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    Some floras treat Populus acuminata as a hybrid and thus the plant name would be written as Populus ×acuminata, the x showing that it is a cross, a hybrid. In other floras, such as Flora of the Four Corners Region, the name is written as Populus acuminata with this explanation: "usually treated as a hybrid between P. angustifolia and P. deltoides but often occurring in the absence of one or both reputed parents. Probably better treated as a hybrid derived species".

     James Eckenwalder, Populus expert and author of the Populus treatment in the Flora of North America explains the plant's name, habitat, and biology as follows:

Populus ×acuminata Rydberg is the intersectional hybrid of P. angustifolia [sect. Tacahamaca] with P. deltoides (sect. Aigeiros) that occurs on floodplains of major streams, primarily along the foot of the Rocky Mountain Front Ranges where these species grow together, but also extends onto the plains and Colorado Plateau (Alberta, Arizona, Colorado, Montana, Nebraska, New Mexico, North Dakota, South Dakota, Texas, Utah, and Wyoming) (J. E. Eckenwalder 1984). As with other cloning hybrids, it can often occur without one or both parents. It differs from P. angustifolia in larger, ovate leaves with coarser teeth, less color differentiation between abaxial and adaxial surfaces, and longer petioles that are slightly flattened side to side near the junction with the blade.

Because of its frequency and morphological consistency, P. ×acuminata was first described as a species and is often treated as such in local and regional floras. It was long suspected of being a hybrid, and its hybrid origin was amply confirmed by multiple lines of evidence in the 1970s and 1980s (D. J. Crawford 1974; A. G. Jones and D. S. Seigler 1975; S. B. Rood et al. 1985). The name has also been widely misapplied to intersectional hybrids involving other combinations of balsam poplar and cottonwood parents (Eckenwalder).

      "Populus" is Latin for "people" and is the classical Latin name for the tree.  "Acuminata" refers to the leaf shape and is from the Latin for "pointed".

Populus x acuminata
Twenty-five year old Populus ×acuminata trees above McElmo Creek with Mesa Verde in the background.
Populus x acuminata
Populus ×acuminata (Lanceleaf Cottonwood)
Salicaceae (Willow Family)

Semi-desert, foothills. Washes, wetlands, streamsides. Spring.
Hawkins Preserve, Cortez, May 13, 2015.

Populus ×acuminata is, as discussed above, a hybrid of Populus angustifolia and Populus deltoides, two very common trees of the Four Corners area. The hybrids shown on this page are only abut 25 years old as they are the root sprouts of larger trees that were destroyed in a fire.

These hybrids can spread from roots, as they have in the photographs, but they can also produce seeds after being fertilized by Populus angustifolia. The trees that result from this cross (a "back cross") get genetically and morphologically closer and closer to P. angustifolia.

The species name is also written as Populus acuminata.

Populus x acuminata
Populus ×acuminata (Lanceleaf Cottonwood)
Salicaceae (Willow Family)

Semi-desert, foothills. Washes, wetlands, streamsides. Spring.
Hawkins Preserve, Cortez, May 13, 2015.

Populus x acuminata

Populus ×acuminata (Lanceleaf Cottonwood)
Salicaceae (Willow Family)

Semi-desert, foothills. Washes, wetlands, streamsides. Spring.
Hawkins Preserve, Cortez, May 13, 2015.

Populus x acuminata gall

Populus ×acuminata (Lanceleaf Cottonwood)
Salicaceae (Willow Family)

Semi-desert, foothills. Washes, wetlands, streamsides. Spring.
Hawkins Preserve, Cortez, May 13, 2015.

The poplar bud gall produced by the mite, Aceria parapopuli, is common on the pictured P. xacuminata. Galls can be up to several inches long and an inch wide and can affect a tree's growth if they spread widely through the tree. According to the Field Guide to Plant Galls, little is known about the mite that causes these galls.

Range map © John Kartesz,
Floristic Synthesis of North America

State Color Key

Species present in state and native
Species present in state and exotic
Species not present in state

County Color Key

Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Native species, but adventive in state
Eradicated
Questionable presence

Populus x acuminata

Range map for Populus x acuminata