Compositae

  • Rudbeckia occidentals / western coneflower

    Rudbeckia occidentals / western coneflower

    • dark cone-shaped flower head - like a sunflower without petals
    • ring of yellow "bumps" visible during pollination time
    • "cones" about 1" but double that when in seed.
    • usually a tall plant with sunflower-like leaves
    • alternate (not opposite) leaves
  • Senecio integerrimus / tall western groundsel

    Senecio integerrimus / tall western groundsel

    • early spring to early summer, often with larkspur
    • bright yellow flower head with several, disheveled looking blossoms
    • only 5-13 ray florets (petals)
    • cobwebby hairy basal leaves, especially when young
    • seasonally moist areas, from sagebrush to higher parts of the fen
  • Senecio triangularis  / arrowleaf ragwort

    Senecio triangularis / arrowleaf ragwort

    • leafy stems with arrow-shaped, coarse-toothed leaves
    • often in large patches on moist soil
    • clusters of yellow flower heads, each with 8-ish untidy ray florets
    • numerous green involucral bracts, sometimes with black tips
    • largest leaves occur mid-stem
  • Solidago canadensis / goldenrod

    Solidago canadensis / goldenrod

    • large sprays of yellow flowers in late summer and fall
    • often tall and in large colonies
    • lance-shaped, toothed leaves
    • mostly (but not always) in disturbed areas
  • Solidago missouriensis / Missouri goldenrod

    Solidago missouriensis / Missouri goldenrod

    • perennial herb, up to 40" tall
    • inflorescence is a branching panicle with many (≥200) yellow flower heads
    • involucres are ¼ long with 3 or 4 layers of narrow, pointed, hairless, yellow-green bracts
    • leaves are thin and lanceolate, upright and rigid with prominent midribs
    • upper leaves have pronounced but small teeth
  • Solidago multiradiata / alpine goldenrod

    Solidago multiradiata / alpine goldenrod

    • the only (?) goldenrod at alpine altitudes
    • clusters of 5-100 small, yellow composite flowers with a dozen-ish rays and 3 doz disc florets
    • medium green lance/spoon shaped leaves, bigger at base of the plants; toothed/hairy edges
  • Sonchus arvensis / field sowthistle

    Sonchus arvensis / field sowthistle

    • yellow dandelion-like
    • multiple flowers per stalk
    • often in patches in wet fields
    • leaves spiney but without lobes, clasping the stems
    • often several stems from a single point at the soil level
  • Stenotus acaulis / stemless goldenweed

    Stenotus acaulis / stemless goldenweed

    • very short, mat forming perennial yellow "daisy"
    • thin, lance-shaped leaves, pointing upward
    • yellow flower head with 6-15 ray florets, up to 50 disk florets
    • in dry, rocky, open-scrub habitats
  • Tanacetum vulgare / tansy

    Tanacetum vulgare / tansy

    • yellow, somewhat flattened, button-like flowers
    • pretty clearly in the aster family
    • camphor-ish smell
    • finely divided, fern-like compound leaves
  • Taraxacum officinale / dandelion

    Taraxacum officinale / dandelion

    • rosette growth habit with lobed leaves
    • yellow dandelion-like flowers - composites with only ray florets
    • only one flower head per stem
    • characteristic puff-ball seedheads
    • found anywhere and anytime
  • Tetradymia canescens / spineless horsebrush

    Tetradymia canescens / spineless horsebrush

    • shrub - up to 3 feet tall and across; round
    • small, yellow composite flowers in clusters of 4 to 8
    • dandelion-like seeds often present with flowers
    • primary leaves short and linear; long-lived
    • secondary leaves in axils of primaries are short-lived
    • primary leaves are not spines
  • Tragopogon spp. / salsify

    Tragopogon spp. / salsify

    • large yellow inflorescence with pointy sepals extending past the "flower"
    • grass-like leaves
    • non-native, weed
    • widespread