References

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

Colors

Light mode. White background and dark text. Dark mode. Dark background and light text, for low light situations or preference. High contrast mode. Very dark background and very bright yellow text. For bright outdoor light and accessibility.

Data mode

Data light. Don't show photos automatically, e.g., spotty cell connection. Data not limited. Show all photos by default.

Account

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)...

2024 has been a banner year for making the best flora we can imagine. We've created:

Keys with embedded images of diagnostic features
Clickable glossary terms with illustrated definitions
FloraQuest: Carolinas & Georgia mobile app
Heliophily and Wetland Statuses
Direct links to Flora of North America
17,730 new high quality diagnostic photos and counting

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:

Donate $15 per month
(0.9¢/key)

Donate $30 per month
(1.8¢/key)

Donate $50 per month
(amazing!)

Donate another
or one-time amount

For Tridax

Powell, A.M. 1965. Taxonomy of Tridax (Compositae). Brittonia 17: 47-96. Google Scholar

Strother, J.L. 2006xx. Tridax. In Flora of North America Editorial Committee. 2006c. Flora of North America north of Mexico. Volume 21, Magnoliophyta: Asteridae, part 6: Asteraceae, part 3. Oxford Univ. Press, New York, NY. 616 pp. Google Scholar

Request PDF | Donate | Contact Us
Website by M.T. Lee
beta version 2025-01-07