Speirantha convallarioides, false lily of the valley, is a monotypic genus — the only species in Speirantha — and an evergreen woodland groundcover native to shaded mountain forests in eastern China. Glossy, dark green, strap-shaped leaves form a low, spreading clump year-round, topped in spring by upright spikes of small, fragrant, star-shaped white flowers that recall true lily of the valley (Convallaria) at a glance, though the two aren't closely related. Unlike Convallaria, this species keeps its foliage through winter in mild climates rather than dying back to bare ground.
It spreads slowly by rhizome into a dense, weed-suppressing mat under trees and shrubs, needing rich, consistently moist, humus-heavy soil and shade — it is not reliably cold-hardy much colder than Zone 7 and struggles in hot, dry, or exposed sites. It is still uncommon in North American gardens, valued by shade-garden collectors for evergreen foliage and fragrance in a genus with no other species to compare it to.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.