© Shang-Kwei Wang, some rights reserved (CC-BY-NC) · iNaturalist
Overview
Cyanthillium is a genus of about five annual and short-lived perennial herbs in the daisy family, native to tropical Africa and Asia and now spread through warm regions worldwide as a weed. The most common species, C. cinereum, the little ironweed, forms an erect, branching plant 6-28 inches (15-70 cm) tall with thin stems and small, alternate, greyish-green leaves. Numerous small flower heads, each about 0.2-0.3 inch (5-8 mm) across, carry pinkish-mauve to purple disc florets and open over much of the year in warm climates. Each head matures into a tuft of soft white pappus that carries the small seeds on the wind. The genus grows on disturbed ground, roadsides, fields, and waste places on a wide range of soils, behaving as a fast-cycling pioneer and crop weed. C. cinereum is used in traditional medicine across Africa and Asia. As short-lived warm-climate plants, these herbs are killed by frost and complete their cycle quickly, renewing entirely from abundant wind-blown seed.
Native Range
Cyanthillium is native to tropical Africa and tropical Asia. C. cinereum has spread as a weed through the tropics and subtropics of the Americas, Australia, and the Pacific, growing on disturbed and cultivated ground.Suggested Uses
Cyanthillium is rarely grown by choice and is encountered mostly as a weed of fields, gardens, and roadsides. C. cinereum is gathered for use in traditional herbal medicine across parts of Africa and Asia. The flowers are a minor nectar source for small bees and butterflies in warm regions.How to Identify
Appearance
Size & Dimensions
Height6" - 2'4"
Width/Spread4" - 1'
Bloom Information
In warm climates Cyanthillium flowers over much of the year, with peaks in the wet season and after rain. The small purple flower heads open in loose clusters and quickly convert to wind-borne seed. In areas with cold winters, flowering is limited to the frost-free months.
Detailed Descriptions
Flower Description
pinkish-mauve to purpleFoliage Description
greyish-greenGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established