Lysimachia coriacea S.R. Yi & H.F. Yan, 2022

Yan, Hai-Fei, Huang, Ya, Zhang, Hong-Jing & Yi, Si-Rong, 2022, Lysimachia coriacea (Primulaceae, Myrsinoideae), a new species from Chongqing, China, PhytoKeys 215, pp. 87-94 : 87

Lysimachia coriacea S.R. Yi & H.F. Yan sp. nov.

Figs 1 , 2

Type.

China. Chongqing: Nanchuan District, Nanping Town, Shangenqiao , 29°02'N, 107°08'E, 740 m a.s.l., 28 April 2019, Si-Rong Yi YSR8174 (holotype IBSC!; isotypes KUN!) .

Diagnosis.

The new species belongs to subgen. Lysimachia sect. Nummularia ser. Paridiformes Chen & Hu (1979: 36) characterized by verticillate upper leaves, scale-like lower leaves and umbellate inflorescence. It is similar to L. paridiformis var. stenophylla in having scale-like lower leaves, upper leaves in a terminal whorl and terminal umbels, but it is easily distinguished by its smaller and leathery leaves (vs. papery) only with black glandular stripes near the margin (vs. black glandular stripes on the whole leaf blade), pedicels with dense stalked glands (vs. glabrous), and corollas without black glandular stripes (vs. occasionally with black glandular stripes) ( Hu and Kelso 1996). At first glance, it also looks similar to L. nanpingensis , but differs by its smaller leathery leaves (vs. papery) and densely glandular stem, petiole and pedicel (vs. densely fulvous pubescent), and glabrous calyx lobes with sparse black glandular stripes (vs. pubescent and sparsely reddish glandular punctate). A more detailed comparison of the three species is provided in Table 1 .

Description.

Herbs perennial, 5-15 cm tall. Rootstock with numerous fibrous roots. Stem terete, erect or lower part procumbent, rooting at nodes, simple or branched, with dense stalked glands when young. Leaves opposite, lowest 1-2 pairs scale-like, upper 2-3 pairs closely crowded; blades elliptic or ovate-elliptic, 1.8-3.5 × 1.0-1.8 cm, leathery, adaxially dark green, smooth and glabrous, lustrous; abaxially light green, glabrous, black glandular striate near entire margin, base cuneate, apex acute, mid-vein impressed above, raised below, lateral veins and veinlets inconspicuous; petiole 5-15 mm long, with dense stalked glands. Flowers 1-5, crowded at apex of stems, bracts oblanceolate, 6 mm long, green, sparsely glandular; pedicel 6-15 mm long, with dense stalked glands, erect in fruit; calyx lobes narrowly lanceolate, 4.5-6.8 × 0.9-1.5 mm, divided to base, apex acuminate, abaxially sparsely black glandular striate, margin glandular, membranous; corolla yellow, tube 2-3 mm high, lobes elliptic, 6-9 × 5.5-6.8 mm, apex obtuse or slightly emarginate; filaments connate basally into a tube, ca. 2 mm high, with dense granular glandular spots, free parts 2-3 mm long; anthers oblong, 0.8-1.2 mm long, dorsifixed; ovary subglobose, 0.9-1.2 mm in diam., glabrous; style 4.5-6.0 mm long, glabrous. Capsule subglobose, 2.5-4.5 mm in diam.

Distribution and habitat.

Lysimachia coriacea is only known from the western slopes of Jinfo Mountain, Nanchuan, Chongqing, China. It grows on damp rocks or cliffs in forests, along roadsides and in mountain valleys at elevations of 740-1,300 m.

Conservation status.

This new species has only been found on Jinfo Mountain with at least four populations, where its area of occupancy is less than 10 km2. Fortunately, the current distribution area of the species is under the protection of the Jinfo Mountain National Natural Reserve. Thus, it is assigned the status of "Least Concern" (LC) according to the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Committee 2022).

Phenology.

Flowering from April to May and fruiting from May to June.

Etymology.

Latin coriacea, leathery, alluding to texture of leaves.

Chinese name.

革叶过路黄 ( Gé Yè Guò Lù Huáng).

Additional specimens examined.

China. Chongqing: Nanchuan District, Nanping Town, Shangenqiao , 29°02'N, 107°08'E, 740 m a.s.l., in shady fissures of wet rocks, 7 June 2019, Si-Rong Yi YSR8004 (KUN1510469!); Nanchuan District , Nanping Town , Huangniya, on a damp rocky roadside, 1,300 m a.s.l., 28 May 1986, Z. Y. Liu 0663 (PE01895529!); Nanchuan District , Dutouma (from Lanba to Sanhui), on the roadside, 860 m a.s.l., 7 May 1957, J.H. Xiong & Z.L. Zhou 90705 (IBSC0019656!); Nanchuan District , Sanhui Dianchanggou, on a damp rock in forests, 970 m a.s.l., 5 July 1957, J.H. Xiong & Z.L. Zhou 91820 (IBSC0019657!) .

Notes.

Specimens of the new species were first collected by Ji-Hua Xiong and Zi-Lin Zhou in 1957 and deposited in IBSC (IBSC0019656 and IBSC0019657). The two specimens were identified as " Lysimachia paridiformis var. stenophylla Franch." by Chi-Ming Hu. However, Hu should also notice the differences between this specific taxon and L. paridiformis var. stenophylla , because he wrote a temporary name " Lysimachia nitida Chen et C.M. Hu" on the annotation labels of the specimens. Later, specimens of the new species were collected by some other collectors (see above).

Figures

Figure 1. Lysimachia coriacea A habit B leaf C flower D calyx lobes, abaxial view (right) and adaxial view (left) E, F opened corolla, showing filaments connate at base G anthers, front view (left) and back view (right) H pistil I flower with corolla removed J young fruit with persistent calyx. Drawn by Yun-Xiao Liu.

Figure 2. Lysimachia coriacea A flowering plants B inflorescence C fruiting plants D flowers E, F leaves G flower with corolla removed H calyx, abaxial view I calyx, adaxial view J corolla, abaxial view K corolla, adaxial view L-M stamens N pistil O young fruits. Photographed by Si-Rong Yi.