Tetranema

The genus name Tetranema (Tetranema) derives from Latin tetra – four and nema – filament; the flowers of this plant have four stamens.

This is a perennial herbaceous plant with a short, shortened stem. Leaves oval, shortly petiolate, scalloped, 10–13 cm long. Flower stalks short, up to 12 cm high. Flowers bilabiate, purple-violet, gathered in dense umbel-like inflorescences. Flowers from June – September.

Mexican Tetranema – (Tetranema mexicana)

Herbaceous perennial with a shortened stem. Leaves closely spaced, up to 13 cm long, shortly petiolate, oval or narrowly obovate, pointed, narrowed at the base, glabrous, with an indistinctly toothed or scalloped turned margin. Flowers up to 1.7 cm long, gathered in umbel-like, dense inflorescences on flower stalks that are reddish at the base, up to 12 cm high, arising from the leaf axils. Calyx 5-parted, deeply divided into thin segments. Corolla lilac with darker spots, funnel-shaped, bilabiate with a curved tube.

Location: Tetranema is light- and warmth-loving. In bright sunlight it requires shading. Winter temperature 16-20 °C.

Humidity: the plant is not demanding regarding air humidity.

Watering: water Tetranema moderately with soft, settled water.

Care: during the growing period feed once a month with liquid flower fertilizers. Repot annually in spring. Use a soil mix of turf soil, leaf mold, humus, peat and sand (2:1:1:1:1).

Propagation: by cuttings and daughter rosettes.

Possible problems: flower stalks may be affected by aphids. Spraying with an infusion of pyrethrum or tobacco with added soap helps against the pest. In case of severe infestation the plant is sprayed with a solution of Actellic. A white powdery coating on the leaves indicates powdery mildew. Dusting with sulfur is a control measure. If the disease is severe, spraying with Fundazol is necessary.