Arrowleaf Ragwort

Senecio triangularis

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Asteraceae
Genus:
Senecio
Species:
Senecio triangularis

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb , Subshrub
Height:
6-8 ft
Light Requirements:
Part Shade
Drought Tolerance:
High
Bloom Months:
jun, jul, aug, sep
Bloom Colors:
Yellow

Native Range

United States: Alaska, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, Wyoming, Canada: Alberta, British Columbia, Northwest Territories, Yukon

Keystone Species Ranking

Bee Keystone:
★★☆☆☆ Based on number of native bee species using this genus for pollen and nectar (Source: National Wildlife Federation)

Host Plant for Caterpillars

Caloreas augustella, Palla (Charidryas palla)

Reported Fauna Sightings

Bees: Black-tailed bumble bee (Bombus melanopygus), Black-tailed bumble bee (Bombus melanopygus), Fernald cuckoo bumble bee (Bombus flavidus), Fernald cuckoo bumble bee (Bombus flavidus), Forest bumble bee (Bombus sylvicola), Forest bumble bee (Bombus sylvicola), Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), Half-black bumble bee (Bombus vagans), Half-black bumble bee (Bombus vagans), Indiscriminate cuckoo bumble bee (Bombus insularis), Indiscriminate cuckoo bumble bee (Bombus insularis), Sitka bumble bee (Bombus sitkensis), Sitka bumble bee (Bombus sitkensis), Two-form bumble bee (Bombus bifarius), Two-form bumble bee (Bombus bifarius), van Dyke bumble bee (Bombus vandykei), van Dyke bumble bee (Bombus vandykei), Western bumble bee (Bombus occidentalis), Western bumble bee (Bombus occidentalis), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons), Yellow-faced bumble bee (Bombus vosnesenskii), Yellow-faced bumble bee (Bombus vosnesenskii)

Soil Requirements

Soil Type:
moist, rich, well-drained loamy soil
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
good drainage preferred
Moisture:
consistently moist
Notes:
Commonly found near streams and wet meadows

Germination Information

Pre-treatment: 6-month cold moist chilling in a refrigerator maintained at 34 to 37°F or 5 month outdoor cold, moist stratification.

Establishment: This species is very responsive to decreasing light intensity with mean germination decreasing under partial and zero irradiance. There were also slight increases in seedling mortality from full irradiance to partial and zero irradiance. No appreciable gains in germination occurred after exposing the partial and zero irradiance groups to a secondary full irradiance. One protocol reported no germination, which conflicts with the other protocols.

Source: npn.rngr.net