Parthenice mollis – Annual Monsterwort

Parthenice mollis - Annual Monsterwort (flowers)

Parthenice mollis - Annual Monsterwort

Parthenice mollis - Annual Monsterwort (leaves)

Parthenice mollis - Annual Monsterwort

Plant Name

Scientific Name: Parthenice mollis

Common Name: Annual Monsterwort

Plant Characteristics

Duration: Annual

Growth Habit: Herb/Forb

Arizona Native Status: Native

Habitat: Desert, Upland. This plant grows in desert washes, on slopes, and along roadsides.

Flower Color: Green

Flowering Season: Summer, Fall. It blooms after the summer monsoon rains have begun.

Height: Up to 4 to 6 feet (1.2 to 1.8 m) tall

Description: The light green, finely-haired, rayless flower heads have tiny, yellowish disk flowers and drooping flower stalks. The flowers are followed by hairless cypselae (seeds). The leaves have 3 pale green main veins and are grayish green in color, alternate, egg-shaped, petioled, variably toothed and/or shallowly lobed, progressively smaller toward the stem tips, up to 10 inches (25 cm) long near the base of the plant, and covered in short, fine hair like the rest of the plant. The stems are green, finely-haired, erect, and well-branched above. The mature plants are large and conspicuous and often appear to have wilted lower leaves.

Special Characteristics

Allergenic – The flower pollen is a moderate allergen.

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: Parthenice A. Gray – parthenice
Species: Parthenice mollis A. Gray – annual monsterwort

More About This Plant

Arizona County Distribution Map