Spermacoce spp.
false buttonweeds
Pantropical: warm regions of the Americas, Africa, Asia, and Australia
Overview
Spermacoce spp. is a genus of about 275 species of herbs and subshrubs in the madder family, Rubiaceae, spread through the warmer regions of the Americas, Africa, Asia, and Australia. The four-angled stems carry opposite, narrow leaves joined at the base by a fringed stipular sheath, and dense, button-like clusters of tiny four-lobed white to pale flowers sit in the leaf axils. Plants range from low, sprawling herbs to upright subshrubs from 4 to 32 inches (10-80 cm) tall. Many species are fast-growing colonizers of disturbed, sandy ground, and several rank as agricultural weeds that spread quickly by seed. Their short life and ready self-seeding are the main constraints in cultivation.
Native Range
Native across the tropics and subtropics of the Americas, Africa, Asia, and Australia, with several species native to the southeastern United States. Plants grow on roadsides, sandy flats, fields, and other open, disturbed ground.Suggested Uses
Occasionally grown as an informal filler or ground cover in warm-climate and naturalistic plantings. More often the genus is encountered as a wild plant of roadsides, sandy flats, and cultivated fields.How to Identify
Appearance
Size & Dimensions
Height4" - 2'8"
Width/Spread4" - 1'8"
Bloom Information
Small white to pale flowers appear through the warm months, summer into autumn in temperate areas and much of the year in the tropics, held in dense clusters in the leaf axils. Flowering and seeding overlap, so plants often carry open flowers and ripe capsules at the same time.
Detailed Descriptions
Flower Description
white to pale pink or blueFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 6-8 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
Time to Maturity
Flowers within one season
Care & Maintenance
Care Guide
Spermacoce spp. grows in full sun in average to sandy, free-draining soil and tolerates poor, dry ground. Moderate water suits it, though established plants endure drought. Frost ends the annual species, while perennial kinds regrow in frost-free zones 9-11. No feeding is needed, and rich soil mainly adds leafy growth. Plants self-seed freely and can spread well beyond where they were placed.Pruning
Little pruning is needed. Spent plants can be sheared or pulled to limit self-seeding before the capsules ripen. Perennial species are cut back in early spring to refresh the clump.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons