Prenanthes alata (Hook.) D. Dietr.
western rattlesnake-root (western rattlesnakeroot)
Asteraceae (Aster family)
Introduction to Vascular Plants
western rattlesnake-root (western rattlesnakeroot)
Asteraceae (Aster family)
Introduction to Vascular Plants
Species Information
General:
Perennial herb from a slightly thickened taproot; stems erect, solitary, branched above, long-hairy, exuding milky juice when broken, 15-80 cm tall.
Leaves:
Basal leaves arrowhead-shaped, long stalked, blades irregularly toothed, glabrous, 3.5-17 cm long, 0.5-11 cm wide; stem leaves similar below, middle and lower ones with winged stalks, becoming short-stalked or unstalked, reduced upwards.
Flowers:
Heads with strap-shaped flowers, numerous in an open or round-topped inflorescence; involucres 10-13 mm tall; involucral bracts lance-oblong, the principal ones about 8, sparsely long-hairy; ray flowers white or sometimes pinkish.
Fruits:
Achenes finely lined between the nerves, cylindric or tapering to the summit, glabrous, 4-6 mm long; pappus of brownish hairlike bristles.
Illustration
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Ecology
Ecological Framework for Prenanthes alata
The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)
The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)
| Site Information |
Value / Class |
||
|
Avg |
Min |
Max |
|
| Elevation
(metres) |
362 | 0 | 1835 |
| Slope
Gradient (%) |
21 | 0 | 150 |
|
Aspect (degrees) |
286 | 0 | 360 |
| Soil
Moisture Regime (SMR) [0 - very xeric; 4 - mesic; 8 - hydric] |
4 | 1 | 7 |
| Modal
Nutrient Regime
Class |
D | ||
| #
of field plots species was recorded in: |
274 | ||
| Modal
BEC Zone Class |
CWH | ||
|
All BEC Zones (# of stations/zone) species was recorded in |
BWBS(1), CWH(202), ESSF(12), ICH(21), MH(12), SBS(20) | ||
|
Source:
Klinkenberg 2013
|
|||
Habitat and Range
Moist forests and streambanks in the lowland and montane zones; infrequent in BC S of 56degreeN; N to AK, E to AB and S to OR.Status Information
Synonyms
Synonyms and Alternate Names:
Prenanthes alata var. sagittata A. Gray
Prenanthes lessingii Hultén