphorbs (plants are annual or pereannial  herbs, woody shrubs or trees).[3] In Organ Pipe Cactus National Monument different areas of land include Quitobaquito, and the sky island, both supporting most of the diverse life in the region.

Sky Islands are defined as a place of subtropical oaks, soaring pine-clad cliffs, and undulating hills of grassland and forest.[4] The sky island is found in the area of the Ajo Mountains on the eastern side of the park and other mountain ranges. In higher elevations there are different species of flora than those in the lower desert areas. The mountainous area of Organ Pipe Cactus National Monument supports at least 114 species, including junipers, scrub oak, and the Sonoran Desert rosewood.[5]

The junipers found in the area have the scientific name Juniperus coahuilensis, and are more commonly known as the redberry juniper. The juniper takes over the oak trees in the area by dominating the sunlight causing the weaker oak trees to die; junipers can be a large or small shrub. The juniper has cones that contain one seed with branches that form close to the ground. Some animals eat the berries that come from the tree, for example coyotes, foxes and birds are among those that benefit this plant. They are not only found in the Sonoran Desert region, but also in western Texas, and southwestern New Mexico. Similarly they are also are found in the northern part of Mexico.[6]

The scrub oak is found in California, Nevada, Utah, Colorado, New Mexico, Arizona, and Texas. The scientific name is Quercus turbinalla. It is a vascular plant (any of various plants, such as the ferns and seed-bearing plants)[7] and produces flowers.[8] This plant is abundant in the higher elevation and can be an important source of food for deer and other animals. They form in clump-like bushes and look like evergreen shrubs that produce fruits which are slender in size.[9]

The Sonoran Desert rosewood is found in the southern and eastern areas of the desert. The scientific name of the Sonoran Desert rosewood is Vauquelinia californica and is native to Arizona. The rosewood is a plant that has leaves, fruit, and flowers. The leaves are dark green and leathery. The fruit is small and dry. And the flowers are dense, small, clustered, and have five petals per flower.[10] These plants arm themselves with little black thorns. The plant is classified as a tree or shrub and blooms in May and June.[11]

In the oasis of Quitobaquito there are 261 species in 191 genera and sixty families. Quitobaquito is probably the best known oasis in Organ Pipe Cactus National Monument and supports about forty five percent of the total vegetation in only about three and a half percent of the total area of the Monument. Quitobaquito is a major crossroad for human activity and is a major area for vegetation in this desert area.[12]

One of the common plants found in the oasis of Quitobaquito is the wolfberry.[13] Wolfberries are slight tubular flowers that are pale and tend to hang downward. The wolfberry’s fruit is small, bright red, and tastes like a tomato. The leaves are spatulate leaves (spatula-shaped leaf; having a broad rounded apex and narrow base)[14] are one to two centimeters long.  The shrub is medium to large with no thorns and rigid branches.[15]

Other notable plants found in the desert area of Organ Pipe Cactus National Monument are cacti, trees, shrubs, and wildflowers. The organ pipe and saguaro cacti are the more commonly found, however the senita, chain fruit cholla, teddy bear cholla, Engelmann’s prickly pear, hedgehog, pincushion, and Arizona barrell are also found in the Monument. Some of the common tree and shrubs include cresote, brittle bnush, jojoba, palo verde, mesquite, ironwood, ocotillo, and elephant tree. And the wildflowers that can be found in the hot arid areas of the area include Mexican poppies, lupine, owl clover, bladderpod mustard, tackstem, globemallow, brittlebush, creosote, saguaro, organ pipe, and pincushion. Of course some of the cacti, trees, and shrubs have blooms making the desert colorful during some times of the year.

Within Organ Pipe Cactus National Monument twenty eight different cacti species inhabit the area. The spines on the cacti are used for protection and shade, and the thick skin helps preserve water. The twenty eight different species range from the large saguaro that matures to around forty to sixty feet tall[16] to the tiny pincushion reaching about two inches in height.[17] The flowers that bloom from the cacti range in colors of yellow, red, white, and pink.[18]

Organ Pipe Cactus or Stenocerus thruberi have white blooms which bloom at night during spring and summer. The stems arise from the grounds and can reach about ten feet with a twelve-foot wide spread.[19] The organ pipe is only found in Arizona and is vascular plant. The fruits of the plant are red spiny and develop fully by summer. By this time the fruit loses its spines the fruit becomes edible to both animals and humans.[20] Organ pipe cacti are sensitive to frost but can withstand temperatures down to twenty degrees Fahrenheit.

The saguaro (Carnegiea gigantean) has a smooth and waxy flesh, but is covered completely with two-inch spines that are located in the ribs of the cactus. Some saguaros live to be 200 years old.[21] This cactus is thick, usually with eighteen to twenty four inches diameter, and the water held in the cactus is stored in the vertical ribs. In the summer months of May and June, blooms adorn the branches of the saguaro; white flowers with yellow centers bloom on the ends of the branch during the night. The saguaro is the Arizona state flower. Many animals, including insects, bats and pack rats eat from the saguaro.[22]

Mammillaria species comprise many varieties of cacti one known as the pincushion is a small variation within the Mammillaria species. Instead of a spiny protection the pincushion’s defense has adapted raised thorny nipples also known as tubercles.[23] Each of these are clustered for protection. If the thorns are straight than the cacti is a classified as pincushion, and a cacti with curved thorns are classified as fishhook cactus, but the fishhook is not found in Organ Pipe Cactus National Monument.[24] From California and Texas there are about two hundred species of the Mammillaria species.

Trees and shrubs are overwhelmed by the cacti in the monument; however trees and shrubs collectively are the most widespread of species. These species have adapted to the extreme temperature but they are all protected so they can remain well-preserved for the future.[25]

The creosote, Larrea tridentate is a blooming shrub. Blooming in spring, summer, and fall, the flower has five twisted petals that are round, lobed, hairy and white. The leaves are shiny, green, and waxy and are single split into two leaflets.[26]  The creosote shrub gives off an odorous smell especially after rain and produces mild allergens.[27]

The brittle bush is associated with the palo verde, and is characterized as having a woody base, and has many rounded branches. The scientific name of the Brittle bush is Encelia farinose.[28] The umbrella shapes of the leaves support the loose clustered flowers.[29] This plant is a short-lived species that is native to this area of dry arid land. The blooms are yellow and need full sunlight and heat to survive although they can withstand temperatures that reach twenty degrees.

The wildflowers in Organ Pipe Cactus National Monument make the area a vibrant scene, but because the blooms depend on winter rain the outcome is unpredictable.[30] Mexican Poppies and Lupines are some of the common types of flowers in the monument. The Mexican poppy or Eschscholtzia californica is a yellow to orange flower that blooms from January to May. The flower only blooms in full sunlight and has a stem that is fern like.[31] The lupine flower scientific name is Lupinus arizoniu. It has colors of pink, purple, and blues. The flower is native to Arizona and blooms in spring.[32] The flowers of the lupine are spiraled and sit along hairy stems with many per stem. The actually flower is small and is about half an inch.[33]

Although the rough, dry, arid land of the Organ Pipe Cactus National Monument is harsh, the vegetation is vast and diverse. Because many of the plants rely on rain during the winter, many of the plants have had the ability to adapt and survive. The adaptation of the vegetation has made the landscape of the monument unique, and many of the species found here are found nowhere else in the United States.[34] 


[1] Felger, Richard Stephen, Susan Rutman, Michael F Wilson and Kathryn Mauz. Botanical Diversity of Southwestern Arizona and Northwestern Sonora.

[2] The Free Dictionary by Farlex. http://www.thefreedictionary.com/composite+plant

[3] Felger, Richard Stephen, Susan Rutman, Michael F Wilson and Kathryn Mauz. Botanical Diversity of Southwestern Arizona and Northwestern Sonora

[4] Skroch, Matt. Sky Islands of North America: A Globally Unique and Threatened Inland Archipelago. Terrain.org. http://www.terrain.org/articles/21/skroch.htm

[5] Felger, Richard Stephen, Susan Rutman, Michael F Wilson and Kathryn Mauz. Botanical Diversity of Southwestern Arizona and Northwestern Sonora

[6] Index of Information of Species. Juniperus Coahuilensis. http://www.fs.fed.us/database/feis/plants/tree/juncoa/all.html

[7] The Free Dictionary by Farlex. http://www.thefreedictionary.com/vascular+plant

[9] Plants Profile Quercus turbinella Greene Sonoran Scrub Oak. USDA Natural Resource Conservation Service. http://plants.usda.gov/java/profile?symbol=qutu2

[11] Vauquelinia californica – Arizona Rosewood. Southern Arizona Wildflowers and Plants of the Sonoran Desert. http://www.fireflyforest.com/flowers/2515/vauquelinia-californica-arizona-rosewood/

[12] Felger, Richard Stephen, Susan Rutman, Michael F Wilson and Kathryn Mauz. Botanical Diversity of Southwestern Arizona and Northwestern Sonora.

[13] Corey. Quitobaquito at Organ Pipe Cactus National Monument…& A Trip to the Mexican Border. On The White Line: Merging the Joys of Life + Work + Travel. http://www.onthewhiteline.com/2012/02/quitobaquito-organ-pipe/

[14] The Free Dictionary by Farlex. http://www.thefreedictionary.com/spatulate+leaf

[17] Pincushion Cactus. Encyclopedia Brittanica Facts Matter. http://www.britannica.com/EBchecked/topic/460858/pincushion-cactus

[18] Organ Pipe Cactus. Cacti of the Monument. http://www.nps.gov/orpi/naturescience/cacti.htm.

[19] Master Gardeners of University of Arizona Pima County Cooperative Extension. Stenocereus thurberi Organ Pipe Cactus. http://ag.arizona.edu/pima/gardening/aridplants/Stenocereus_thurberi.html

[25] Organ Pipe Cactus. Trees and Shrubs. http://www.nps.gov/orpi/naturescience/treesandshrubs.htm

[26] Larrea tridentat – Creosote Bush. Sothern Arizona Wildflowers and the Plants of the Sonoran Desert. http://www.fireflyforest.com/flowers/1384/larrea-tridentata-creosote-bush/

[27] Larrea tridentat – Creosote Bush. Sothern Arizona Wildflowers and the Plants of the Sonoran Desert. http://www.fireflyforest.com/flowers/1384/larrea-tridentata-creosote-bush/

[28]Index of Species. Species Encelia Farinosa.  http://www.fs.fed.us/database/feis/plants/shrub/encfar/all.html

[29] Index of Species. Species Encelia Farinosa. http://www.fs.fed.us/database/feis/plants/shrub/encfar/all.html

[32] Lupinus arizonicus Arizona Lupine. Southern Arizona Wildflowers and the plants of the Sonoran Desert. http://www.fireflyforest.com/flowers/1442/lupinus-arizonicus-arizona-lupine/

[33] Lupinus arizonicus Arizona Lupine. Southern Arizona Wildflowers and the plants of the Sonoran Desert. http://www.fireflyforest.com/flowers/1442/lupinus-arizonicus-arizona-lupine/

[34] Felger, Richard Stephen, Susan Rutman, Michael F Wilson and Kathryn Mauz. Botanical Diversity of Southwestern Arizona and Northwestern Sonora.