Conyza canadensis – Canadian Horseweed

Conyza canadensis - Canadian Horseweed, Marestail, Mare's Tail, Horseweed Fleabane, Canada Fleabane

Conyza canadensis - Canadian Horseweed, Marestail, Mare's Tail, Horseweed Fleabane, Canada Fleabane

Plant Name

Scientific Name: Conyza canadensis

Common Names: Canadian Horseweed, Marestail, Mare's Tail, Horseweed Fleabane, Canada Fleabane

Plant Characteristics

Duration: Annual, Biennial

Growth Habit: Herb/Forb

Arizona Native Status: Native

Habitat: Desert, Upland, Riparian

Flower Color: Dull white rays and yellow disks

Flowering Season: Summer

Height: To 5 feet (1.5 m) tall

Description: The tiny flower heads are at the branch tips of a highly branched flower stalk. The individual flower heads have yellow disk flowers that are almost hidden among the slender, white rays. The flowers are followed by fuzzy seed heads with a tan to whitish pappus. The leaves are green, hairy, narrow, alternate, mostly linear, and crowded along the main stem. This tall, upright weed resembles a green horse's tail and is unbranched below and highly branched above.

Special Characteristics

Allergenic – Skin contact with the foliage may cause contact dermatitis in susceptible persons.

Edible – The young leaves and seedlings are edible if cooked and can be used as flavorings in other foods.

Classification

Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Asteridae
Order: Asterales
Family: Asteraceae – Aster family
Genus: Conyza Less. – horseweed
Species: Conyza canadensis (L.) Cronquist – Canadian horseweed

More About This Plant

Arizona County Distribution Map