Cosmos sulphureus Cav.

Species Classification

Cosmos sulphureus Cav. is a half-hardy annual species of Cosmos, though individual plants may re-appear for several years through self-sowing.

Foliage and Size

It has opposite, pinnately divided foliage, and reaches a height between 1 and 7 feet (30 to 210 cm).

Flower Characteristics

Both the original species and its cultivars have flower shades of yellow, orange, and red.

Regional Popularity

The species is especially popular in Korea and Japan, where it is commonly grown in mass plantings along roadsides as part of an initiative led by Korean-Japanese botanist Woo Jang-choon.

Germination and Flowering Timeline

For cultivation, the species has the following growth characteristics: germination occurs in 7 to 21 days at an optimal temperature of 75 degrees Fahrenheit, and flowering starts 50 to 60 days after germination.

Soil Preference

It prefers soil with a pH between 6.0 and 8.5, which matches its native habitat in the alkaline regions of Central America.

Light Requirements

It produces the best flowering in full sun, though it can tolerate partial shade.

Hardiness and Pest Status

After germination, it is drought-tolerant and is rarely damaged by insects or disease; this strong growth has led to it being classified as a pest in some areas of the United States.

Culinary Use in Indonesia

For uses, young shoots of this plant are eaten raw or cooked in Indonesia, where it is known as lalab or gudang.

Dye Production

Its flowers produce an orange-yellow dye, which was used in pre-Columbian America and later in southern Africa to dye wool.

Uses in Thailand

In Thailand, the flowers are eaten in salads or made into herbal tea, and are reported to have an inhibitory effect on pancreatic lipase.

2017 Hepatoprotective Study

A 2017 study by a Pakistani research team found that plant extract had a hepatoprotective effect in rats given a high dose of paracetamol.

Baking Application Study

A 2017 Ukrainian publication gave high organoleptic ratings to bread made with 10% dry extract of Cosmos sulphureus.