About Eriocapitella japonica (Thunb.) Nakai
Eriocapitella japonica (Thunb.) Nakai is a perennial herbaceous plant that grows 60 to 90 cm (2 to 3 ft) tall. All plant parts are soft, downy, and covered in short hairs. Its basal leaves are ternate, lobed, and toothed. The inflorescence is a cyme, with flower stalks emerging from a whorl of leaves wrapped around the top of the stem. Each flower measures approximately 5 to 7.5 cm (2.0 to 3.0 in) across, and has 1–3 whorls of sepals (with no petals) and yellow stamens. The sepals are colored rosy purple or carmine. The fruits are silky achenes. This species is native to Central China, East China, South China, Taiwan, and Vietnam. It has been cultivated and naturalized in multiple Chinese provinces: Anhui, Jiangsu, Jiangxi, Zhejiang, and Fujian in East China; Guangdong in South China; and Yunnan in Southwest China. It was introduced to Japan and Korea, and has been naturalized in Japan for hundreds of years. Alongside four other taxa – Eriocapitella hupehensis, Eriocapitella vitifolia, Eriocapitella tomentosa, and Eriocapitella × hybrida – this species is classified as a fall-blooming anemone. Just like E. hupehensis, E. japonica flowers from July to October in its native habitat. Varieties of Eriocapitella japonica are cultivated across the world, particularly in China, Japan, and Korea, where naturalized populations occur. Hundreds of years ago, a form of E. hupehensis with smaller, semi-double pink-sepaled flowers escaped cultivation and spread across China to Japan and Korea. In 1843, plant explorer Robert Fortune found this form in a Shanghai graveyard and sent it to England, where it became known as E. japonica, the Japanese anemone. European horticulturists crossed this Japanese anemone with E. vitifolia to create cultivars of the artificial hybrid E. × hybrida. Beginning in 1998, Rudy conducted 5 years of experiments with 26 cultivars of fall-blooming anemones at the Chicago Botanic Garden. Four of the tested cultivars were E. japonica; one of these, E. japonica 'Prinz Heinrich', had the longest bloom length of any cultivar, at 65 days. As of March 2020, two E. japonica cultivars – 'Pamina' and 'Rotkäppchen' – hold the Royal Horticultural Society's Award of Garden Merit (AGM). The cultivar 'Prinz Heinrich' was removed from the AGM list in 2013.