|Fremont Cottonwood at Zion Lodge, Zion National Park, Utah|
|Natural range of Populus fremontii|
Populus fremontii, the Fremont's cottonwood or Alamo cottonwood, is a cottonwood (and thus a poplar) native to riparian zones of the Southwestern United States and northern through central Mexico.   It is one of three species in Populus sect. Aigeiros
The tree is native to southwestern North America: in the Southwestern U.S. from California: eastwards through Nevada, Utah and Arizona and New Mexico, to Texas and Colorado; and in Mexico in the states of Baja California, Baja California Sur, Sonora , Chihuahua, Coahuila, Nuevo Leon, Mexico State, and Puebla. 
Populus fremontii is a large tree growing from 12 m (39 ft) - 35 m (115 ft) in height with a wide crown, with a trunk up to 1.5 m (4.9 ft) in diameter. The bark is smooth when young, becoming deeply fissured with whitish cracked bark on old trees.
The 3 cm (1.2 in) - 7 cm (2.8 in) long leaves, are cordate (heart-shaped) with an elongate tip, with white veins and coarse crenate teeth along the sides, glabrous to hairy, and often stained with milky resin. Autumn colors occur from October–November, mainly a bright yellow, also orange, rarely red.
The Inflorescence consists of a long drooping catkin, which blooms from March to April. The fruit is a wind dispersed achene, that appears to look like patches of cotton hanging from limbs, thus the name cottonwood.
The largest known Populus fremontii tree in the United States grows in Skull Valley, Arizona. In 2012 it had a measured circumference of 557 inches (14.1 m) or 46.4 feet, height of 102 feet (31 m), and a spread of 149.5 feet (45.6 m).
Subspecies or varieties
Two subspecies are currently recognized. Some confusion due to hybridization with a Rio Grande subspecies of Populus deltoides subsp. wislizeni had originally placed this Eastern Cottonwood subspecies as a P. fremontii subspecies, but it was removed in 1977.
- Populus fremontii subsp. fremontii, with synonyms P. f. var. arizonica - Sarg. and P. f. var. macdougalii - (Rose) Jeps. from California and west of the Continental Divide
- Populus fremontii subsp. metesae - Eckenwal., of arid areas of Mexico, and widely planted elsewhere, generally east of the Continental Divide
Populus fremontii is cultivated as an ornamental tree and Riparian zone restoration tree. It is used in planting for: wildlife food and shelter habitats and ecological restoration; larger native plant and wildlife gardens and natural landscaping projects, windbreaks, erosion control, and shade for recreation facilities, parks, and livestock.
Fremont cottonwood was used in the past by settlers and ranchers for fuel and fence posts.
- Traditional medicine
Native Americans in the Western United States and Mexico used parts of the Fremont cottonwood variously for a medicine, in basket weaving, tool making, and for musical instruments. The inner bark of Fremont cottonwood contains vitamin C and was chewed as an antiscorbutic, or treatment for vitamin C deficiency. The barks and leaves could be used to make poultices to reduce inflammation or to treat wounds.
The Pima people of southern Arizona and northern Mexico lived along Sonoran Desert watercourses and used twigs from the tree in the fine and intricate baskets they wove. The Cahuilla people of southern California used the tree's wood for tool making, the Pueblo peoples for drums, and the Lower Colorado River Quechan people in ritual cremations.
- Populus fremontii information from NPGS/GRIN
- USDA Plants Profile for Populus fremontii (Fremont's cottonwood)
- "Jepson Manual treatment: Populus fremontii subsp. fremontii". University of California Press, ©Copyright 1993 by the Regents of the University of California.
- "USDA Plant Fact Sheet". United States Department of Agriculture. Retrieved February 5, 2002.
- "Range Plants of Utah". Utah State University. Retrieved 2002.
- "Populus fremontii ssp. fremontii". American Forests.
- Eckenwalder, J.E. (1977). "North American cottonwoods (Populus, Salicaceae) of sections Abaso and Aigeiros". Journal of the Arnold Arboretum 58 (3): 193–208.
- "Digital Desert: Mojave Desert". MojaveDesert.net. undated.
- Calflora Database: Populus fremontii (Fremont cottonwood)
- Calflora Database: Populus fremontii ssp. fremontii
- Populus fremontii — U.C. Photo gallery
- Populus fremontii ssp. fremontii — U.C. Photo gallery
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