21. A 2004 Illinois conservation assessment listed " Helianthus silphioides " as critically imperiled within the state. 22. Lobelias, Helianthus shrumosis ( which is called the woodland sunflower ) and graceful Japanese Kirengeshoma are worth planting. 23. Native Americans domesticated the wild perennial sunflower " Helianthus tuberosus " by selecting individuals with larger tubers. 24. "Helianthus arizonensis " is a perennial herb up to 30 cm ( 12 inches ) tall. 25. "Helianthus carnosus " is a perennial herb up to 60 cm ( 2 feet ) tall. 26. "Helianthus longifolius " is a perennial herb up to 30 cm ( 1 foot ) tall. 27. "Helianthus simulans " grows in wet, mucky soils in marshes, ditches, and roadsides. 28. "Helianthus smithii " grows in wet, mucky soils in marshes, ditches, and roadsides. 29. There are 82 species of sunflowers ( genus " Helianthus " ), all native to North America. 30. "Helianthus exilis " is an erect annual reaching heights over a meter ( 40 inches ) ).
