"Senecio" is from the Latin, "senes", "old man", and refers to the pappus hairs, the tiny bristle, hair, or awn growth at the apex of the seeds in Asteraceae.

  See Senecio atratus for a discussion of the differences between Senecio, Ligularia, and Packera.

Montane, alpine. Woodlands, openings. Summer
Near Colorado Trail at the end of Hillside Drive, August 4, 2014.
Wildcat Canyon Trail, September 2, 2014.

Both Senecio triangularis (top photograph) and Senecio serra like moist openings in spruce forests. Both grow 3-5 feet tall with a topping of numerous flower heads.

Montane. Moist woodlands, openings, streamsides. Summer.
Roaring Fork Road, July 26, 2004.

Tall and in an open airy pattern, this Senecio likes subalpine woods and openings.  Notice the long, narrow, tapering, finely serrated (thus, "serra") leaves. Large patches of plants are common.  See Senecio triangularis immediately below for a comparison with S. serra; the two plants are very similar.

David Douglas (of Douglas Fir fame) first collected this plant "common on the banks of the Wallawallah, Flathead, and Spokan Rivers" (as quoted in  Intermountain Flora). The plant was named by William Hooker in his Flora Boreali-Americana in 1834. (Click the title to read.)

Montane. Moist woodlands, openings, streamsides. Summer.
Roaring Fork Road, July 26, 2004 and Lizard Head Trail, August 4, 2010.

Montane. Moist woodlands, openings, streamsides. Summer.
Roaring Fork Road, July 26, 2004.

Montane, alpine. Moist woodlands, openings, streamsides. Summer.
Above: Upper Priest Gulch Trail, August 22, 2019.
Left: Kilpacker Trail, July 22, 2004.

Senecio triangularis and Senecio serra can be difficult to tell apart, for they both grow in moist or wet woods in large patches, are up to four feet tall, have narrow and serrated leaves, and are topped with many small, yellow sunflowers.  S. triangularis is, however, far more common than S. serra, enjoys much wetter areas, and is usually taller than S. Serra.  The strongest visually distinguishing characteristic is that the base of each Senecio triangularis leaf is broad and relatively perpendicular to the leaf axis, creating a triangular leaf shape.  The leaves of S. serra taper symmetrically from a narrow leaf base to a wider center and then back again to a narrow leaf tip.  Leaves of S. triangularis are shallowly saw-toothed; leaves of S. serra are finely serrated.  
S. triangularis often has more leaves, grows in more dense patches, and has slightly larger flowers with a more prominent central dome of disk flowers.

Thomas Drummond collected this plant, probably on his second trip to the United States in the early 1830s.  The plant was named by William Hooker, Drummond's mentor, in his Flora Boreali-Americana in 1834, (Click the title to read.)

Montane, alpine. Woodlands, openings. Summer.
Sharkstooth Trail, July 31, 2004 and
Calico Trail, August 25, 2014.

Showy clusters of flowers top the 3 foot stems. Late summer brings on the developed seeds with their fluff of styles which carries them on the winds.

The final photograph at immediate left shows the naked receptacle after the seeds have fallen away. The receptacle is that part of the flower head to which the individual flowers are attached. You can see the scar-like marks and holes where floral parts were attached. The texture of the receptacle is sometimes a characteristic that helps identify a species.

Montane, alpine. Woodlands, openings. Summer.
Kilpacker Trail, July 22, 2004.

Montane, alpine. Woodlands, openings. Summer.
Wildcat Trail, July 12, 2010 and
Lake Hope Trail, August 11, 2014.

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

Range map for Senecio serra

Range map for Senecio triangularis