Lobelia sessilifolia

Lobelia sessilifolia is a perennial in the bellflower family, Campanulaceae. Its native range spans eastern Siberia, China, Korea, and Japan. It also grows in the Russian Far East, including Sakhalin and the southern Kuril Islands. This range lies within temperate Asia. In Japan, it grows in wet sites in both lowlands and mountains. It is not native to Britain or Ireland. The RHS lists Lobelia sessiliflora as a synonym.

Plants reach about 2.3 feet (0.7 metres) tall. Their spread reaches about 1 foot (0.3 metres). These dimensions suit a small space within a wet planting. Plants For A Future records flowering in August. Each flower has both male and female organs. The supplied species records give no flower colour or fruit details. They also give no detailed account of leaves or stems. The RHS flower description covers the genus, rather than this species.

Wet ground is the key growing need in cultivation. Plants For A Future lists both moist and wet soils. Its cultivation note calls for wet soil, making a bog garden a suitable setting. The plant can grow in full sun or light shade. It accepts sandy soil, loam, and clay. Its stated pH range runs from mildly acid to mildly alkaline. The source lists USDA zones 4–8. It also gives an older UK zone number, not an RHS H rating.

Growers can raise plants from seed or divide them in spring. Sow fresh, ripe seed in a cold frame. Move seedlings into separate pots once large enough to handle. Keep them in a greenhouse through their first winter. Plant them out after the last expected frost. Spring basal cuttings offer another way to raise plants. Each cutting needs some underground stem attached. Keep potted cuttings in light shade until they root well. Stems can also root at their nodes when layered in moist sand.

Treat this plant with caution because it contains toxic alkaloids. One is lobeline, which affects the nervous system in a nicotine-like way. Reports describe cooked buds and young plants as famine food. That history does not remove the stated poisoning risk. Plants For A Future also lists leaves among its edible parts. It records no known medicinal or other uses. Its weed-potential entry does not flag the species as weedy.