Aloysia citriodora Paláu, 1784, non Lam. 1791

Aloysia species are herbs or undershrubs. Leaves opposite or whorled, exstipulate. Inflorescence cymose, racemose or spike. Flowers bisexual, sessile or pedicellate, usually zygomorphic, Calyx gamosepalous, Corolla 4 lobed, gamopetalous, Stamens 4, Anthers dorsifixed, Ovary entire or 4 lobed, Fruit is schizocarp.

Aloysia species flowers are bisexual i.e., with functional male (androecium) and female (gynoecium), including stamens, carpels and ovary. Pollination is entomophilous i.e., by insects. Flowering/Fruiting: June-September.

Seeds dispersed by anemochory i.e., wind dispersal, epizoochory i.e., dispersal by animals externally, anthropochory i.e., dispersal by humans.

Herbaceous perennial herb about 2-4 ft tall. Leaves opposite or 3-whorled, lanceolate 6-10 x 1-2.5 cm across, base shallowly acuminate, margin entire, apex shallowly cuspidate to acuminate, lateral veins 25-35 on either side of the midvein, Petiole 0.3-0.6 cm long, exstipulate. Inflorescence pedicellate on axillary racemose spikes, flower branches indeterminate, terminal as well as distal on branches, usually found in clusters of 3-6. Flowers bisexual, weakly actinomorphic or zygomorphic with purple Corolla tube and white lobes, with very short pedicel, bracts lanceolate, Calyx tubular, 2.5–4 mm long, Corolla tube 3.5–5 mm long purple in color, cylindrical to gibbous, Corolla 4 lobed. Stamens 4, anthers yellowish, Styles filiform, Stigma capitates, bilobed, Fruit Schizocarp, ellipsoid, truncate at the base.

Susceptible to insect pests.

Open areas

Native of South America cultivated in Nilgiri hills of Tamil Nadu.

Leaves and flowers are used in manufacturing cosmetics, perfumes and herbal medicine. Also favouring fish, poultry, preparing salads, desserts, jams, essential oil and tea.