Description: Tree with narrow, conical crown of slender, upright branches and with resinous, balsam-scented buds.

Height: 15m

Diameter: 0.5m

Leaves: 5-13 cm long, 1-2.5 cm wide, lanceolate, long-pointed at tip, rounded at base; finely saw-toothed, hairless or nearly so, with short petioles. Shiny-geen above, paler below, turning dull yellow in autumn.

Bark: yellow-green and smooth on the slender, hairless twigs. Becoming grey-brown and furrowed with age.

Flowers: catkins 4-8 cm long; reddish; male and female on separate trees in early spring before the leaves.

Fruit: the female catkins lengthen and develop many broadly egg-shaped capsules about 6mm long, light brown and hairless. These mature in late spring, splitting into two parts to release many cottony seeds.

Habitat: Moist soils along streams in mountains; with willows and alders in coniferous forests.

Range: Mountains from S Alberta and extreme SW Saskatchewan south to Trans-Pecos Texas and California; also northern Mexico; at 900-2500m.

Discovered in 1805 by the Lewis and Clark expedition. They noted that horses would not browse on this species, unlike the willows and cottonwoods of the east. This is the common cottonwood of the northern Rockies. It has much narrower (willow-like) leaves than related cottonwoods and poplars, but forms a bigger tree than most willows in its range. Rare in cultivation in the UK, and apparently not yet seen to flower here. It seems to develop bushy headed, with short, much-forked, crooked branches and indeed this is the form that most of our own introductions took at first, although becoming somewhat more upright with age.

Information: Audubon (1980)

Source: Six cuttings taken (each from a separate tree) in October 1995 from trees growing at Rockcliff at the side of the Jordanelles reservoir in Utah (collectors' reference A&MW 95/55). These large trees line the banks of the river as it enters the lake, and are used as nesting sites by bald eagles in the spring - the photo above was taken at this site.

Planted: The base of the cuttings were wrapped in damp kitchen towel and the whole lot packed in plastic bags to be brought back to the UK padded inside a rucksack. They were planted in our mist-propagator within a few days, having had a clean basal cut made just before planting. Every one rooted and survived potting. The first of these was planted in late 1996, at B1F on the southern edge of our US strip (Rocky Mountain Riparian Forest zone).

Progress: The first one planted out was strimmed level with the ground in the spring after planting, but promptly sent up a new shoot and recovered well. This tree is now starting to become shaded by an adjacent willow, which needs pollarding this winter. On 2004.09.27, the B1F specimen was 1.6m. After this mishap, the others were kept potted until tall enough to avoid accidents. Several of these seem reluctant to grow very straight, but all are now ready to be planted. The biggest of these, a much bushier specimen, was planted at C11O near the southern boundary 1999.05.12 and this is growing well, despite having had a few twigs eaten off by cows (clearly less fussy than horses in the American West). in 2004, this was 2.4m, while another specimen, planted closer to the fence and more accessible to cows was stuck at 1m. If the remaining ones can be extracted from their pots (they have rooted through the bottom of the pots) they will be added to this boundary after two over-grown willows have been severely pollarded.

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