SafePlants

Calycoseris wrightii - White Tackstem

Calycoseris wrightii, commonly known as White Tackstem, is a charming annual wildflower that graces the southwestern landscapes of the United States.

Taxonomy and Nomenclature

• Scientific Name: Calycoseris wrightii A. Gray
• Common Name: White Tackstem
• Family: Asteraceae (Sunflower family)
• Synonyms: s text

Considerations for Pets

• The stems below the flower have tack-like glands.

Considerations for Children

• The stems below the flower have tack-like glands.

Distribution and Habitat

White Tackstem is native to the southwestern United States, particularly Arizona and California. It thrives in desert environments and blooms after winter rains.

Morphological Characteristics

• It is an annual spring wildflower.
• It grows as an erect, branching annual up to about 1 foot high.
• The ligules (ray florets) are white, often with fine reddish veins on the abaxial (lower) side, measuring 2-3 cm long.
• The involucres (a collection of bracts surrounding the flower head) are 10-15 mm in size.
• The stems, distal branches, and phyllaries (individual bracts of the involucre) are gland-dotted with straw-colored glands.
• Mostly basal leaves divided.
• Flowers white to 1.5" wide with pink stripes on back of petals.

Quirky Facts

• The stems below the flower have tack-like glands.
• White Tackstem is one of only two species in the genus Calycoseris.
• The flower petals sometimes exhibit candy-stripes on their underside.

Ecology

White Tackstem is a native Southwestern desert plant that blooms after plentiful winter rains.

Further Resources

• Discover Life: Provides information about the biology, natural history, ecology, identification, and distribution of Calycoseris wrightii.
• Lady Bird Johnson Wildflower Center: Focuses on protecting and preserving North America's native plants.
• Weather Underground: Provides weather forecasts and reports, which can be relevant to understanding the blooming conditions of White Tackstem.