Acmella, Genus, spp., Multiple species,
- Genus
- Multiple species
spotflowers
Pantropical (centered in the Americas)
Overview
Acmella is a genus of about 30 herbs in the daisy family, Asteraceae, found across the warm regions of the world and most diverse in the Americas. Known as spotflowers, plants are low, spreading or upright annuals and short-lived perennials 8-18 inches (20-45 cm) tall, with fleshy stems that often root where they touch the ground. The flowerheads are cone- or egg-shaped, gold to yellow, and in several species carry a deep red or maroon eye at the center, the feature behind the common name. A. oleracea, grown as toothache plant, paracress, or jambu, is cultivated as a leaf vegetable and herbal remedy; chewing its leaves or flowerheads produces a tingling, numbing sensation and a flow of saliva from the compound spilanthol. Plants grow quickly in warm, moist conditions, flower over a long season, and are frost tender. Most are grown as annuals outside the tropics.
Native Range
Warm regions worldwide, with the greatest diversity in tropical and subtropical America. A. oleracea is thought to have originated in South America and is now grown across the tropics as a vegetable and herb.Suggested Uses
Acmella is grown as an edible and medicinal herb, as a low bedding and container plant for its gold red-eyed flowerheads, and as a curiosity for the tingling effect of A. oleracea. The flowers draw bees, and trailing stems spill from baskets and pots. Leaves are used as a cooked or raw vegetable in parts of the tropics.How to Identify
Appearance
Size & Dimensions
Height8" - 1'6"
Width/Spread1' - 2'
Bloom Information
Plants flower over a long warm season, from summer into autumn, and nearly year-round in frost-free climates. The gold, often red-eyed flowerheads are produced steadily and draw bees and other insects. Removing old heads keeps new ones coming and limits self-seeding.
Detailed Descriptions
Flower Description
Gold to yellow, often with a red central spotFoliage Description
GreenGrowing Conditions
Sun Requirements
Requires 5-10 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
Care & Maintenance
Care Guide
Acmella grows in full sun to light shade in moist, fertile, well-drained soil and grows fast in warm weather. Plants need steady moisture, as they wilt quickly in dry heat, and they benefit from light feeding for continuous leaf and flower production. The genus is frost tender and is grown as a warm-season annual where winters are cold, or kept as a tender perennial in roughly USDA zones 9 to 11. Stems that root as they spread can be lifted and replanted to propagate. Aphids and leaf-eating insects are the main pests.Pruning
Plants are pinched and lightly sheared to keep them bushy and to remove spent flowerheads, which prolongs bloom and limits self-seeding. Harvesting leaves and flowers of A. oleracea for use also keeps growth compact. Frost-killed plants are cleared at the end of the season.Container Growing
Suitable for container growing
Minimum container size: 2 gallons
Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
transplant
Days to Maturity
60–75 days
Plant Spacing
12 inches
