- Name also: Branched Centaury, Branching Centaury
- Family: Gentian Family – Gentianaceae
- Growing form: Annual herb.
- Height: 3–15 cm (1.2–6 in.). 1-stemmed. Stem unbranched or upper part many-branched, glabrous.
- Flower: Corolla regular (actinomorphic), pink, approx. 0.5 cm (0.2 in.) wide, fused, 5-lobed, long and narrow tube. Calyx almost with separate leaves, 5-lobed, clearly shorter than corolla. Stamens 5, anthers protruding from calyx-tube. Gynoecium composed of 2 fused carpels. Flowers solitary–in pairs.
- Leaves: Opposite, stalkless, lowest often smaller than others. No basal rosette. Blade narrowly elliptic–lanceolate, with tapered tips and entire margin, 3-veined.
- Fruit: 2-parted capsule.
- Habitat: Silt and clay sea-shores, shoreside meadows.
- Flowering time: July–August.
- Endangerment: Near threatened.
Sometimes lesser centaury is only an inch tall and may even be missed by observant botanists in among larger seaside plants. Large specimens do not catch the eye before flowering time. Its flowers are attractively rose red, small and open only from late morning until early evening. On cloudy days they stay tightly shut with the corolla lobes closed in upon each other. With respect to its size, lesser centaury invests a lot of its resources in flowering and sexual reproduction. The large quantity of seed it produces is a necessity for a species with an annual life cycle and which grows in the fickle conditions of the seashore. Only very few seeds develop new, flowering lesser centaury, and the abundance of the species varies dramatically from one year to another.
Like its close relatives the gentians, centaury contains bitter substances which have led the plant to be used medicinally in earlier times. Centaury’s scientific name comes from its traditional association with the centaurs of Greek mythology – beasts that were half man, half horse. They have been described as gifted healers and they used centaury as a drug. According to another theory, however, the name has been derived from the words centum aureum, which mean 100 sovereigns and refer to centaury’s medicinal power. In any case centaury’s name has come from its use as a medicinal, especially in the treatment of stomach, kidney and period pains and also gout. Finnish centauries have been used too, although they are small and often lean, so it was hard work collecting enough plants to make the medicine.
Lesser centaury grows on sea shores around Pori, to the mouth of the River Kokemäki, in the same places as its close relative seaside centaury (C. littorale). They cannot be classified according to their size alone because seaside centaury is often only slightly bigger. Seaside centaury is a biennial which develops a leaf rosette in its first growing season and then flowers the following summer, but lesser centaury does not have a leaf rosette.