[The Genus Agoseris East of the Cascade Mts. of Oregon and Washington]

Spear-leaf Agoseris, Spear-leaved Agoseris

Agoseris retrorsa

Synonym: Macrorhynchus retrorsus

Involucral bracts of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)

The photo above shows spear-leaf agoseris as seen at a DNR rock quarry at about 4100' abreast the ridgetop between the Dairy Creek and Cougar Creek drainages on the southeast corner of Mt. Adams.........May 29, 2005.
Achenes and beak of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)The photo at right shows a key identifying characteristic of spear-leaf agoseris. The upper end of the achene or seed is squared off and the narrow beak which is plumed (or parachute-like) at its end. Photographed at Catherine Creek, central Columbia River Gorge.........June 3, 2006.
Characteristics:

Spear-leaf agoseris is a perennial wildflower with one to several erect, leafless scapes arising 15-60 cm high from a cluster of basal leaves atop a taproot. Plants typically begin with a covering of soft, shaggy, tangled hairs but eventually become glabrous with age, especially above. The leaves measure 8-20 cm long and are narrowly oblong, lanceolate or elliptical in outline and gradually tapering to a narrow tip at both ends. The margins are deeply lobed with the lobes generally long and linear with the lower ones spreading and the upper ones directed backwards.

A single flower head consisting entirely of ray flowers may be found atop each scape. The heads tend to be narrower than those found in the similar large-flowered agoseris. The involucre ranges from 2.5-5 cm long in fruit. The outer involucral bracts are shorter and lance-oblong in outline while the inner bracts are longer and broad below tapering gradually to the long linear upper portion. The rays are typically yellow, although they often dry to a pinkish color. The achenes are cylindrical, measure 5-6 mm long, and are truncate at the apex, with the beak about 3-4 times longer than the body of the achene.


Habitat:

Spear-leaf agoseris may typically be found in dry, open woods.


Range:

Spear-leaf agoseris may be found along the eastern edge of the Cascade Mts. from Chelan County in Washington south to California and Nevada and east through Oregon and Washington to southwestern Idaho.


Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus) - Flower head of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)

Close-up views of the whole plant as well as a flower head of spear-leaf agoseris as seen in oak woods in the Klickitat State Wildlife Area of south-central Washington.........May 27, 2009.

Leaf of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)

The photo above shows a basal leaf of this species. Note the numerous long hairs towards the lower half of the leaf as well as the deeply divided leaf with the lobes pointing outwards or slightly downwards towards the base of the leaf.

Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus) - Seed head of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)

Spearleaf agoseris with well-formed seed heads as seen at Camas Lands NAP to the southeast of Leavenworth, Washington..........June 5, 2015.

Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus) - Seed head of Spear-leaf Agoseris, Spear-leaved Agoseris: Agoseris retrorsa (Synonym: Macrorhynchus retrorsus)

The photo at left shows spearleaf agoseris from DNR lands along the Yakama Nation boundary at the southeast side of Mt. Adams........June 2005. The photo at right shows a seed head of spearleaf agoseris as seen along the Steins Pillar Trail, Ochoco National Forest........June 26, 2017.

Paul Slichter