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| Lysimachia longiracemosa Y.H.Tan & Z.X.Ma, in Ma, Quan et Tan. 2026. |
Abstract
Lysimachia longiracemosa, a new species of Primulaceae, is described from the margin of highland subtropical broad-leaved forests in southeastern Yunnan, China. Based on morphological evidence, the new species is placed in Lysimachia subgenus Idiophyton and diagnosed against its closest congener, L. nutantiflora. A revised key is also provided to distinguish L. longiracemosa from the related frutescent species with racemose inflorescences of the Lysimachia subgenus Idiophyton.
Keyword: Flora of China, Linnean, Lysimachia nutantiflora, Lysimachia subgenus Idiophyton, Yunnan
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| Habit of Lysimachia longiracemosa. A-B. Plant in the habitat, showing an erect subshrub habit. C. Plant with horizontally extending inflorescence. A is vouched by Z.X.Ma 2466, and B-C are vouched by the type gathering Z.X.Ma 2408. Photographs: Z.X. Ma. |
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| Inflorescence and flower of Lysimachia longiracemosa. A-D. Racemes from multiple individuals were compared, noting their horizontally extending axis with pendulous flowers, which superficially resembles to a helicoid cymose inflorescence. E-G. Flowers from different views. H. Flower dissected, note half of the calyx and corolla are artificially removed, displaying the robust anthers with minute filaments. I. Flower dissected, showing the glabrous pistil. All images are vouched by the type gathering Z.X.Ma 2408. Photographs: Z.X. Ma. |
Lysimachia longiracemosa Y.H.Tan & Z.X.Ma, sp. nov.
Diagnosis: Lysimachia longiracemosa is morphologically similar to L. nutantiflora, but differs in having unwinged stems (vs winged stems), basally branched racemes that often develop the lowest branch into a paniculate unit and extend horizontally, smaller lanceolate bracts with the lowest 0.2–0.4 × 1.0–1.8 cm that abruptly reduce upward to nearly indistinct narrowly lanceolate to subulate bracts ca. 0.4 × 0.2 mm (vs. leaflike, elliptic to lanceolate, lowest bracts ca. 2.8 × 1.5 cm, gradually reduced upward to ca. 4 × 1.5 mm), and calyx medium green (vs. dark purple).
Zhengxu Ma, Dongli Quan and Yun-Hong Tan. 2026. Lysimachia longiracemosa (Primulaceae: Lysimachieae), A New frutescent herb from Yunnan, China. Taiwania. 71(1); 32-36 DOI: 10.6165/tai.2026.71.32 [2026 January 04]
