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Support the Flora of the Southeastern US

2024 has been a banner year for making the best flora we can imagine. We've created:
With financial support from people like you, we are aiming even higher in 2025. Together we can accomplish all this: Vote on our 2025 priorities
  • Add Global Conservation Ranks (GRanks) vote
  • Professional graphic keys (polyclaves) to individual families/genera vote
  • 2 new FloraQuest apps: Florida & Mid-South vote
  • Image overlays highlighting diagnostic characters with arrows vote
  • iNaturalist integration in FloraQuest vote
Write-in vote: vote
We've set a goal of recruiting 200 ongoing supporters to donate $15 or more each month in 2025. Please help us reach this goal and make next year's flora even better:

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 Orobanchaceae

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1 Plants lacking chlorophyll (holoparasitic), with foliage and stems variously pink, purple, brown, tan, orange, or white.
  2 Stem paniculately branched; flowers dimorphic, those low in the inflorescences small, pistillate, and fertile, those high in the inflorescence larger, apparently perfect but functionally staminate; [tribe Orobancheae]
  2 Stem simple (rarely few-branched); flowers all alike.
    3 Calyx deeply cleft on the lower side; stamens exserted; [tribe Rhinantheae]
    3 Calyx either nearly regular, or deeply cleft above and below into 2 lateral halves; stamens included; [tribe Orobancheae].
      4 Flowers solitary on a long pedicel (appearing as a scape, the true stem entirely underground or nearly so)
      4 Flowers several-many, sessile or subsessile in a dense spike.
        5 Calyx 5-lobed, the lobes subequal, all well-developed
        5 Calyx 2-4-lobed, rarely 5-lobed, but then the fifth lobe minute and much smaller than the other lobes.
          6 Calyx divided to the base into 2 lateral halves, these usually 2-lobed, the 4 lobes long-attenuate or caudate; stem unbranched
          6 Calyx tubular, with 4 (-5) lobes about the length of the calyx tube; stem branched (except in depauperate individuals)
1 Plants with chlorophyll (hemiparasitic), with foliage and stems normally green.
             7 Stem leaves alternate.
               8 Leaves entire or 3-5-lobed at the tip.
                 9 Bracts subtending flowers orange, red, or yellow; calyx 4-lobed; capsule loculicidal; pedicel lacking bracteoles; seeds broad, wingless; [tribe Castillejeae]
                 9 Bracts subtending flowers green; calyx 5-lobed; capsule septicidal and tardily also loculicidal; pedicel with 2 bracteoles; seeds narrow, winged; [tribe Cymbarieae]
             7 Stem leaves (at least the lower) opposite.
                     11 Plant strict, unbranched unless damaged; flowers in a terminal spike; corolla purple; [native, sometimes weedy]
                     11 Plant strongly branched; flowers solitary and axillary; corolla red or orange; [exotic, in agricultural fields]
                       12 Calyx 4-lobed or essentially unlobed; corolla strongly bilabiate, the upper lip consisting of 2 petals almost wholly connate and strongly cucullate (hooded); corolla white or yellow; [tribe Rhinantheae].
                          13 Stem leaves pinnately lobed, the lobes rounded and themselves crenate; perennial, 3-8 dm tall
                          13 Stem leaves either toothed with acuminate teeth, or entire (bracteal leaves in and near the inflorescence sometimes pectinately fringed); annual, 1-4 dm tall
                            14 Stem leaves entire (bracteal leaves in and near the inflorescence sometimes pectinately fringed); seeds 1-4 per capsule
                       12 Calyx 5-lobed; corolla 5-lobed, the lobes relatively similar in size and shape, spreading; corolla yellow, orange, red, or pink; [tribe Gerardieae].
                              15 Corolla pink; leaves linear and thread-like (except lanceolate in A. auriculata)
                              15 Corolla yellow or orange; leaves either lanceolate or broader, at least the basal pinnately or bipinnately lobed or toothed, or pinnately or bipinnately divided into linear segments.
                                16 Leaves pinnately or bipinnately divided into linear segments up to 2 mm wide; corolla rotate, the tube shorter than the lobes
                                16 Leaves not lobed or divided, or the segments broader; corolla tubular, campanulate, or funnelform, the tube much longer than the lobes.
                                  17 Corolla orange, tubular, the tube narrow and straight, > 5× as long as the diameter