Ontario Wildflowers website

Tall Rattlesnakeroot
Nabalus altissimus
(formerly Prenanthes altissima)

Tall Rattlesnakeroot (Nabalus altissimus) Other common names: Tall White Lettuce, Tall White Rattlesnakeroot

Other scientific names: Prenanthes altissima

French names: Prenanthe élevée

Family: Composite Family (Asteraceae)

Group: Lettuces, Prenanthes/Nabalus

Similar species:
  •   White Lettuce (Nabalus albus)

  •   Three-leaved Rattlesnakeroot (Nabalus trifoliolatus)

  •   Glaucous Rattlesnakeroot (Nabalus racemosus)


Flowers: Summer;  White, Green/Brown;  5 parts (petals)

Leaves: Alternate, Simple, Toothed

Habitat: Forests

Grows in Sun/Shade: Shade

Books: Newcomb's Wildflower Guide: 212   

Native/Non-native: Native

Origin and Meaning of Names:
 Scientific Name: altissima: tall


Photographs: 119 photographs available, of which 10 are featured on this page. SCROLL DOWN FOR PHOTOGRAPHS.

Range Map is at the bottom of the page

Tall Rattlesnakeroot (Nabalus altissimus)

Tall Rattlesnakeroot flower and flower buds.

Tall Rattlesnakeroot (Nabalus altissimus)

Tall Rattlesnakeroot flowers are greenish-white.

Tall Rattlesnakeroot (Nabalus altissimus)

Ripe Tall Rattlesnakeroot seeds dispersing.

Tall Rattlesnakeroot (Nabalus altissimus)

Tall Rattlesnakeroot (Nabalus altissimus)

The laves of Tall Rattlesnakeroot are highly variable, as with most Prenanthes/Nabalus.

Tall Rattlesnakeroot (Nabalus altissimus)

More Tall Rattlesnakeroot leaves.

Tall Rattlesnakeroot (Nabalus altissimus)

A less typical shape is shown here.

Tall Rattlesnakeroot (Nabalus altissimus)

And sometimes a triangle.

Tall Rattlesnakeroot (Nabalus altissimus)

It is best to not try to identify Prenanthes/Nabalus by their leaves!

Tall Rattlesnakeroot (Nabalus altissimus)

An entire Tall Rattlesnakeroot plant.


Range map for Tall Rattlesnakeroot (Nabalus altissimus)

PLEASE NOTE: A coloured Province or State means this species occurs somewhere in that Province/State.
The entire Province/State is coloured, regardless of where in that Province/State it occurs.

(Range map provided courtesy of the USDA website and is displayed here in accordance with their Policies)