Mrs. Robb's Bonnet

Euphorbia amygdaloides subsp. robbiae (yoo-FOR-bee-ah am-ig-duh-LO-id-eez ro-bee-AY)

Family: Euphorbiaceae Unknown Herbaceous (1-3 ft)

Mrs. Robb's Hatbox is a subspecies of Euphorbia amygdaloides and is also known as wood spurge. The subspecies robbiae differs from the species by having rosettes of broad, dark green leaves and a more rapid rhizomatous spread. The rapid spread makes this subspecies an excellent ground cover, but it can spread too much and outgrow its allotted space. The subspecies name, robbiae , is in honor of a botanist and plant collector, Mary Ann Robb. She discovered this plant near Istanbul, Turkey in 1891 and brought cuttings and seeds of this plant back to her home in Liphook, Hampshire. The common name references the fact that she used her hatbox to transport the seeds and cuttings home. The specific epithet, amygdaloides , originates from the Latin word, amygdalinu s and means "almond-like." Mrs. Robb's Hatbox grows best in dry to medium moist, loose, well-drained soils in full sun to partial shade. If the soil is wet, especially in winter, the plant can die. It prefers afternoon shade if your site includes hot summer days, but if there is too much shade, the attractively shaped clumps can open up. It also tolerates poor soils, including rocky-sandy soils. This plant can be propagated by division in the spring, and it will also self-seed in the garden unless spent flowers are deadheaded before the flowers set seeds. This fast-growing, evergreen perennial shrub grows 1 to 2 feet tall and 2 to 2.5 feet wide. It forms a dense carpet of rosettes in colonies of shiny, deep green, spatulate to obovate leaves and showy, lime-green bracts with a small cluster of apetalous flowers. The plant is rhizomatous, producing new plants from underground runners, and is often used as a ground cover. When planting, space the plants 18 inches apart to prevent overcrowding. Mrs. Robb's hatbox may be used as a ground cover in flower beds, borders, cottage gardens, or coastal gardens. Diseases, Insects, and Other Plant Problems: A native of Mediterranean-type climates, the plant may show stress in hot and humid summers of North Carolina. It is a highly pest resistant species. Overwatering can cause root rot. All parts of this plant are toxic if ingested. Keep the plant out of the reach of small children and pets. Use protective gloves and eyewear when handling this plant to avoid contact with the toxic sap. VIDEO Created by Laura Barth for "Houseplants, Succulents, and Cacti," a plant identification course offered in partnership with Longwood Gardens. More information on Euphorbia .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 66 attributes.