Onagraceae - evening-primrose family
 

WeedsPoisonous PlantsHay Fever
Gerald A. Mulligan
Research Scientist and Research Institute Director (retired) and presently Honorary Research Associate, Agriculture and Agri-Food Canada,
Ottawa, Ontario K1A 0C6, Canada

Awarded the Lawson Medal by the Canadian Botanical Association in 2006
Read his biography "The Real Weed Man" available in print and ebook.
Epilobium angustifolium L., fireweed, épilobe à feuilles étroites
A perennial herb with stems 3 to 9 feet (9 to 27 dm.) high with vigorous underground rhizomes and racemes of showy pink to purple flowers. It has a wide circum-boreal and circum-arctic distribution. It is a native of all Canadian provinces and territories, and in all U.S. states except the southeastern states and Texas. Plants of the arctic, boreal, and cordilleran regions of Canada and Alaska have the chromosome number 2n=36, whereas plants found further south have the chromosome number 2n=72. Fireweed is a pioneer species of recently disturbed streamside and upland habitats and in logged and burned-over areas. Its beautiful flowers can turn a landscape into a sea of pink and purple. It is not considered to be a serious weed problem. Fireweed is the floral emblem of the Yukon. Southern plants of fireweed are sometimes mistaken for purple loosestrife, Lythrum salicaria L. (see photos of purple loosestrife under Lythraceae- loosestrife family).

Oenothera biennis L., yellow evening-primrose, onagre bisannuelle
Biennial, spreading by seeds; forms a flat rosette the first year; stems 2 to 6 feet (6 to 18 dm.) high; flowers yellow; throughout, but most common in the east; pastures, waste places, and roadsides; native to North America.

Click on a photo to view an enlarged image.
Weed Name Photo Weed Name Photo
fireweed, épilobe à feuilles étroites
three inflorescences
fireweed, épilobe à feuilles étroites
flowers and pods
fireweed, épilobe à feuilles étroites
(photo by Julie Mulligan)
fireweed, épilobe à feuilles étroites
fireweed, épilobe à feuilles étroites fireweed, épilobe à feuilles étroites
fireweed, épilobe à feuilles étroites
(watercolor by Lavonia R. Stockelbach, 1874-1966)
fireweed, épilobe à feuilles étroites
(photo by Sara Martin)
fireweed, épilobe à feuilles étroites
(photo by Sara Martin)
fireweed, épilobe à feuilles étroites
part of a very large stand (photo by Sara Martin)
fireweed, épilobe à feuilles étroites
part of a very large stand (photo by Sara Martin)
yellow evening-primrose, onagre bisannuelle
(flowers)
yellow evening-primrose, onagre bisannuelle
(F&M)
yellow evening-primrose, onagre bisannuelle
(winter)
yellow evening-primrose, onagre bisannuelle
(flowers and fruit)
yellow evening-primrose, onagre bisannuelle
(fruit)
yellow evening-primrose, onagre bisannuelle
(seedling)