[The Genus Polygonum East of the Cascades of Oregon and Washington]

Alpine Fleeceflower, Alpine Knotweed, Jimson Knotweed, Pokeweed Fleeceflower

Aconogonon phytolaccifolium var. phytolaccifolium

Synonym: Polygonum phytolaccifolium

Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)

Alpine fleeceflower as seen on open slopes atop the summit ridge of Anthony Lakes Ski Area, Wallowa-Whitman National Forest...........July 25, 2013.

Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)The photo at right shows a close-up of the terminal and subterminal, axillary panicles of alpine fleeceflower at Dixie Butte in the Malheur NF..........July 4, 2002.
Characteristics:

Alpine fleeceflower is also known as alpine knotweed or Jimson knotweed. It is an herbaceous perennial with several stems arising from a large branched crown and thick root from 80-120 cm high. The stout, erect stems are glabrous and either simple or branched above. The stems are also grooved. The numerous, crowded leaves are all found on the stems. They are shiny, lanceolate in outline with entire or wavy margins. They are alternate on the stems with short petioles or they may be almost sessile. The blades range from 6-12 cm long with the leaves only slightly reduced upwards on the stems.

The flowers are clustered into terminal panicles which may be leafy or not. They may also be found in subterminal panicles in the axils of the upper leaves. The flowers are white or greenish-white and range from 2.5-3 mm long. The 5 segments of the perianth are elliptic to obovate in shape and roughly the same size and shape, or occasionally with the inner two segments much reduced in size. The 8 stamens are shorter than the perianth segments. The 3 styles are only about 0.5 mm long. The fruit is a brown, shiny, sharp-angled achene from 5-6 mm long.


Habitat:

Alpine fleeceflower may be found on open slopes and ridges from subalpine to alpine habitats. It may be found in dry meadows, on talus, or amongst rock slides in these areas.


Range:

Alpine fleeceflower may be found from the Cascade Mts and Sierra Nevada Mts east in mountainous areas to Idaho, western Montana and western Nevada. It is found northward to Alaska.


Importance:

Alpine fleeceflower is an indicator of disturbed habitats. It moves into over-grazed alpine meadows and into areas impacted by landslides or avalanches. Elk browse the flowering tops but the plant is generally avoided by cattle and sheep. The Nez Perce used the seeds, after drying and grinding as a flour, while they roasted or boiled the roots for food.


Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)

Alpine fleeceflower as seen in open forest above Hoffer Lake, Wallowa-Whitman National Forest...........July 25, 2013.

Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)

The photo above shows a cluster of alpine fleeceflower at Dixie Butte in the Malheur NF.........July 4, 2002.

Inflorescence of Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)
The photo above is a close-up of the flower head of alpine fleeceflower as seen near the Dixie Butte Lookout, Malheur NF..........July 4, 2002.

Leaf of Pokeweed Fleeceflower, Alpine Knotweed, Jimson Knotweed: Aconogonon phytolaccifolium var. phytolaccifolium (formerly Polygonum phytolaccifolium)

The photo above shows the leaf of alpine fleeceflower as seen on the Frances Lake Trail in the Eagle Cap Wilderness.........July 25, 1997.

Paul Slichter