2024 Edition • Donate • Get the App • Cite this Page
X

Colors

Data mode

Account

Login
Sign up

Support FSUS...

We've finished our 2024 fundraiser. Many thanks to those who have given! It's not too late to support us (click here)...

Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.

Key to Senecio

Copy permalink to share

1 Stems erect, usually 1, 5-24 dm tall; ray flowers absent; disk flowers white to ochroleucous or greenish, rarely pinkish; cypselae 8- to 12-ribbed.
  2 Disc florets 8-14; lower cauline leaves deltate
  2 Disc florets 18-55; lower cauline leaves hastate to deltate or lanceolate
1 Stems erect to lax, 1 or clustered, 1-12 dm tall; ray flowers absent or present; disk flowers usually yellow; cypselae usually 5-ribbed or -angled.
    3 Herbage glandular, fetid, and viscid
    3 Herbage glabrous or pubescent but not glandular, fetid, or viscid.
      4 Subshrubs; herbage glabrous; stems usually multiple, branching upwards
      4 Annual; herbage glabrous or tomentose; stems single.
        5 Ray flowers 0; calyculi bractlets black-tipped; [exotic, widespread]
        5 Ray flowers 8; calyculi bractlets not black-tipped; [natives, AR, LA, OK, TX].
          6 Plants 3-7+ dm; herbage loosely arachno-tomentose, unevenly glabrate or glabrescent; mid-stem leaves lanceolate, 3-10 cm (bases tapered or truncate, sometimes clasping)
          6 Plants 8-12 dm; herbage glabrous or glabrate; mid and upper leaves ovate to broadly lanceolate, 10-20 cm (bases clasping)