Lobelia sect. Rhynchopetalum (Fresen.) Benth.

Lammers, Th. G., 2011, Revision of the Malesian species of Lobelia section Rhynchopetalum (Campanulaceae: Lobelioideae), Blumea 56 (3), pp. 218-224 : 219

Lobelia sect. Rhynchopetalum (Fresen.) Benth.

Lobelia sect. Rhynchopetalum (Fresen.) Benth. in Bentham & Hooker (1876) 552. — Rhynchopetalum Fresen. (1838) 603. — Tupa sect. Rhynchopetalum (Fresen.) A.Rich. (1850) 9. — Type [sub Art. 37.3]: Rhynchopetalum montanum Fresen. [≡ Lobelia rhynchopetalum Hemsl. ]. Complete heterotypic synonymy will be found in Lammers (2011).

Plants perennial or pliestesial, sometimes rhizomatous. Stems typically robust or even pachycaul, 0.2 – 9 m tall, herbaceous, suffruticose, or woody, simple or branched, prostrate, decumbent, ascending, or erect. Leaves sessile (rarely petiolate), cauline or rosulate. Flowers resupinate, epigynous, zygomorphic, pedicellate, in a terminal bracteate anauxotelic raceme or panicle; pedicels bibracteolate or ebracteolate. Corolla sympetalous, typically for half or more of its length, bilaterally symmetric, unilabiate with 5 ventral lobes or sub-bilabiate with 2 dorsal and 3 ventral lobes, various shades of blue, purple, red, yellow, green, or white, 12 –50 mm long; tube curved or arcuate; lobes spreading or defexed, as long as the tube or longer. Stamens connate distally, forming an exserted and dorsally deflected staminal column free from the corolla tube; anthers bearded with tufts of filiform hairs at apex of ventral pair or all anthers nude at apex. Ovary completely or partially inferior; placentae axile; ovules numerous. Fruit a capsule, loculicidally dehiscent by an apical pair of triangular valves. Seeds small, numerous, ovoid, lenticular, commonly winged; testa striate-reticulate. Chromosome number 2n = 28 ( Lammers 1993, Knox & Kowal 1993, Ruas et al. 2001).

Distribution — Twelve species in south-eastern Brazil (one extending into adjacent Argentina and Paraguay); 25 species in tropical Africa, from the Gulf of Guinea to Angola, Transvaal, and Ethiopia; and 25 species in southern and eastern Asia, from Sri Lanka and India to eastern China, the Bonin Islands, Taiwan, and Malesia (one extending north to eastern Siberia, the Russian Far East, the Kuriles, Korea, and Japan).