[Discoid Arnicas: The Genus Arnica in Mount Adams Country]

Nodding arnica spotted at left in open forest along the Sunrise Climber's Trail about one-half mile up from the trailhead, Yakama Nation lands at Bird Creek Meadows.....August 10, 2023. The photo at right shows nodding arnica on the slope below Crooked Creek Falls, Yakama Nation lands at Bird Creek Meadows.....August 18, 2023.

Parry's arnica beginning to bloom at left along the Island Springs Trail #66 just uphill from where the trail reaches the crest of the Ridge of Wonders, Mt. Adams............August 13, 2012. The photos at and at right show Parry's arnica beginning to bloom near the summit of Green Mountain, several miles northwest of Mount Adams, Gifford Pinchot National Forest......August 5, 2022.

Two photos showing the discoid inflorescence of nodding arnica as seen along forest road 82 above spur road 190 on the southeastern side of Mt. Adams.......July 1, 2005. The flower heads are typically lacking in ray flowers, which if present, are greatly reduced in size and number. Note the numeorus long, spreading, gland-tipped hairs on the involucre and on the upper stem.

The photo above shows a basal leaf of nodding arnica as seen along forest road 82 above spur road 190 on the southeastern side of Mt. Adams.........July 1, 2005. The leaves of this species are broadly lanceolate to lance-ovate in outline with entire margins or if present, regularly toothed. The similar rayless arnica (Arnica discoidea), has leaves that are ovate to somewhat heart-shaped with irregularly toothed margins.

Nodding arnica as photographed at left at the small frog pond along the Round the Mt. Trail at the east end of Bird Creek Meadows.......mid September 1998. Note that this species lacks or has reduced ray flowers. The photograph at center shows an aging lower leaf of nodding arnica as photographed at the small frog pond along the Round the Mt. Trail at the east end of Bird Creek Meadows.......mid September 1998. The photo at right shows the seed head of nodding arnica as photographed at the small frog pond along the Round the Mt. Trail at the east end of Bird Creek Meadows.......mid September 1998.