Alternative common names:
Heart-leaf four-o’clock, heart-leaf umbrella-wort, snotweed, umbrella-wort. (English), Vieruurtjie (Afrikaans).
Four o' clock is a bushy, tender perennial that typically grows tall on erect, branching stems. It is an old garden favorite that features fragrant, funnel-shaped, tubular flowers with five flaring petal-like lobes. Flowers bloom from early/mid-summer to autumn. Flowers open in the late afternoon (around four o'clock) and stay open only until the following morning.
Where does this species come from?Tropical America.
What is its invasive status in South Africa?NEMBA Category 1b.
Where in South Africa is it a problem?Largely confined to Gauteng Province, with scattered records from Limpopo, Mpumalanga and North West Province.
How does it spread?They reproduce and spread from seeds. This shrub thrives in summer during the rainy season.
Why is it a problem?
Regarded as a minor environmental weed or "sleeper weed" in many parts of the world. It is capable of withstanding extended droughts due to the tuberous roots. It has potential to out compete indigenous vegetation. The seeds and plant are poisonous if ingested.
What does it look like?
Leaves: Opposite, slightly pointed oval leaves and multi-branching stems.
Flowers: Trumpet-shaped, five-petal flowers come in pink, red, yellow, white and some bi-colours. 30-50mm long. Flowers have a slight vanilla scent and open in the late afternoon through the evening.
Fruit/seeds: The seeds are egg-shaped, hairy and greyish brown, with five lengthwise ribs. The fruit is a small, one-seeded capsule (anthocarp). Rounded nut-like fruit 7-11mm long and turning wrinkled and black when mature.
Does the plant have any uses?
Largely planted as a garden ornamental. The flowers are used as food colouring. Leaves may be eaten cooked as well but only as an emergency food.