Lysimachia pubiflora Q. L. Gan, Z. Y. Li & H. Xu, 2024

Xu, Han, Xu, Song-Zhi, Gan, Qi-Liang & Li, Zhen-Yu, 2024, Lysimachia pubiflora (Primulaceae), a new species from Hubei, China, PhytoKeys 249, pp. 269-275 : 269-275

Lysimachia pubiflora Q. L. Gan, Z. Y. Li & H. Xu sp. nov.

Figs 1 , 2

Diagnosis.

Lysimachia pubiflora is most similar to L. jinzhaiensis in several characteristics, including the quadrangular stems, glandular striations on the leaves, calyx, and corolla, as well as the presence of axillary solitary flowers featuring unequal calyx lobes. It also shares a yellow corolla with an orange-red base. However, L. pubiflora can be distinguished from L. jinzhaiensis by the presence of flagelliform runners on the stems (vs. absent in L. jinzhaiensis ), pilose young stems and calyx lobes (vs. glabrous in L. jinzhaiensis ), calyx lobes 4.5–5 mm long (vs. 6–8.5 mm long), and anthers 1.1–1.3 mm long (versus ca. 1.5 mm long). The new species can easily be distinguished from all other species in Sect. Nummularia by its glandular-pubescent corolla.

Type.

China • Hubei Province, Fangxian County, Hongta Town, Nantang Village , alt. 712 m, 12 June 2024, Qi-Liang Gan 4450 (holotype, PE!) .

Paratypes. China • Hubei: Fangxian County, Yerengu Town, Tanjiawan Village , alt. 697 m, 12 June 2024, Qi-Liang Gan 4447 ( PE!) • Fangxian County, Yerengu Town, Tanjiawan Village , alt. 697 m, 12 June 2024, Qi-Liang Gan 4448 ( PE!) • Fangxian County, Hongta Town, Nantang Village , alt. 712 m, 12 June 2024, Qi-Liang Gan 4449 ( PE!) .

Description.

Herbs perennial. Rhizome horizontal, below-ground, 5–12 cm long, with adventitious roots at the nodes; stems usually 3–5 caespitose, 50–120 cm long, quadrangular, pubescent, at least when young, with a spreading habit, distal parts of stems and branches usually slender and smaller leaved, forming the flagelliform runners that usually root at the 1–3 distal nodes. Leaves opposite, rarely 3 - whorled in the upper section of stems; petioles 0.5–2.5 cm long, adaxial sides shallowly grooved, abaxial sides rounded, narrowly winged, margins pilose, amplexicaul at the base; leaf blades broadly ovate to deltoid-ovate, 1.5–9.5 cm long, 1–6.5 cm wide, with acute or subobtuse apices, broadly cordate, subrounded or truncate, rarely cuneate at the base (on the runners), margins entire or slightly undulate, densely scattered with transparent glandular striations that sometimes turn purple when dry, glabrous adaxially, and abaxially sparsely pubescent along the midrib when young, becoming glabrate with age; lateral veins in 4–6 pairs, with the lowest 1–2 pairs arising from the base, the others alternating, midrib and lateral veins impressed adaxially, raised adaxially, veinlets inconspicuous. Flowers solitary in axils of leaves; pedicel 1.1–2.5 cm long, usually shorter than subtending leaves, sparsely pubescent. Calyx 5–5.5 mm long, 5 – parted almost to the base, connate part ca. 0.5 mm, lobes elliptic or elliptic-lanceolate, unequal, 4.5–5 × 1.5–2 mm, densely transparent glandular striate, the stripes becoming purple when dry, sparsely pilose outside; corolla yellow, with an orange or orange-red base, rotate, 2–2.3 cm in diam., 5 - parted, tube 1–1.5 mm long, lobes narrowly lanceolate, 10–12 mm long, 2.5–3 mm wide, sparsely transparent glandular striate, the stripes becoming black-purple when dry, glabrous inside, glandular-pubescent outside and along margins; stamens 5, adnate to the base of the corolla tube, erect, yellow, glabrous, filaments basally connate into a tube ca. 2 mm long, free parts 4–6 mm long, anthers basifixed, oblong, 1.1–1.3 mm long, open by lateral slits; pistil glabrous, ovary globose, ca. 1.5 mm in diameter, the style filiform, 7–8 mm long, stigma obtuse, slightly wider than the style. Capsule subglobose, 3–4 mm in diam., glabrous. Seeds dark brown, rhombic, 0.5–1 mm long, 3–4 angled, glabrous.

Phenology.

Flowering from late May to early July; fruiting from mid-July to late August.

Distribution and habitat.

This species is endemic to two specific townships in Fang County, confined to a narrow limestone valley that lies between the neighboring villages of Tanjiawan and Nantang. It is observed along roadsides, within water ditches, in sparse shrublands on hillsides, and at the edges of sparse forests. The elevation of its habitat ranges from 690 to 712 meters.

The main companion plant species include trees such as Populus adenopoda Maxim. , Quercus serrate var. brevipetiolata (A. DC.) Nakai , Platycarya strobilacea Sieb. & Zucc. , Broussonetia papyrifera (L.) L’Hér. ex Vent., Vernicia fordii (Hemsl.) Airy Shaw , Pinus massoniana Lamb. ; shrubs such as Cotinus coggygria var. pubescens Engl. , Mallotus apelta (Lour.) Müll. Arg. , Buddleja officinalis Maxim. , Pyracantha fortuneane (Maxim.) Li , Zanthoxylum armatum DC. , Coriaria nepalensis Wall. , Rhus chinensis Mill. , Salix wallichiana Anderss. , Indigofera bungeana Walp. , Ficus heteromorpha Hemsl. , Lindera glauca (Sieb. & Zucc.) Bl. , Rosa banksiae var. normalis Regel. Herbaceous plants consist of Miscanthus floridulus (Lab.) Warb. ex Schum. & Laut. , Anemone hupehensis Lem. , Geum japonicum var. chinense F. Bolle , Agrimonia pilosa Ledeb. , Duchesnea indica (Andr.) Focke , Aster albescens (DC.) Hand. - Mazz., Leersia japonica (Makino) Honda , Pteridium aquilinum var. latiusculum (Desv.) Underw. ex A. Heller , Pteris vittata L., Cyrtomium tsinglingense Ching & K. H. Shing ex K. H. Shing , and others. Vines include Clematis armandii Franch. , Biancaea decapetala (Roth) O. Deg. , Dalbergia mimosoides Franch. , and Smilax glauco-china Warb.

Etymology.

The epithet ‘ pubiflora ’ refers to the glandular-pubescent corolla. Vernacular name: Mao Hua Guo Lu Huang (Chinese).

Conservation assessment.

This species inhabits a narrow limestone valley, extending approximately ten kilometers in straight-line distance between two villages. The region is characterized by significant limestone exposure and thin, infertile soil layers, reflecting a fragile natural ecosystem. This ecosystem is highly susceptible to human activities. Following its initial discovery in 2014, the species has shown significant population fragmentation due to road construction, deforestation for agriculture, and livestock grazing. The current population size is estimated to consist of around one thousand individuals. Based on the IUCN Guidelines (Version 16) ( IUCN 2024), the species may be classified as ‘ Endangered’.

Figures

Figure 1. Lysimachia pubiflora sp. nov. A plant at early flowering stage B mature individual C rhizome and adventitious roots D stem E cross section of stem F pubescent young stem G upper part of flagelliform runner, showing the distal nodes with adventitious roots H leaves I larger leaves with broad-cordate base J, K petioles L, M glandular stripes on leaf blades usually transparent (L when fresh, M dried).

Figure 2. Lysimachia pubiflora A plants at full-bloom B, C flowering branches D axillary flowers E flower bud F pedicel G calyx (adaxial view) H calyx (lateral view) I corolla J a lobe of corolla (abaxial view) K stamens L capsule with persistent calyx M seeds.