A shrub to 3 m tall. Shoot glabrous, or with scattered stiff hairs. Leaf narrowly ovate to obovate to lanceolate, 3–8 × 0.5–3 cm, base rounded, tip acute to long acuminate, sparsely pubescent beneath when young, margin entire or with 1–6 pairs of teeth; petiole 4–7 mm. Flowers April-June; inflorescence terminal with paired flowers, occasionally with extra flowers axillary to bracteoles; flowers sessile but on peduncles 0–12 mm long. Sepals 4, ovate-lanceolate to obovate. Corolla white or pink to reddish outside, 4-lobed, the lobes orbicular; tube pubescent inside. Stamens 4, included. Style as long as the corolla. Fruit August-September; achene 10–15 mm long. (Flora of China 2021).
Distribution China Hebei, Hunan, Liaoning, Nei Mongol North Korea South Korea Russia Near the Chinese border
Habitat Scrub, forests, grasslands.
USDA Hardiness Zone 5-6
RHS Hardiness Rating H6
Conservation status Not evaluated (NE)
As the (partial) list of synonyms suggests, this is a taxon of questionable extent and diversity; plants of this group are very occasionally cultivated in the west, where they tend to be subject to a similar degree of nomenclatural confusion. 1923 is sometimes cited as the taxon’s date of introduction to cultivation (Dirr 2009); more recently in the UK, Zabelia biflora was commercially available from Larch Cottage Nurseries until 2018 (Royal Horticultural Society 2020). Michael Dirr observed a plant flowering in the Arnold Arboretum in Massachusetts in 1991 (Dirr 2009), while a 2003 accession at Longwood Gardens in Pennsylvania was obtained from the Princeton Nurseries in New Jersey (presumably before the nurseries’ closure in 1995) (Royal Botanic Garden Edinburgh 2021). However, an online (photograph) of a plant purporting to be Z. biflora, apparently taken in the Michigan area, clearly shows Z. tyaihyoni, as do (photographs) of a plant presumably grown as Z. biflora in the University of Wroclaw Botanical Garden in Poland. This species may well be even hardier than its traditionally assessed limit of USDA zone 5–6 may imply.