Gillenia trifoliata

Gillenia trifoliata, also known as three-leaved gillenia or three-leaved spirea, is a perennial plant of the forest floor that is infinitely graceful. It has an elegant stature. From early summer, it is adorned with tiny but countless white star-shaped flowers with red calyxes, which persist on their purple stems for a long time. Before bidding farewell in autumn, its lovely foliage, which is divided into 3 leaflets, takes on fiery hues. Delicate and ethereal, it beautifies shaded areas, even in the roots of trees. In the garden, it only fears limestone soils and excessively dry conditions. The three-leaved spirea pairs well with Solomon's seal, astilbes, barrenworts, and all plants that thrive in ericaceous soil, in semi-shade. 

Gillenia trifoliata (synonym Porteranthus trifoliatus) is a perennial herbaceous plant with a rhizomatous rootstock. It belongs to the Rosaceae family, and is a cousin of spireas, brambles, and roses. It is native to mountainous areas of North America, where it often grows on the edge of forests, in a thick layer of humus. It takes a little while to establish, but within 4 to 5 years it forms a rounded mass that reaches an average height of 1.1m (4ft) and a width of 70cm (28in). The plant spreads laterally through its rhizomes. In spring, woody, slender, and branched yellow to purple stems emerge from the ground. They bear deciduous leaves divided into 3 ovate, pointed, and finely dentate leaflets. The foliage is a shade of matte dark green, taking on sumptuous orange hues in autumn before falling.

The flowering occurs in May-June and can continue until August depending on the climate. The pure white star-shaped flowers are carried by thin reddish stems, well above the foliage. Measuring 2 to 3cm (1in) long, they consist of 5 slender petals that are very pale-pink when they bloom, quickly turning white. The reddish calyxes at the base of the flowers persist on the plant after the petals have fallen. This nectar-bearing flowering attracts numerous pollinating insects as well as certain birds. Occasionally, decorative mahogany-coloured fruits form and last late into the season. The stems die in winter and should be pruned in spring when vegetation resumes.

With its graceful appearance, Gillenia trifoliata stands out in flower beds, away from the scorching sun. It is best planted on the edge of a grove or near a hedge, where it will tolerate root competition and appreciate soil covered with decomposing leaf litter. It pairs well with all sorts of woodland plants, such as bearded irises, Solomon's seal, lily-of-the-valley, fairy bells, Phaeum geraniums, Salvia sylvestris, Brunnera, and many others. Its ethereal flowering complements those of rhododendrons, hydrangeas, and azaleas in acidic soil. Its combination with purple heucheras is fantastic.