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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 Urticaceae

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1 Plant a tree; petiole attachment to leaf blade peltate; leaves alternate; [tribe Cecropieae]
1 Plant an herb; petiole attachment to leaf blade marginal; leaves alternate or opposite.
  2 Leaves opposite.
    3 Plant with stinging trichomes, these having a distinct bulbous or cylindrical base, and a stiff, translucent apex; [tribe Urticeae]
    3 Plant without stinging trichomes (or these minute and not apparent), the non-stinging hairs (if present) soft and flexible, lacking a bulbous or cylindrical base.
      4 Flowers in axillary spikes; foliage dull, yellow-green; leaves 3-veined from the base, the 2 main side veins reaching the margin about 2/3s of the way from blade base to blade tip, the midvein with 1-2 or more prominent secondary veins borne near or past the midpoint and at a sharply acute angle to the midvein, these arching to the leaf margin; [tribe Boehmerieae]
      4 Flowers in axillary panicles or fascicles; foliage shiny, bright green; leaves 3-veined from the base, the 2 main side veins extending to the apex of the blade, the midvein with many secondary veins borne along its length at a nearly right angle, and connecting to the 2 main side veins rather than reaching the leaf margin; [tribe Lecantheae]
  2 Leaves alternate (at least above, if not throughout).
        5 Leaves toothed; plant either with or without stinging trichomes.
          6 Flowers in axillary spikes; woody herb to 4 m tall, without stinging trichomes; leaf undersurfaces white-pubescent; [tribe Boehmerieae]
          6 Flowers in terminal or axillary panicles; herb to 1.5 m tall, with stinging trichomes; leaf undersurfaces green; [tribe Urticeae]
        5 Leaves entire; plants without stinging trichomes.
             7 Stipules absent; [tribe Parietarieae]