General:
Biennial or short-lived perennial herb from a taproot and often a stout, branched stem-base; stems erect, several, branched, glabrous, 10 to 100 cm tall.

Leaves:
Basal leaves soon deciduous; stem leaves alternate, closely and evenly toothed or entire, hairless, middle and upper mostly clasping, often sticky with resin.

Flowers:
Heads with ray and disk flowers, solitary or in a flat-topped cluster; ray flowers yellow, 25-40, 7-15 mm long; involucres 1-9 mm tall; involucral bracts strongly resinous, regularly graduated, the green tips reflexed.

Fruits:
Achenes nerved, usually squared off at the tip, glabrous, 2-3 mm long; pappus of several slender awns.

Notes:
Three weakly defined varieties occur in BC and may be separated as follows:

1. Leaves entire or remotely toothed, the lower ones often irregularly toothed or somewhat pinnately cut.................... var. quasiperennis Lunell

1. Leaves closely and evenly toothed. 2. Upper and middle leaves 2-4 times as long as wide, mostly egg-shaped or oblong..................... var. squarrosa

2. Upper and middle leaves 5-8 times as long as wide, mostly linear-oblong to lanceolate.................. var. serrulata (Rydb.) Steyerm.

Source:  The Illustrated Flora of British Columbia