Trillium recurvatum

Trillium recurvatum is a perennial plant with rhizomes, native to Missouri and Mississippi where it decorates the undergrowth and banks of rivers in a rather unique way in springtime. This Trillium gets its species name, recurvatum, from the recurved sepals that support its upright reddish-brown flower. Underneath the flowering, there are 3 often maculated light green leaves, very decorative when the plant spreads in colonies. American trilliums, quite rare in cultivation, definitely deserve to be tried in shaded and cool areas of our gardens. They are a little slow to establish but they withstand our winters perfectly and eventually form unusual spring carpets in a wooded garden.

Trillium recurvatum, formerly classified in the Liliaceae family, now belongs to the Melanthiaceae family. It is a distant North American cousin of the fragrant Solomon's Seal that populates our European undergrowth. It is native to the southeastern United States, where it blooms in spring in the humus of deciduous undergrowth as well as along rivers, on generally limestone, cool but well-drained soil.

Trilliums are very unique plants that do not develop true stems or true leaves. The vegetation that emerges in spring is actually just a flowering, composed of an upright petiole, an extension of the rhizome, bearing a coloured flower that surmounts bracts resembling leaves. The true leaves, tiny and scale-like, are found on the flower petiole.

As a herbaceous and perennial plant, Trillium recurvatum develops in spring from a fleshy and thick underground rhizome that does not like to be disturbed. It goes into dormancy as soon as the soil dries out, during the summer or in autumn due to the cold. The plant produces short and slender leafy stems, standing at 30-40cm (12-16in) above the ground. Thanks to its rhizomes, this Trillium will slowly form small colonies occupying at least 30cm (12in) of ground. Each stem bears only 3 beautiful leaves inserted at the same level on the stem and arranged in a collar, horizontally. The leaves are narrowly ovate to elliptical in shape, with a beautiful bright green colour randomly marbled with grey and light green, especially when young. They measure about 8cm (3in) long and 5cm (2in) wide. The flowering takes place in April, lasting 2 to 3 weeks, more or less early depending on the climate, in the center of the trio of leaves. The flower, upright and narrow, 4 to 4.5cm (2in) tall, is composed of 3 narrow reddish-brown petals arched above the six black stamens that bend over the pistil. The flower, without stalks, is surmounted by 3 narrow green sepals, recurved downwards and arranged in a staggered pattern. This flowering is pollinated by beetles and flies. This species is very difficult to multiply by sowing. In Trilliums, the seeds are dispersed by ants. Plants from seeds may take several years before flowering.

A little slow to establish, this Trillium recurvatum is however faithful, lives long (25 years), and requires little care where it likes to grow. It should be planted in groups of 3 specimens in wooded areas or dappled sunlight (introduce several plants in a small area), in soil rich in humus or leaf compost that remains moist for as long as possible. It pairs well with other small perennials that thrive in similar conditions, such as Mertensia virginica with its beautiful blue spring flowers. Plants with staggered flowering or interesting foliage will fill the ground in summer while the trillium rests underground: consider, for example, Ophiopogons, saxifrages, small ferns, Asarums, hostas, etc. It can be grown in pots, but watering should be monitored. Whether in the ground or in pots, its association with Begonia grandis subsp. evansiana, which takes over after its flowering, is always successful.

The Latin name Trillium derives from the fact that the different parts of these plants are ternary: from the unique cluster of three leaves on each stem, to the construction of the flower, composed of 3 green sepals, 3 coloured petals, six stamens, and 3 fused carpels.