Wall.
Description
Lysimachia lobelioides is a slender herb ranging widely through the Himalaya and Southeast Asia, recorded from China, India, Bhutan, Nepal, Myanmar, Thailand, Laos, Vietnam, Taiwan and New Caledonia, with 647 occurrences logged in GBIF. It favours moist, shaded and disturbed places at low to middle elevations: stream banks, ditches, damp grassy ground, field margins and open forest, broadly between 300 and 2500 m. The Bhutanese collection illustrated, from the Mo-Chu valley at 1350 m in June, typifies its occurrence in warm subtropical river-valley habitats during the early monsoon, when it flowers freely on damp, fertile soils.
It is an annual or short-lived perennial with weak, erect to decumbent, often quadrangular stems 10-40 cm long, glabrous and sometimes rooting at the lower nodes. The leaves are alternate, ovate to lanceolate, thin in texture, shortly petiolate and frequently dotted with dark glandular punctations. The small flowers are borne singly in the upper leaf axils on filiform pedicels; the corolla is white to pale pink, deeply five-lobed and shorter than or about equalling the lanceolate calyx lobes, with five stamens. The fruit is a small globose capsule dehiscing by valves and releasing numerous minute angular seeds.
Lysimachia (Primulaceae, formerly Myrsinaceae in part) is a large, near-cosmopolitan genus best developed in eastern Asia; L. lobelioides belongs to a group of small-flowered, axillary-flowered annuals. Its wide distribution, weedy tendency and tolerance of disturbed wet ground make it ecologically adaptable and of no conservation concern. The disjunct New Caledonian records are biogeographically notable, pointing to long-distance dispersal of this colonising species across the Indo-Pacific.
Author: Wall. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Revision of the Genus Lysimachia (Primulaceae)