lacecap

Lacecap refers to a form of inflorescence used to describe certain hydrangea flowers, most notably those of Hydrangea macrophylla. In a lacecap inflorescence, a ring of large, showy sterile florets surrounds a center of much smaller, fertile florets, giving a delicate, lace-like appearance. This contrasts with mophead hydrangeas, which have dense heads composed mainly of large sterile florets.

The outer florets in lacecap hydrangeas are typically four-petaled and conspicuously colored, while the inner florets are tiny and less conspicuous but capable of producing seeds. Flowering generally occurs in late spring to early summer, and the overall head tends to be flat to mildly domed. The appearance can be influenced by cultivar and growing conditions, producing a range of sizes and color effects.

Care and cultivation: Lacecap hydrangeas prefer partial shade and consistently moist, well-drained soil. They tolerate a range of soils but perform best with regular moisture and protection from hot, afternoon sun. They are deciduous shrubs whose size varies by cultivar and pruning. In many cultivars, flower color is affected by soil pH and aluminum availability: acidic soils can yield blue or lavender tones, while alkaline soils tend to produce pink to red tones; some white-flowered varieties remain white regardless of soil pH. Pruning is generally done after flowering to maintain shape and vigor, as excessive pruning can reduce bloom production.

While the term is most commonly applied to hydrangeas, lacecap-like inflorescences can appear in other plant groups, though Hydrangea macrophylla lacecaps remain the best-known example.