Spiraea micrantha Hooker f. (1878: 325)

Xiong, Xian-Hua, Liu, Chao, Pu, Yu-Qing & Liu, Mei, 2025, Rubus inopertus var. echinocalyx, R. pentagonus var. eglandulosus and Spiraea japonica var. pinnatifida, three synonyms of Rosaceae, Phytotaxa 697 (2), pp. 206-212 : 211

Spiraea micrantha Hooker f. (1878: 325)

Syntypes:— INDIA. Sikkim: 6000–8000 ft., J.D. Hooker s.n. (K!). BHUTAN. 5800–10000 ft., Griffith s.n.

≡ S. japonica Linnaeus f. (1782: 262) subsp. micrantha (Hooker f. 1878: 325) Kitamura (1974: 5) .

— S. callosa Thunberg in Murray (1784: 209) var. macrophylla Hooker & Thomson. nom. nud.

— S. japonica Linnaeus f. (1782: 262) var. pinnatifida Yu & Lu in Yu et al. (1980: 490). Type:— CHINA. Xizang: Cuona , 2900 m, 5 October 1974, Qing-Zang Exped. 74-2816 (holotype PE!; isotypes PE!, HNWP!).

Notes: — Spiraea japonica var. pinnatifida was published by Yu & Lu in Yu et al. (1980) on the basis of a collection from Xizang ( Fig. 4A ). In the protologue, the authors noted that this variety was distinguished from S. micrantha Hooker f. var. micrantha (1878: 325) by the latter's larger inflorescences and glabrous carpels. However, according to Hooker’s (1878) protologue and type specimens, the ripe carpels of S. micrantha are exposed villous. Examination of the type specimens of S. japonica var. pinnatifida showed that the ripe carpels of S. japonica var. pinnatifida also are sparsely pilose. After further comparison of the type specimens, additional specimens at hand and the protologues of S. micrantha ( Fig. 4B ) and S. japonica var. pinnatifida ( Figs. 4A & 4C–4E ), we found that they are not essentially different from each other.

Spiraea micrantha is morphologically close to S. japonica , but differs from it by the pale pink, rarely white petals and sub-dioecious sexuality ( Figs. 4C–4E ) (vs. pink or purple-red petals and bisexual flowers; Businský 2020).

Distribution:— China (Xizang), India, Bhutan and Nepal ( Grierson 1987, Alexander & Joshi 2012, Businský 2020).

Figures

FIGURE 4. Spiraea micrantha. A. Holotype of S. japonica var. pinnatifida, B. Syntype of S. micrantha, C. Flowering branchlet, D. Flowers with almost abortive pistils, E. Flowers with almost abortive stamens.