Swertia L.

Erect, procumbent, climbing or cushion-forming annual or perennial herbs, with or without basal leaf rosettes; sometimes with thick rootstock. Stems very reduced in acaulescent rosette plants or up to 1.5 m long, branching from the base or unbranched apart from the inflorescence, 4-angled, angles smooth or minutely scabrid-denticulate usually at the nodes. Leaves decussate or rarely whorled or alternate; basal rosette leaves falling early or persistent, with ± winged petiole or sessile (e.g. some populations of S. schimperi); cauline leaves sessile or narrowed at the base, sometimes amplexicaul, sometimes forming long sheaths, usually with 3–5 distinct dorsal veins; the base of the leaves with one row of colleters all around, at the margins or in the median. Inflorescence a thyrse, botryoid or corymb, single-to many-flowered; pedicels often long and distinct. Flowers 4–5 (rarely 6–7)-merous. Calyx lobes divided to the base, usually ± unequal, 2–3 wider and longer than the remaining segments, persistent, with one row of colleters at the base of the inner surface. Corolla rotate, persistent in fruit, imbricate in aestivation (contorted to the left or sometimes paratact); tube short; lobes with 1–2 nectaries (small pits) at the base; nectaries flat or pocket-like, margins naked or fimbriate, fimbriae 4–25, free or connate at the base. Stamens epipetalous with slender, subulate or dorsiventrallyflattened filaments inserted in the sinuses of corolla lobes, with or without scale-like projections at their attachment points; anthers with 2 thecae, oblong or ellipsoidal, versatile or dorsifixed, with or without apical appendages. Gynoecium bicarpellate; style obsolete or distinct; stigma bilobed, lobes becoming more distinct in fruiting stage; ovary oblong or ovoid, unilocular, parietal placentae large, conspicuous or indistinct; ovules (few-)numerous. Capsule light grey or purplish, dehiscing septicidally into 2 valves. Seeds light brown or grey, few to numerous, smooth, winged or with ridge-like outgrowths, the outgrowths continuous or interrupted in outline.